WorldWideScience

Sample records for modified asphalt concrete

  1. Investigation of modified asphalt concrete

    Science.gov (United States)

    Zimich, Vita

    2016-01-01

    Currently the problem of improving the asphalt quality is very urgent. It is used primarily as topcoats exposed to the greatest relative to the other layers of the road, dynamic load - impact and shear. The number of cars on the road, the speed of their movement, as well as the traffic intensity increase day by day. We have to upgrade motor roads, which entails a huge cost. World experience shows that the issue is urgent not only in Russia, but also in many countries in Europe, USA and Asia. Thus, the subject of research is the resistance of asphalt concrete to water and its influence on the strength of the material at different temperatures, and resistance of pavement to deformation. It is appropriate to search for new modifiers for asphaltic binder and mineral additives for asphalt mix to form in complex the skeleton of the future asphalt concrete, resistant to atmospheric condensation, soil characteristics of the road construction area, as well as the growing road transport load. The important task of the work is searching special modifying additives for bitumen binder and asphalt mixture as a whole, which will improve the quality of highways, increasing the period between repairs. The methods described in the normative-technical documentation were used for the research. The conducted research allowed reducing the frequency of road maintenance for 7 years, increasing it from 17 to 25 years.

  2. Percolation Model of Graphite-modified Asphalt Concrete

    Institute of Scientific and Technical Information of China (English)

    MO Liantong; WU Shaopeng; LIU Xiaoming; CHEN Zheng

    2005-01-01

    The addition of graphite powder in conventional asphalt mixture can produced asphalt concrete with excellent electrical performance. Percolation theory was employed to discuss the relation between the conductivity and graphite content of graphite-modified asphalt concrete. It was found that the results of percolation model are consistent with experimental values. The percolation threshold of graphite-modified asphalt concrete is 10.94% graphite content account for the total volume of the binder phase consisting of asphalt and graphite. The critical exponent is 3.16, beyond the range of 1.6-2.1 for the standard lattice continuous percolation problem. Its reason is that the tunnel conduction mechanism originates near the critical percent content, which causes this system to be not universal. Tunnel mechanism is demonstrated by the nonlinear voltage-current characteristic near percolation threshold.The percolation model is able to well predict the formation and development of conductive network in graphite-modified asphalt concrete.

  3. THE FATIGUE DURABILITY OF THE MODIFIED ASPHALT CONCRETE UNDER THE EFFECT OF INTENSIVE TRAFFIC LOADS

    Directory of Open Access Journals (Sweden)

    Yuri KALGIN

    2016-06-01

    Full Text Available The problem of prediction of the service life of asphalt concrete surface constructed with modified asphalt concrete application onto a traffic lane is examined. Asphalt concrete behaviour in road surface under the traffic loads was analysed. There were shown The results of experiments and their mathematical analysis of the assessment of standard and modified cold asphalt concrete fatigue life on road surface were shown. The service life of an asphalt concrete surface covered with standard and modified cold asphalt concrete is examined. The prediction has been received with an account of stress relaxation processes in asphalt concrete pavement and unevenness of traffic load application.

  4. Thermal behavior of crumb-rubber modified asphalt concrete mixtures

    Science.gov (United States)

    Epps, Amy Louise

    Thermal cracking is one of the primary forms of distress in asphalt concrete pavements, resulting from either a single drop in temperature to an extreme low or from multiple temperature cycles above the fracture temperature of the asphalt-aggregate mixture. The first mode described is low temperature cracking; the second is thermal fatigue. The addition of crumb-rubber, manufactured from scrap tires, to the binder in asphalt concrete pavements has been suggested to minimize both types of thermal cracking. Four experiments were designed and completed to evaluate the thermal behavior of crumb-rubber modified (CRM) asphalt-aggregate mixtures. Modified and unmodified mixture response to thermal stresses was measured in four laboratory tests. The Thermal Stress Restrained Specimen Test (TSRST) and the Indirect Tensile Test (IDT) were used to compare mixture resistance to low temperature cracking. Modified mixtures showed improved performance, and cooling rate did not affect mixture resistance according to the statistical analysis. Therefore results from tests with faster rates can predict performance under slower field rates. In comparison, predicted fracture temperatures and stresses (IDT) were generally higher than measured values (TSRST). In addition, predicted fracture temperatures from binder test results demonstrated that binder testing alone is not sufficient to evaluate CRM mixtures. Thermal fatigue was explored in the third experiment using conventional load-induced fatigue tests with conditions selected to simulate daily temperature fluctuations. Test results indicated that thermal fatigue may contribute to transverse cracking in asphalt pavements. Both unmodified and modified mixtures had a finite capacity to withstand daily temperature fluctuations coupled with cold temperatures. Modified mixtures again exhibited improved performance. The fourth experiment examined fracture properties of modified and unmodified mixtures using a common fracture toughness test

  5. Crumb rubber modified asphalt concrete in Oregon. Summary report. Report for 1985-94

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, E.; Peters, W.

    1995-07-01

    Over the last nine years, the Oregon Department of Transportation (ODOT) has constructed 13 projects using crumb rubber modifiers (CRM) in asphalt concrete pavements using both the wet and dry process. State and federal legislation may require the use of recycled rubber in asphalt concrete, therefore, the Oregon Department of Transportation is interested in determining the most cost -effective crumb rubber modified asphalt concrete. The report includes a literature review on the use of crumb rubber modifiers in asphalt concrete pavement; a review on non-ODOT CRM paving projects constructed by Oregon counties and cities; and the Washington Department of Transportation. In additon, the report summarizes the data collected on all CRM hot mix asphalt concrete pavement projects constructed by ODOT. The ODOT information includes background constitution, cost, and performance data for each of the test and control sections. Finally, the future activities of the project are reviewed.

  6. Performance testing of asphalt concrete containing crumb rubber modifier and warm mix additives

    Science.gov (United States)

    Ikpugha, Omo John

    Utilisation of scrap tire has been achieved through the production of crumb rubber modified binders and rubberised asphalt concrete. Terminal and field blended asphalt rubbers have been developed through the wet process to incorporate crumb rubber into the asphalt binder. Warm mix asphalt technologies have been developed to curb the problem associated with the processing and production of such crumb rubber modified binders. Also the lowered production and compaction temperatures associated with warm mix additives suggests the possibility of moisture retention in the mix, which can lead to moisture damage. Conventional moisture sensitivity tests have not effectively discriminated good and poor mixes, due to the difficulty of simulating field moisture damage mechanisms. This study was carried out to investigate performance properties of crumb rubber modified asphalt concrete, using commercial warm mix asphalt technology. Commonly utilised asphalt mixtures in North America such as dense graded and stone mastic asphalt were used in this study. Uniaxial Cyclic Compression Testing (UCCT) was used to measure permanent deformation at high temperatures. Indirect Tensile Testing (IDT) was used to investigate low temperature performance. Moisture Induced Sensitivity Testing (MiST) was proposed to be an effective method for detecting the susceptibility of asphalt mixtures to moisture damage, as it incorporates major field stripping mechanisms. Sonnewarm(TM), Sasobit(TM) and Evotherm(TM) additives improved the resistance to permanent deformation of dense graded mixes at a loading rate of 0.5 percent by weight of the binder. Polymer modified mixtures showed superior resistance to permanent deformation compared to asphalt rubber in all mix types. Rediset(TM) WMX improves low temperature properties of dense graded mixes at 0.5 percent loading on the asphalt cement. Rediset LQ and Rediset WMX showed good anti stripping properties at 0.5 percent loading on the asphalt cement. The

  7. Evaluation of Fatigue Resistance for Modified Asphalt Concrete Mixtures Based on Dissipated Energy Concept

    OpenAIRE

    Khodary Moalla Hamed, Farag

    2010-01-01

    The performance of asphalt concrete pavement depends on the bitumen properties, asphalt concrete mixtures volumetric properties and external factors such as traffic volume and environment. Bitumen is a visco-elastic material where temperature and rate of load application have a great influence on its behavior. Conventional bitumen is exposed to a wide range of loading and weather conditions; it is soft in a hot environment and brittle in cold weather. Higher traffic volume produces high stres...

  8. Laboratory Performance Evaluation of High Modulus Asphalt Concrete Modified with Different Additives

    Directory of Open Access Journals (Sweden)

    Peng Li

    2017-01-01

    Full Text Available The objective of this study is to evaluate comprehensive performance of high modulus asphalt concrete (HMAC and propose common values for establishing evaluation system. Three gradations with different modifiers were conducted to study the high and low temperature performance, shearing behavior, and water stability. The laboratory tests for HMAC included static and dynamic modulus tests, rutting test, uniaxial penetration test, bending test, and immersion Marshall test. Dynamic modulus test results showed that modifier can improve the static modulus and the improvements were remarkable at higher temperature. Moreover, modulus of HMAC-20 was better than those of HMAC-16 and HMAC-25. The results of performance test indicated that HMAC has good performance to resist high temperature rutting, and the resistances of the HMAC-20 and HMAC-25 against rutting were better than that of HMAC-16. Then, the common values of dynamic stability were recommended. Furthermore, common values of HMAC performance were established based on pavement performance tests.

  9. The Fatigue Behaviour of Asphaltic Concrete Made With Waste Shredded Tire Rubber Modified Bitumen

    OpenAIRE

    ÇELİK, Osman Nuri

    2001-01-01

    Pavement failure can be manifested by excessive cracking due to fatigue. Highway pavements are subjected to a repeated passage of wheel loading of varying magnitude and intensity. Fatigue has been defined as the phenomenon of fracture under repeated or fluctuating stress having a maximum value less than the tensile strength of the material. This paper examines a laboratory characterisation of the fatigue behaviour of rubberised asphaltic concrete and assesses the effect of waste shred...

  10. VISCOELASTIC STRUCTURAL MODEL OF ASPHALT CONCRETE

    Directory of Open Access Journals (Sweden)

    V. Bogomolov

    2016-06-01

    Full Text Available The viscoelastic rheological model of asphalt concrete based on the generalized Kelvin model is offered. The mathematical model of asphalt concrete viscoelastic behavior that can be used for calculation of asphalt concrete upper layers of non-rigid pavements for strength and rutting has been developed. It has been proved that the structural model of Burgers does not fully meet all the requirements of the asphalt-concrete.

  11. Asphalt Mixture for the First Asphalt Concrete Directly Fastened Track in Korea

    Directory of Open Access Journals (Sweden)

    Seong-Hyeok Lee

    2015-01-01

    Full Text Available The research has been initiated to develop the asphalt mixtures which are suitable for the surface of asphalt concrete directly fastened track (ADFT system and evaluate the performance of the asphalt mixture. Three aggregate gradations which are upper (finer, medium, and below (coarser. The nominal maximum aggregate size of asphalt mixture was 10 mm. Asphalt mixture design was conducted at 3 percent air voids using Marshall mix design method. To make impermeable asphalt mixture surface, the laboratory permeability test was conducted for asphalt mixtures of three different aggregate gradations using asphalt mixture permeability tester. Moisture susceptibility test was conducted based on AASHTO T 283. The stripping percentage of asphalt mixtures was measured using a digital camera and analyzed based on image analysis techniques. Based on the limited research results, the finer aggregate gradation is the most suitable for asphalt mixture for ADFT system with the high TSR value and the low stripping percentage and permeable coefficient. Flow number and beam fatigue tests for finer aggregate asphalt mixture were conducted to characterize the performance of asphalt mixtures containing two modified asphalt binders: STE-10 which is styrene-butadiene-styrene (SBS polymer and ARMA which is Crum rubber modified asphalt. The performance tests indicate that the STE-10 shows the higher rutting life and fatigue life.

  12. 新型改性环氧沥青混合料的性能研究%Study on pavement performance of new type modified epoxy asphalt concrete

    Institute of Scientific and Technical Information of China (English)

    张昭; 李璐; 盛兴跃

    2012-01-01

    This paper manufactured a new type modified epoxy asphalt concrete by laboratory experiments. By comparing it' s Marshall performance, high-low temperature performance, and fatigue performance with American epoxy asphalt concrete, we found that the compatibility of new type modified epoxy asphalt concrete was very good, and it' s pavement performance and flexibility was better than American epoxy asphalt concrete, so it is worth being further extended.%通过室内试验,研制出了一种新型改性环氧沥青混合料,并将其马歇尔性能、高低温性能以及疲劳性能与同类进口产品美国环氧沥青混凝土进行了对比分析,发现所研制的新型环氧沥青混合料不仅相容性好,而且具有更优异的路用性能和柔韧性,值得推广应用。

  13. Infiltration Behaviour of Polymer-Modified Porous Concrete and Porous Asphalt Surfaces Used in SuDS Techniques

    OpenAIRE

    Sañudo Fontaneda, Luis Ángel; Rodríguez Hernández, Jorge; Calzada Pérez, Miguel Ángel; Castro Fresno, Daniel

    2014-01-01

    Permeable pavements are one of the world’s most widely applied techniques for source control in sustainable drainage systems. Porous concrete (PC) and porous asphalt (PA) are two of the most studied surfaces in terms of runoff reduction. Nevertheless, previous research has highlighted a lack of a comprehensive laboratory methodology for the analysis of the topographical variables, runoff surface length (RSL) and surface slope (SS), and their impact on the infiltration behaviour of these porou...

  14. The use of waste materials in asphalt concrete mixtures.

    Science.gov (United States)

    Tuncan, Mustafa; Tuncan, Ahmet; Cetin, Altan

    2003-04-01

    The purpose of this study was to investigate (a) the effects of rubber and plastic concentrations and rubber particle sizes on properties of asphalt cement, (b) on properties of asphalt concrete specimens and (c) the effects of fly ash, marble powder, rubber powder and petroleum contaminated soil as filler materials instead of stone powder in the asphalt concrete specimens. One type of limestone aggregate and one penetration-graded asphalt cement (75-100) were used. Three concentrations of rubber and plastic (i.e. 5%, 10% and 20% of the total weight of asphalt cement), three rubber particle sizes (i.e. No. 4 [4.75mm] - 20 [0.85 mm], No. 20 [0.85mm] - 200 [0.075mm] and No. 4 [4.75mm] - 200 [0.075mm]) and one plastic particle size (i.e. No. 4 [4.75mm] - 10 [2.00mm]) were also used. It was found that while the addition of plastic significantly increased the strength of specimens, the addition of rubber decreased it. No. 4 [4.75mm] - 200 [0.075mm] rubber particles showed the best results with respect to the indirect tensile test. The Marshall stability and indirect tensile strength properties of plastic modified specimens increased. Marble powder and fly ash could be used as filler materials instead of stone powder in the asphalt concrete pavement specimens.

  15. Optimal formulations of some asphalt concrete roadway protective impregnation compositions

    Directory of Open Access Journals (Sweden)

    Yulia A. Ubas’kina

    2016-03-01

    Full Text Available The current paper describes optimization of the formulations of asphalt concrete roadway protective impregnation compositions based on BND 60/90 bitumen modified with petroleum resin. Physicochemical, technological and operating parameters of the prepared samples of the compositions are investigated.

  16. Steady-State Creep of Asphalt Concrete

    Directory of Open Access Journals (Sweden)

    Alibai Iskakbayev

    2017-02-01

    Full Text Available This paper reports the experimental investigation of the steady-state creep process for fine-grained asphalt concrete at a temperature of 20 ± 2 °С and under stress from 0.055 to 0.311 MPa under direct tension and was found to occur at a constant rate. The experimental results also determined the start, the end point, and the duration of the steady-state creep process. The dependence of these factors, in addition to the steady-state creep rate and viscosity of the asphalt concrete on stress is satisfactorily described by a power function. Furthermore, it showed that stress has a great impact on the specific characteristics of asphalt concrete: stress variation by one order causes their variation by 3–4.5 orders. The described relations are formulated for the steady-state of asphalt concrete in a complex stressed condition. The dependence is determined between stress intensity and strain rate intensity.

  17. Extending the Lifespan of Porous Asphalt Concrete

    NARCIS (Netherlands)

    Zhang, Y.

    2015-01-01

    Porous Asphalt (PA) concrete is widely used as a surfacing layer on highways in the Netherlands. The service life of PA wearing courses is limited because of the fact that it is vulnerable to raveling. The possibilities of applying preventive maintenance to PA wearing courses by means of spraying

  18. State-of-the-art and prospect for self-healing asphalt concrete

    Science.gov (United States)

    Xiao, Dong

    2017-08-01

    In order to solve the problem of asphalt concrete pavement cracks, this paper summarizes the principle of self-healing asphalt concrete, and describes asphalt concrete self-healing technology in various countries. This paper also analyses the factors of influencing the self-healing ability of asphalt concrete and the evaluation index, and describes the prospect of asphalt concrete self-healing technology.

  19. Performance evaluation of high modulus asphalt concrete mixes

    Science.gov (United States)

    Haritonovs, V.; Tihonovs, J.; Zaumanis, M.

    2016-04-01

    Dolomite is one of the most available sedimentary rocks in the territory of Latvia. Dolomite quarries contain about 1000 million tons of this material. However, according to Latvian Road Specifications, this dolomite cannot be used for average and high intensity roads because of its low quality (mainly, LA index). Therefore, mostly imported magmatic rocks (granite, diabase, gabbro, basalt) or imported dolomite are used which makes asphalt expensive. However, practical experience shows that even with these high quality materials roads exhibit rutting, fatigue and thermal cracks. The aim of the research is to develop a high performance asphalt concrete for base and binder courses using only locally available aggregates. In order to achieve resistance against deformations at a high ambient temperature, a hard grade binder was used. Workability, fatigue and thermal cracking resistance, as well as sufficient water resistance is achieved by low porosity (3-5%) and higher binder content compared to traditional asphalt mixtures. The design of the asphalt includes a combination of empirical and performance based tests, which in laboratory circumstances allow simulating traffic and environmental loads. High performance AC 16 base asphalt concrete was created using local dolomite aggregate with polymer modified (PMB 10/40-65) and hard grade (B20/30) bitumen. The mixtures were specified based on fundamental properties in accordance to EN 13108-1 standard.

  20. Polymer Blends Modified Asphalt

    Institute of Scientific and Technical Information of China (English)

    WANG YunPu; LI YuFeng; GAO XiaoHui; WANG RongMin

    2001-01-01

    @@ Asphalt is an important low-cost thermo-plastic material which is widely used for construction, in particular as road-paving. Therefore it is exposed to a wide range of load and weather conditions. Increasing traffic factors, such as heavier loads, higher traffic volume and higher tire pressure demand higher performance pavements. However, this kind of materials does not have good mechanical properties because it is hard and brittle in cold weather, and soft and fluid in a hot environment.

  1. 7 CFR 2902.36 - Concrete and asphalt release fluids.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Concrete and asphalt release fluids. 2902.36 Section... PROCUREMENT Designated Items § 2902.36 Concrete and asphalt release fluids. (a) Definition. Products that are designed to provide a lubricating barrier between the composite surface materials (e.g., concrete or...

  2. Polymer Blends Modified Asphalt

    Institute of Scientific and Technical Information of China (English)

    WANG; YunPu

    2001-01-01

    Asphalt is an important low-cost thermo-plastic material which is widely used for construction, in particular as road-paving. Therefore it is exposed to a wide range of load and weather conditions. Increasing traffic factors, such as heavier loads, higher traffic volume and higher tire pressure demand higher performance pavements. However, this kind of materials does not have good mechanical properties because it is hard and brittle in cold weather, and soft and fluid in a hot environment.  ……

  3. Evaluation of Asphalt Binder Modifiers

    Science.gov (United States)

    1990-01-01

    or SBS rubber described as an oil-extended polymer produced in pellet form. This type of rubber is available in other solid forms such as crumb or...is done to improve the performance characteristics of future pavements. Many research programs have been conducted on asphalt modifiers. Most of...tests were conducted during the second year of the study and resultant data were used to choose five materials to meet the test objectives of this

  4. An Improvement in Electrical Properties of Asphalt Concrete

    Institute of Scientific and Technical Information of China (English)

    WU Shao-peng; MO Lian-tong; SHUI Zhong-he; XUAN Dong-xing; XUE Yong-jie; YANG Wen-feng

    2002-01-01

    Materials such as Koch AH - 70, basalt aggregate, limestone powder and graphite particles were used to prepare conductive asphalt concrete, which is a new type of multi functional concrete. The mix proportion by weight was shown as follows. Fineaggregates (2.36-4.75 mm):fine aggregates (< 2.36mm): limestone powder: asphalt = 120:240: 14:30. The content of added graphite particles ranged from 0% to 20% ( by the Special weight of asphalt concerte). A conductive asphalt concrete with a resistivity around 10-103·Ωm was obtained.attention was paid to the effects of graphite content, graphite physical-chemical properties, asphalt content and temperature on the resistivity. Furthermore, an attempt was made to develop an electrically conductive model for asphalt concrete.

  5. Characterization of Failure and Permanent Deformation Behaviour of Asphalt Concrete

    NARCIS (Netherlands)

    Wang, J.G.

    2015-01-01

    Asphalt concrete is a viscoelastic material consisting of aggregates, filler and bitumen. The response of asphalt concrete is highly dependent on temperature, loading rate and confining pressure. Permanent deformation is one of the most important distresses developing during the flexible pavement

  6. Characterization of Failure and Permanent Deformation Behaviour of Asphalt Concrete

    NARCIS (Netherlands)

    Wang, J.G.

    2015-01-01

    Asphalt concrete is a viscoelastic material consisting of aggregates, filler and bitumen. The response of asphalt concrete is highly dependent on temperature, loading rate and confining pressure. Permanent deformation is one of the most important distresses developing during the flexible pavement se

  7. Low permeability asphalt concrete gamma ray shielding properties.

    Science.gov (United States)

    Binney, S E; Sykes, K L

    1997-01-01

    Energy-dependent gamma ray shielding properties were measured as a function of gamma ray energy for a low permeability asphalt concrete that is used as a cap to prevent water infiltration into radioactive waste sites. Experimental data were compared to ISO-PC point kernel shielding calculations. Calculated dose equivalent rates compared well with experimental values, especially considering the poor detector resolution involved. The shielding properties of the asphalt concrete closely resembled those of aluminum. The results presented can be used to determine the asphalt concrete thickness required to reduce dose equivalent rates from several gamma ray emitting radionuclides.

  8. 40 CFR 443.20 - Applicability; description of the asphalt concrete subcategory.

    Science.gov (United States)

    2010-07-01

    ... asphalt concrete subcategory. 443.20 Section 443.20 Protection of Environment ENVIRONMENTAL PROTECTION... MATERIALS (TARS AND ASPHALT) POINT SOURCE CATEGORY Asphalt Concrete Subcategory § 443.20 Applicability; description of the asphalt concrete subcategory. The provisions of this subpart are applicable to...

  9. Crack repair of asphalt concrete with induction energy

    NARCIS (Netherlands)

    García, A.; Schlangen, E.; Ven, M. van de; Vliet, D. van

    2011-01-01

    It is well known that the healing rates of asphalt courses increase with the temperature. A new method, induction heating, is used in this paper to increase the lifetime of asphalt concrete pavements. Mastic will be first made electrically conductive by the addition of conductive fibers. Then it wil

  10. Crack repair of asphalt concrete with induction energy

    NARCIS (Netherlands)

    García, A.; Schlangen, E.; Van de Ven, M.; Van Vliet, D.

    It is well known that the healing rates of asphalt courses increase with the temperature. A new method, induction heating, is used in this paper to increase the lifetime of asphalt concrete pavements. Mastic will be first made electrically conductive by the addition of conductive fibers. Then it wil

  11. About the sizes of elastomer particles in the asphalt concrete binder providing the maximum service life of pavements

    Science.gov (United States)

    Kaplan, A. M.; Chekunaev, N. I.

    2014-05-01

    It is noted that the durability of asphalt concrete pavements is determined by the time of the trunk cracks formation in the polymer-containing composites - in the modified by elastomers (e.g., by rubber) bitumenous binder of asphalt. Developed by the authors previously the theory of the cracks propagation in heterosystems [1] has allowed to investigate the problem of the cracks propagation in the rubber-bitumen composite. This investigations show that most effectively to prevente the trunk cracks formation in asphalt concrete can ultrafine rubber particles (150-750 nm) in a bitumenos binder of asphalt.

  12. DURABILITY OF ASPHALT CONCRETE MIXTURES USING DOLOMITE AGGREGATES

    Directory of Open Access Journals (Sweden)

    Imad Al-Shalout

    2015-12-01

    Full Text Available This study deals with the durability of asphalt concrete, including the effects of different gradations, compaction temperatures and immersion time on the durability potential of mixtures. The specific objectives of this study are: to investigate the effect of compaction temperature on the mechanical properties of asphalt concrete mixtures; investigate the effect of bitumen content and different aggregate gradations on the durability potential of bituminous mixtures.

  13. Resistivity-temperature Characteristics of Conductive Asphalt Concrete

    Institute of Scientific and Technical Information of China (English)

    SUN Wenzhou; LI Xu; YANG Qun; ZHANG Hongwei

    2016-01-01

    The changes of resistivity of conductive asphalt concrete at different temperatures were studied, and positive temperature coefficient (PTC) model was established to estimate the influence of temperature on the resistivity quantitatively, which eliminated the interference with conductivity evaluation brought by temperature variation. Finally, the analysis of temperature cycling test results proves that the changes of percolation network structure caused by temperature variation prompt the emergence of PTC of conductive asphalt concrete.

  14. Induction Healing of Porous Asphalt Concrete

    NARCIS (Netherlands)

    Liu, Q.

    2012-01-01

    Porous asphalt shows excellent performance in both noise reduction and water drainage. Although porous asphalt has these great qualities, its service life is much shorter (sometimes only half) compared to dense graded asphalt roads. Ravelling, which is the loss of aggregate particles from the surfac

  15. Induction Healing of Porous Asphalt Concrete

    NARCIS (Netherlands)

    Liu, Q.

    2012-01-01

    Porous asphalt shows excellent performance in both noise reduction and water drainage. Although porous asphalt has these great qualities, its service life is much shorter (sometimes only half) compared to dense graded asphalt roads. Ravelling, which is the loss of aggregate particles from the

  16. Performance of Recycled Asphalt Pavement as Coarse Aggregate in Concrete

    Directory of Open Access Journals (Sweden)

    Fidelis O. OKAFOR

    2010-12-01

    Full Text Available Recycled asphalt pavement (RAP is the reclaimed and reprocessed pavement material containing asphalt and aggregate. Most RAP is recycled back into pavements, and as a result there is a general lack of data pertaining to the mechanical properties for RAP in other possible applications such as Portland cement concrete. In the present study, some mechanical properties of Portland cement concrete containing RAP as coarse aggregate were investigated in the laboratory. Six concrete mixes of widely differing water/cement ratios and mix proportions were made using RAP as coarse aggregate. The properties tested include the physical properties of the RAP aggregate, the compressive and flexural strengths of the concrete. These properties were compared with those of similar concretes made with natural gravel aggregate. Results of the tests suggest that the strength of concrete made from RAP is dependent on the bond strength of the “asphalt-mortar” (asphalt binder-sand-filler matrix coatings on the aggregates and may not produce concrete with compressive strength above 25 MPa. However, for middle and low strength concrete, the material was found to compare favorably with natural gravel aggregate.

  17. Properties of Direct Coal Liquefaction Residue Modified Asphalt Mixture

    Directory of Open Access Journals (Sweden)

    Jie Ji

    2017-01-01

    Full Text Available The objectives of this paper are to use Direct Coal Liquefaction Residue (DLCR to modify the asphalt binders and mixtures and to evaluate the performance of modified asphalt mixtures. The dynamic modulus and phase angle of DCLR and DCLR-composite modified asphalt mixture were analyzed, and the viscoelastic properties of these modified asphalt mixtures were compared to the base asphalt binder SK-90 and Styrene-Butadiene-Styrene (SBS modified asphalt mixtures. The master curves of the asphalt mixtures were shown, and dynamic and viscoelastic behaviors of asphalt mixtures were described using the Christensen-Anderson-Marasteanu (CAM model. The test results show that the dynamic moduli of DCLR and DCLR-composite asphalt mixtures are higher than those of the SK-90 and SBS modified asphalt mixtures. Based on the viscoelastic parameters of CAM models of the asphalt mixtures, the high- and low-temperature performance of DLCR and DCLR-composite modified asphalt mixtures are obviously better than the SK-90 and SBS modified asphalt mixtures. In addition, the DCLR and DCLR-composite modified asphalt mixtures are more insensitive to the frequency compared to SK-90 and SBS modified asphalt mixtures.

  18. Network morphology of straight and polymer modified asphalt cements.

    Science.gov (United States)

    Rozeveld, S J; Shin, E E; Bhurke, A; France, L; Drzal, L T

    1997-09-01

    Asphalt cements are often regarded as a colloidal system containing several hydrocarbon constituents: asphaltenes, resins, and oils. The high molecular weight asphaltene particles are considered to be covered in a sheath of resins and dispersed in the lower molecular weight oily medium [Whiteoak (1990) The Shell Bitumen Handbook (Shell Bitumen UK, Riversdell House, Surrey, UK)]. However, the exact arrangement of the asphaltene particles within the oily phase will vary depending on the relative amounts of resin, asphaltene, and oils. It is this arrangement and the degree of association between asphaltene particles that govern the rheological properties of the cement [Simpson et al. (1961) J. Chem. Eng. Data 6:426-429; Whiteoak (1990)]. Here we report for the first time the observation of a three-dimensional network of asphaltene strands within straight, polymer-modified, and aged asphalt cements. While the existence of a asphaltene/resin micelle network has been proposed in previous studies [Whiteoak (1990)], direct observation has not been reported. The network is expected to greatly influence the rheological properties of the asphalt binder and ultimately the properties of asphalt concretes. In situ fracture studies of asphalt cement/aggregate composites indicate a possible correlation between the network structure and adhesion between the cement binder and aggregate.

  19. Performance Evaluation of Stone Mastic Asphalt and Hot Mix Asphalt Mixtures Containing Recycled Concrete Aggregate

    Directory of Open Access Journals (Sweden)

    Mohammad Saeed Pourtahmasb

    2014-01-01

    Full Text Available Environmental and economic considerations have encouraged civil engineers to find ways to reuse recycled materials in new constructions. The current paper presents an experimental research on the possibility of utilizing recycled concrete aggregates (RCA in stone mastic asphalt (SMA and hot mix asphalt (HMA mixtures. Three categories of RCA in various percentages were mixed with virgin granite aggregates to produce SMA and HMA specimens. The obtained results indicated that, regardless of the RCA particular sizes, the use of RCA to replace virgin aggregates increased the needed binder content in the asphalt mixtures. Moreover, it was found that even though the volumetric and mechanical properties of the asphalt mixtures are highly affected by the sizes and percentages of the RCA but, based on the demands of the project and traffic volume, utilizing specific amounts of RCA in both types of mixtures could easily satisfy the standard requirements.

  20. Research on fracture performance of epoxy asphalt concrete based on double-K fracture criterion

    Science.gov (United States)

    Zhang, M.; Qian, Z. D.; Xue, Y. C.

    2017-01-01

    After cracks appear on steel bridge deck epoxy asphalt concrete pavement, cracks propagate fast under vehicle load. This paper studied the fracture performance of epoxy asphalt concrete, utilized single edge notched beam (SEB) three-point bending test, measured the load (P) exerted on epoxy asphalt SEB; utilized digital camera to record the fracture process of epoxy asphalt SEB, extracted the images according to the required sampling frequency and utilized Image-Pro Plus to measure the crack mouth opening displacement (CMOD) of epoxy asphalt SEB on the extracted images; calculated the double-K fracture parameters according to the P-CMOD curve. Results indicate that of epoxy asphalt concrete is 1.11 MPa and of epoxy asphalt concrete is 2.31 MPa at -15°C of epoxy asphalt concrete is 1.02 MPa and of epoxy asphalt concrete is 1.83 MPa at -5°C of epoxy asphalt concrete is 0.77 MPa and of epoxy asphalt concrete is 1.82 MPa at 5°C. The double-K fracture parameters of epoxy asphalt concrete increase slightly when the temperature decreases at the scope of -15°C to 5°C. The relation of and is .

  1. ASSESSMENT OF THE PROPERTIES OF ASPHALT MODIFIED WITH USED TIRES

    Directory of Open Access Journals (Sweden)

    Olufikayo Aderinlewo

    2017-04-01

    Full Text Available This study investigates the properties of asphalt mix modified with ground tire. The ground tire was introduced into the asphalt in a melted form at varying percentages of 2%, 4%, 6%, 8% and 10% by weight of the asphalt. The properties of the asphalt mixed with the ground tire were then obtained through penetration, softening point, flash and fire point and ductility tests. These properties were then compared with those of the control asphalt to determine the effectiveness of the ground tire in improving the asphalt properties. The results showed that the ground tire additive improved the asphalt properties considerably.

  2. The Study of Water Stability for SBS and Polyacrylate Composite Modified Asphalt Mixture

    Directory of Open Access Journals (Sweden)

    HU Qiusheng

    2014-09-01

    Full Text Available Polyacrylate (Polyacrylate, called PAE is a kind of thermoplastic polymer latex, which is easy to form a waterproof membrane and has greater adhesion ,always be used in concrete to enhance its ability to resist water corrosion.SBS is an inorganic modifier for modified asphalt mixture will help to improve the high and low temperature stability and other road performance, ect.However,its ability to enhanced asphalt mixture’s resistance for water damage is not obvious. In order to research the two composite modified asphalt mixture’s resistance effects to water damage , the Marshall Stability Test and Fort Kentucky Flooding Scattering Experiments were used on asphalt mixtures, SBS modified asphalt mixture and composite modified asphalt mixture and the effect of different composite modified PAE content were studied. The results showed that: PAE can significantly improve the water stability of asphalt mixture, what’s more, with the increase use of PAE,the mass loss rate of asphalt mixture decreases steadily.

  3. Effect of Material Composition and Environmental Condition on Thermal Characteristics of Conductive Asphalt Concrete.

    Science.gov (United States)

    Pan, Pan; Wu, Shaopeng; Hu, Xiaodi; Liu, Gang; Li, Bo

    2017-02-23

    Conductive asphalt concrete with high thermal conductivity has been proposed to improve the solar energy collection and snow melting efficiencies of asphalt solar collector (ASC). This paper aims to provide some insight into choosing the basic materials for preparation of conductive asphalt concrete, as well as determining the evolution of thermal characteristics affected by environmental factors. The thermal properties of conductive asphalt concrete were studied by the Thermal Constants Analyzer. Experimental results showed that aggregate and conductive filler have a significant effect on the thermal properties of asphalt concrete, while the effect of asphalt binder was not evident due to its low proportion. Utilization of mineral aggregate and conductive filler with higher thermal conductivity is an efficient method to prepare conductive asphalt concrete. Moreover, change in thermal properties of asphalt concrete under different temperature and moisture conditions should be taken into account to determine the actual thermal properties of asphalt concrete. There was no noticeable difference in thermal properties of asphalt concrete before and after aging. Furthermore, freezing-thawing cycles strongly affect the thermal properties of conductive asphalt concrete, due to volume expansion and bonding degradation.

  4. Effect of Material Composition and Environmental Condition on Thermal Characteristics of Conductive Asphalt Concrete

    Directory of Open Access Journals (Sweden)

    Pan Pan

    2017-02-01

    Full Text Available Conductive asphalt concrete with high thermal conductivity has been proposed to improve the solar energy collection and snow melting efficiencies of asphalt solar collector (ASC. This paper aims to provide some insight into choosing the basic materials for preparation of conductive asphalt concrete, as well as determining the evolution of thermal characteristics affected by environmental factors. The thermal properties of conductive asphalt concrete were studied by the Thermal Constants Analyzer. Experimental results showed that aggregate and conductive filler have a significant effect on the thermal properties of asphalt concrete, while the effect of asphalt binder was not evident due to its low proportion. Utilization of mineral aggregate and conductive filler with higher thermal conductivity is an efficient method to prepare conductive asphalt concrete. Moreover, change in thermal properties of asphalt concrete under different temperature and moisture conditions should be taken into account to determine the actual thermal properties of asphalt concrete. There was no noticeable difference in thermal properties of asphalt concrete before and after aging. Furthermore, freezing–thawing cycles strongly affect the thermal properties of conductive asphalt concrete, due to volume expansion and bonding degradation.

  5. Modified Asphalt Binder with Natural Zeolite for Warm Mix Asphalt

    Directory of Open Access Journals (Sweden)

    Dubravský Marián

    2015-11-01

    Full Text Available In recent years, warm mix asphalt (WMA is becoming more and more used in the asphalt industry. WMA provide a whole range of benefits, whether economic, environmental and ecological. Lower energy consumption and less pollution is the most advantages of this asphalt mixture. The paper deals with the addition of natural zeolite into the sub base asphalt layers, which is the essential constituent in the construction of the road. Measurement is focused on basic physic – mechanical properties declared according to the catalog data sheets. The aim of this article is to demonstrate the ability of addition the natural zeolite into the all asphalt layers of asphalt pavement. All asphalt mixtures were compared with reference asphalt mixture, which was prepared in reference temperature.

  6. Possibilities of preparation asphalt concrete by oil sands of Kazakhstan

    Directory of Open Access Journals (Sweden)

    Erbol Tileuberdi

    2012-12-01

    Full Text Available In the paper physicochemical properties of oil sands of Munayli-Mola deposits and efficient ways to use them for preparing asphalt concrete were represented. For determination of organic part of oil sands the extraction methods were used in Soxhlet apparatus by variety of solvents. It has been established 16 wt.% content of natural bitumen in oil sands, which compared with results of ash content determination. According to results of experiment, the natural bitumen is heavy oil and its characteristics close to characteristics of paving bitumen. The optimum content of oil sands in asphalt mix are 28 and 47 mass %, the mixes prepared under these conditions satisfy standard requirements of the Republic of Kazakhstan on the asphalt mixture ST RK 1225-2003.

  7. Effects of SBS Content on the Performance of Modified Asphalt

    Science.gov (United States)

    Zhuang, Chuanyi; Li, Ning; Zhao, Wei; Cai, Chuanfeng

    2017-06-01

    The effects of different dosage SBS (Styrene-butadiene-styrene) modifiers on the properties of asphalt were compared and analyzed from the temperature sensitivity, high temperature performance and low temperature performance of modified asphalt. The results show that with the increase of the content of SBS modifier, the softening point and kinematic viscosity of SBS modified asphalt are increased and the high temperature performance is improved. The low temperature ductility is improved; the penetration of modified asphalt is reduced, the temperature sensitivity of the asphalt is reduced. However, when the content of modifier is more than 4%, the penetration index of SBS modified asphalt decreases linearly with the increase of the content of modifier, and the temperature sensitivity increases. The engineering application should be determined according to the specific technical requirements.

  8. The Effect of High RAP and High Asphalt Binder Content on the Dynamic Modulus and Fatigue Resistance of Asphalt Concrete

    OpenAIRE

    Tomlinson, Christopher

    2013-01-01

    This thesis investigates the effects of using various percentages of RAP and asphalt binder contents on the dynamic modulus and fatigue resistance of asphalt concrete. Two RAP percentages (20% and 40%) and three binder percentages (plant-mixed, plant-mixed + 0.5%, and plant-mixed + 1.0%) were evaluated. A Superpave gyratory compactor and an asphalt vibratory compactor were used to prepare dynamic modulus samples and fatigue beam samples at 7% air voids. Three replicate samples for each percen...

  9. Possibilities of preparation asphalt concrete by oil sands of Kazakhstan

    OpenAIRE

    Erbol Tileuberdi; Yerdos Ongarbayev; F. Behrendt; Schneider, I.; Yerzhan Imanbayev; B. Tuleutayev; Yerlan Doszhanov; Zulkhair Mansurov

    2012-01-01

    In the paper physicochemical properties of oil sands of Munayli-Mola deposits and efficient ways to use them for preparing asphalt concrete were represented. For determination of organic part of oil sands the extraction methods were used in Soxhlet apparatus by variety of solvents. It has been established 16 wt.% content of natural bitumen in oil sands, which compared with results of ash content determination. According to results of experiment, the natural bitumen is heavy oil and its charac...

  10. Criteria for asphalt-rubber concrete in civil airport pavements: Mixture design

    Science.gov (United States)

    Roberts, F. L.; Lytton, R. L.; Hoyt, D.

    1986-07-01

    A mixture design procedure is developed to allow the use of asphalt-rubber binders in concrete for flexible airport pavement. The asphalt-rubber is produced by reacting asphalt with ground, scrap tire rubber to produce the binder for the asphalt-rubber concrete. Procedures for laboratory preparation of alsphalt-rubber binders using an equipment setup that was found by researchers to produce laboratory binders with similar properties to field processes are included. The rubber-asphalt concrete mixture design procedure includes adjustments to the aggregate gradation to permit space for the rubber particles in the asphalt-rubber binder as well as suggested mixing and compaction temperatures, and compaction efforts. While the procedure was used in the laboratory to successfully produce asphalt-rubber concrete mixtures, it should be evaluated in the field to ensure that consistent results can be achieved in a production environment.

  11. Mechanical properties of gutta-percha sulfide modified asphalt

    Science.gov (United States)

    Zou, X. Y.; Gu, X. Y.; Wang, X. W.

    2017-01-01

    Gutta-percha is the isomer of caoutchouc and can be used to enhance the performance of asphalt. In this paper, the produce proceedings of gutta-percha sulfide and gutta-percha sulfide modified asphalt are introduced. The performance indices of gutta-percha sulfide modified asphalt samples with different proportions are examined based on laboratory tests and the optimum ratio of gutta-percha and sulfur is decided.The micromechanism, temperature sensitivity, high and low temperature properties and viscoelasticity of the polymer modified asphalt are analyzed to discuss the modified mechanism and to decide the optimal polymer content. Low temperature bending tests are carried out to verify the low temperature performance of gutta-percha sulfide modified asphalt mixture. Research results showed that gutta-percha sulfide modified asphalt has good low temperature performance and a promising application prospect in the cold regions.

  12. Bone Glue Modified Asphalt: A Step towards Energy Conservation and Environment Friendly Modified Asphalts.

    Science.gov (United States)

    Rizvi, Hashim Raza; Khattak, Mohammad Jamal; Gallo, August A

    2014-01-01

    Asphalt has been modified for the past several decades using various additives, including synthetic polymers. Polymer modification improves structural and engineering characteristics of the binder, which is a result of improvement in rheological characteristics of binder as well as its adhesion capability with the aggregate. Such enhancement inevitably enhances the performance characteristics of hot mix asphalts (HMA) such as fatigue life, resistance to rutting, and thermal cracking. Even though polymer-modified HMA is popular in North America and European countries, its use is still limited in developing countries of Southeast Asia due to high costs associated with its manufacturing, processing, and energy consumption. In this study, a new kind of asphalt modifier derived from animal wastes, such as bones, hides, and flesh commonly known as Bone Glue, is studied. This biomaterial which is a by-product of food and cattle industries is cheap, conveniently available, and produced locally in developing countries. The results of the research study showed that the bone glue can easily be mixed with asphalt without significantly altering the asphalt binder's viscosity and mixing and compaction temperatures of HMA. Additionally, improvements in complex shear modulus for a range of temperatures were also determined and it was found that complex shear modulus was improved by bone glue modification.

  13. Specifications and Construction Methods for Asphalt Concrete and Other Plant-Mix Types, 3rd Edition.

    Science.gov (United States)

    Asphalt Inst., College Park, MD.

    The purpose of this publication is to assist engineers in the analysis, design and control of paving projects that use asphalt concrete and other asphalt plant-mixes. The scope of this new third edition has been enlarged, and changes necessitated by advances in asphalt technology have been incorporated. Chapters I and II and Appendices A and B…

  14. EFFECTS OF STYRENE-BUTADIENE-STYRENE ON STIFFNESS OF ASPHALT CONCRETE AT DIFFERENT TRAFFIC CONDITIONS

    Directory of Open Access Journals (Sweden)

    GHOLAMALI SHAFABAKHSH

    2016-04-01

    Full Text Available The previous studies have explored the effects of Styrene-Butadiene-Styrene (SBS as the most prevalent modifier for asphalt mixtures. The current study intends to compare stiffness modulus of control and SBS modified asphalt mixtures under different traffic loadings. To this end, resilient modulus tests were performed on both conventional and SBS modified specimens. Tests were conducted at 5, 25 and 40°C with loading times of 50, 100, 300, 600 and 1000 milliseconds and 4, 9 and 30 as ratio of rest periods (between loading pulses to loading times (R/L. Using these test parameters and haversine and square loading pulses that represent vertical stress distribution at different depths within an asphalt layer, a variety of traffic densities and vehicle speeds were simulated and their effects on stiffness of asphalt concrete were determined. Results indicated that SBS modification provide higher stiffness under haversine pulse with long loading time at 40°C, so that it was about 3 times of unmodified mixture stiffness. The effect of traffic density that represented by R/L was significant only in long loading time (1000 ms especially under haversine pulse.

  15. Evaluation of Colemanite Waste as Aggregate Hot Mix Asphalt Concrete

    Directory of Open Access Journals (Sweden)

    Nihat MOROVA

    2015-09-01

    Full Text Available In this study usability of waste colemanite which is obtained after cutting block colemanite for giving proper shape to blocks as an aggregate in hot mix asphalt. For this aim asphalt concrete samples were prepared with four different aggregate groups and optimum bitumen content was determined. First of all only limestone was used as an aggregate. After that, only colemanite aggregate was used with same aggregate gradation. Then, the next step of the study, Marshall samples were produced by changing coarse and fine aggregate gradation as limestone and colemanite and Marshall test were conducted. When evaluated the results samples which produced with only limestone aggregate gave the maximum Marshall Stability value. When handled other mixture groups (Only colemanite, colemanite as coarse aggregate-limestone as fine aggregate, colemanite as fine aggregate-limestone as coarse aggregate all groups were verified specification limits. As a result, especially in areas where there is widespread colemanite waste, if transportation costs did not exceed the cost of limestone, colemanite stone waste could be used instead of limestone in asphalt concrete mixtures as fine aggregate

  16. Creep Characteristics of Crumb Rubber Modified Asphalt Binder

    Institute of Scientific and Technical Information of China (English)

    WANG Lan; CHANG Chunqing; XING Yongming

    2011-01-01

    Crumb rubber modified asphalt containing 20 percent crumb rubber particles of 30mesh has been examined by Scanning Electron Microscope (SEM) to observe the microcosmic appearance and the characteristic distribution of crumb rubber particles in asphalt. The SEM pictures reveal that the crumb rubber particles distribute evenly in the asphalt and they are compatible well with asphalt. The shear creep test of crumb rubber modified asphalt was carried out at - 10 ℃ and 40 ℃ by Dynamic Shear Rheology (DSR). The shearing deformation at different temperature and creep stiffness modulus curve at loading stage of crumb rubber modified asphalt have been measured. The stiffness modulus of crumb rubber modified asphalt is much temperature sensitive and it decays much quick at the early stage of loading than normal asphalt. The rate of decay of stiffness modulus is slow at the subsequent stage and stiffness modulus approaches to a stable value at the final stage at a higher temperature. In addition, Burgers model is suitable to describe and simulate experimental results of viscoelastic properties of the crumb rubber modified asphalt.

  17. Thermal Properties of Asphalt Mixtures Modified with Conductive Fillers

    Directory of Open Access Journals (Sweden)

    Byong Chol Bai

    2015-01-01

    Full Text Available This paper investigates the thermal properties of asphalt mixtures modified with conductive fillers used for snow melting and solar harvesting pavements. Two different mixing processes were adopted to mold asphalt mixtures, dry- and wet-mixing, and two conductive fillers were used in this study, graphite and carbon black. The thermal conductivity was compared to investigate the effects of asphalt mixture preparing methods, the quantity, and the distribution of conductive filler on thermal properties. The combination of conductive filler with carbon fiber in asphalt mixture was evaluated. Also, rheological properties of modified asphalt binders with conductive fillers were measured using dynamic shear rheometer and bending beam rheometer at grade-specific temperatures. Based on rheological testing, the conductive fillers improve rutting resistance and decrease thermal cracking resistance. Thermal testing indicated that graphite and carbon black improve the thermal properties of asphalt mixes and the combined conductive fillers are more effective than the single filler.

  18. Durable high strength cement concrete topping for asphalt roads

    Science.gov (United States)

    Vyrozhemskyi, Valerii; Krayushkina, Kateryna; Bidnenko, Nataliia

    2017-09-01

    Work on improving riding qualities of pavements by means of placing a thin cement layer with high roughness and strength properties on the existing asphalt pavement were conducted in Ukraine for the first time. Such pavement is called HPCM (High Performance Cementitious Material). This is a high-strength thin cement-layer pavement of 8-9 mm thickness reinforced with metal or polymer fiber of less than 5 mm length. Increased grip properties are caused by placement of stone material of 3-5 mm fraction on the concrete surface. As a result of the research, the preparation and placement technology of high-strength cement thin-layer pavement reinforced with fiber was developed to improve friction properties of existing asphalt pavements which ensures their roughness and durability. It must be emphasized that HPCM is a fundamentally new type of thin-layer pavement in which a rigid layer of 10 mm thickness is placed on a non-rigid base thereby improving riding qualities of asphalt pavement at any season of a year.

  19. Analysis of Load Stress for Asphalt Pavement of Lean Concrete Base

    Science.gov (United States)

    Lijun, Suo; Xinwu, Wang

    The study revealed that whether it is early distresses in asphalt pavement or not depends largely on working performance of base. In the field of asphalt pavement, it is widely accepted that lean concrete base, compared with the general semi-rigid base, has better working performance, such as high strength and good eroding resistance. Problem of early distresses in asphalt pavement, which caused by more traffic loadings, can be settled effectively when lean concrete is used in asphalt pavement. Traffic loading is important parameter used in the analysis of the new pavement design. However, few studies have done extensive and intensive research on the load stress for asphalt pavement of lean concrete base. Because of that, it is necessary to study the load stress for the asphalt pavement. In the paper, first of all, three-dimension finite element model of the asphalt pavement is created for the aim of doing mechanical analysis for the asphalt pavement. And then, the two main objectives of this study are investigated. One is analysis for load stress of lean concrete base, and the other is analysis for load stress of asphalt surface. The results show that load stress of lean concrete base decreases, decrease and increase with increase of base's thickness, surface's thickness and ratio of base's modulus to foundation's modulus respectively. So far as the asphalt surface is concerned, maximum shearing stress, which is caused by load, is evident in asphalt surface which is located in transverse contraction joint of lean concrete base of asphalt pavement. Maximum shearing stress decrease, decrease, decrease and increase respectively with increase of the surface's modulus, the surface's thickness, base's thickness and ratio of base's modulus to foundation's modulus.

  20. Evaluation of Aging Resistance of Graphene Oxide Modified Asphalt

    Directory of Open Access Journals (Sweden)

    Shaopeng Wu

    2017-07-01

    Full Text Available Graphene oxide (GO has a unique layered structure with excellent gas and liquid blocking properties. It is widely used in many areas, such as gas sensors, carbon-based electronics, impermeable membranes, and polymeric composite materials. In order to evaluate whether GO (1% and 3% by weight of asphalt can improve the aging resistance performance of the asphalt, 80/100 penetration grade asphalt (90 A and styrene–butadiene–styrene modified asphalt (SBS MA were used to prepare the GO modified asphalt by the melt blending method. The surface morphology of the GO was analyzed by scanning electron microscope (SEM. The UV aging test was conducted to simulate the aging during the service period. After UV aging test, the physical performances of GO-modified asphalts were tested, and the IC=O and IS=O increments were tested by Fourier transform infrared spectroscopy (FTIR to evaluate the aging resistance performance of the GO modified asphalt. In addition, the rheological properties of GO modified asphalts were studied using a dynamic shear rheometer (DSR. The SEM analysis indicated that the GO exhibits many shared edges, and no agglomeration phenomenon was found. With respect to the physical performance test, the FTIR and the DSR results show that GO can improve the UV aging resistance performance of 90 A and SBS MA. In addition, the analysis indicated that the improvement effect of 3% GO is better than the 1% GO. The testing on the rheological properties of the modified asphalt indicated that the GO can also improve the thermo-oxidative aging resistance performance of asphalt.

  1. Analysing polystyrene-modified asphalt and its incidence in a heat-dense asphalt mixture

    Directory of Open Access Journals (Sweden)

    Ana Sofía Figueroa Infante

    2010-04-01

    Full Text Available This article presents some results obtained with an MDC-2 asphalt/polystyrene-modified asphalt mixture as a result of crushing waste glass. The stone, asphalt and polystyrene materials’ were characterised for drawing up the design. The Marshal method was used for obtaining the best asphalt- stone-polystyrene percentages. The Superpave method was used for analysing the asphalt; the mixture’s dynamic behaviour was analysed using a test involving 20ºC and 30ºC trapezoidal fatigue for 90x10-6, 150x10-6 and 220x10-6m deformation. The truck-wheel test was analysed for a 13-ton load, similar to that of the heaviest axle on a Transmilenio (articulated bus. The dynamic module test was analysed for 15ºC, 20ºC and 30ºC and 2.5, 5 and 10 Hz frequencies. Conventional asphalt mixture and modified asphalt results were contrasted, interesting behaviour being observed regarding plastic deformation of the modified mixture in service

  2. Epoxy asphalt concrete paving on the deck of long-span steel bridges

    Institute of Scientific and Technical Information of China (English)

    HUANG Wei; QIAN Zhendong; CHEN Gang; YANG Jun

    2003-01-01

    It is the first systematic research in the world on the composition design of epoxy asphalt concrete as pav- ing material. Material characteristics and service perform- ance of mixture, fatigue resistance characteristics of epoxy asphalt concrete by the fatigue test of complex beam have also been described. This research indicates that epoxy asphalt concrete is a good type of paving material. Research results have been applied successfully in the paving of steel deck of the Second Nanjing Yangtze River Bridge (SNYRB). It provides a new paving type for long-span steel bridges of China and has a bright application prospect.

  3. Dynamic response of concrete pavement structure with asphalt isolating layer under moving loads

    Directory of Open Access Journals (Sweden)

    Jianmin Wu

    2014-12-01

    Full Text Available A three-dimensional finite element model (3D FEM is built using ABAQUS to analyze the dynamic response of a concrete pavement structure with an asphalt isolating layer under moving loads. The 3D model is prepared and validated in the state of no asphalt isolating layer. Stress and deflection at the critical load position are calculated by changing thickness, modulus of isolating layer and the combination between the isolating layer and concrete slab. Analysis result shows that the stress and deflection of the concrete slab increase with the increase of thickness. The stress and deflection of the concrete slab decrease with the increase of combination between the isolating layer and concrete slab. The influence of changing the isolating layer modulus to the stress and deflection of the concrete slab is not significant. From the results, asphalt isolating layer design is suggested in concrete pavement.

  4. Damage detection and artificial healing of asphalt concrete after trafficking with a load simulator

    Science.gov (United States)

    Bueno, M.; Arraigada, M.; Partl, M. N.

    2016-08-01

    Artificial healing of asphalt concrete by induction heating requires the addition of electrically conductive and/or magnetic materials into the asphalt mixture. Hence, bitumen can be heated up by an alternating electromagnetic field, decreasing therefore its viscosity and allowing it to flow for closing cracks and recover bonding among the mineral aggregates.

  5. Evaluation of Warm Mix Asphalt Additives for Use in Modified Asphalt Mixtures

    Science.gov (United States)

    Chamoun, Zahi

    The objective of this research effort is to evaluate the use of warm-mix additives with polymer modified and terminal blend tire rubber asphalt mixtures from Nevada and California. The research completed over two stages: first stage evaluated two different WMA technologies; Sasobit and Advera, and second stage evaluated one additional WMA technology; Evotherm. The experimental program covered the evaluation of resistance of the mixtures to moisture damage, the performance characteristics of the mixtures, and mechanistic analysis of mixtures in simulated pavements. In the both stages, the mixture resistance to moisture damage was evaluated using the indirect tensile test and the dynamic modulus at multiple freeze-thaw cycles, and the resistance of the various asphalt mixtures to permanent deformation using the Asphalt Mixture Performance Tester (AMPT). Resistance of the untreated mixes to fatigue cracking using the flexural beam fatigue was only completed for the first stage. One source of aggregates was sampled in, two different batches, three warm mix asphalt technologies (Advera, Sasobit and Evotherm) and three asphalt binder types (neat, polymer-modified, and terminal blend tire rubber modified asphalt binders) typically used in Nevada and California were evaluated in this study. This thesis presents the resistance of the first stage mixtures to permanent deformation and fatigue cracking using two warm-mix additives; Advera and Sasobit, and the resistance to moisture damage and permanent deformation of the second stage mixtures with only one warm-mix additive; Evotherm.

  6. Recycling of polyethylene terephthalate (PET plastic bottle wastes in bituminous asphaltic concrete

    Directory of Open Access Journals (Sweden)

    Adebayo Olatunbosun Sojobi

    2016-12-01

    Full Text Available This research sheds light on the concept of eco-friendly road construction which comprises eco-design, eco-extraction, eco-manufacturing, eco-construction, eco-rehabilitation, eco-maintenance, eco-demolition, and socioeconomic empowerment. It also revealed the challenges being faced in its adoption and the benefits derivable from its application. Furthermore, the effects of recycling PET plastic bottle wastes produced in North Central Nigeria in bituminous asphaltic concrete (BAC used in flexible pavement construction were also evaluated. The mix design consists of 60/70 penetration-grade asphaltic concrete (5%, 68% coarse aggregate, 6% fine aggregate, and 21% filler using the dry process at 170°C. The optimum bitumen content (OBC for conventional BAC was obtained as 4% by weight of total aggregates and filler. Polymer-coated aggregate (PCA-modified BAC seems preferable because it has the potential to utilize more plastic wastes with a higher optimum plastic content (OPC of 16.7% by weight of total aggregates and filler compared to that of 9% by weight of OBC achieved by PMB-BAC. For both PMB- and PCA-modified BAC, an increase in air void, void in mineral aggregate, and Marshall stability were observed. Eco-friendly road construction which recycles PET wastes should be encouraged by government considering its potential environmental and economic benefits.

  7. Use of rubber crumb for preparation of asphalt-concrete mixtures

    Directory of Open Access Journals (Sweden)

    Yerbol Tileuberdi

    2012-03-01

    Full Text Available In this article use of rubber crumb from spent tire for preparation of rubber-bitumen compounds is investigated. Then the rubber-bitumen compositions are used in composition of asphalt concrete mixes .

  8. Use of rubber crumb for preparation of asphalt-concrete mixtures

    OpenAIRE

    Yerbol Tileuberdi; S. Kozbakarova; Yerdos Ongarbayev; B. Tuleutaev; Zulkhair Mansurov

    2012-01-01

    In this article use of rubber crumb from spent tire for preparation of rubber-bitumen compounds is investigated. Then the rubber-bitumen compositions are used in composition of asphalt concrete mixes .

  9. Size-dependent enrichment of waste slag aggregate fragments abraded from asphalt concrete.

    Science.gov (United States)

    Takahashi, Fumitake; Shimaoka, Takayuki; Gardner, Kevin; Kida, Akiko

    2011-10-30

    Authors consider the environmental prospects of using melted waste slag as the aggregate for asphalt pavement. In particular, the enrichment of slag-derived fragments in fine abrasion dust particles originated from slag asphalt concrete and its size dependency were concerned. A series of surface abrasion tests for asphalt concrete specimens, containing only natural aggregates as reference or 30 wt% of substituted slag aggregates, were performed. Although two of three slag-asphalt concretes generated 1.5-3.0 times larger amount of abrasion dust than the reference asphalt concrete did, it could not be explained only by abrasion resistance of slag. The enrichment of slag-derived fragments in abrasion dust, estimated on the basis of the peak intensity of quartz and heavy metal concentrations, had size dependency for all slag-asphalt concretes. Slag-derived fragments were enriched in abrasion dust particles with diameters of 150-1000 μm. Enrichment factors were 1.4-2.1. In contrast, there was no enrichment in abrasion dust particles with diameter less than 75 μm. This suggests that prior airborne-size fragmentation of substituted slag aggregates does not need to be considered for tested slag aggregates when environmental risks of abrasion dust of slag-asphalt pavement are assessed.

  10. Investigation on Reinforced Mechanism of Fiber Reinforced Asphalt Concrete Based on Micromechanical Modeling

    Directory of Open Access Journals (Sweden)

    Ying Gao

    2017-01-01

    Full Text Available Short fibers have been widely used to prepare the fiber reinforced asphalt concrete (FRAC. However, internal interactions between fiber and other phases of asphalt concrete are unclear although experimental methods have been used to design the FRAC successfully. In this paper, numerical method was used to investigate the reinforced mechanism of FRAC from microperspective. 2D micromechanical model of FRAC was established based on Monte Carlo theory. Effects of fiber length and content on stress state of asphalt mortar, effective modulus, and viscoelastic deformation of asphalt concrete were investigated. Indirect tensile stiffness modulus (ITSM test and uniaxial creep test were carried out to verify the numerical results. Results show that maximum stress of asphalt mortar is lower compared to the control concrete when the fiber length is longer than 12 mm. Fiber reduces the stress level of asphalt mortar significantly. Fiber length has no significant influence on the effective modulus of asphalt concrete. Fiber length and content both have notable impacts on the viscoelastic performance of FRAC. Fiber length should be given more attention in the future design of FRAC except the content.

  11. Influence of reclaimed asphalt with polymer modified bitumen on properties of different asphalts for a wearing course

    NARCIS (Netherlands)

    Komačka, J.; Remišová, E.; Liu, G.; Leegwater, G.; Nielsen, E.

    2014-01-01

    A laboratory investigation was performed to study the effect of reclaimed asphalt with polymer modified bitumen on the properties describing asphalt performance. Three types of asphalts used for wearing courses in Europe (SMA 11, AC 11 and PA 8) were investigated. Five combinations of reclaimed asph

  12. A multiscale model for predicting the viscoelastic properties of asphalt concrete

    Science.gov (United States)

    Garcia Cucalon, Lorena; Rahmani, Eisa; Little, Dallas N.; Allen, David H.

    2016-08-01

    It is well known that the accurate prediction of long term performance of asphalt concrete pavement requires modeling to account for viscoelasticity within the mastic. However, accounting for viscoelasticity can be costly when the material properties are measured at the scale of asphalt concrete. This is due to the fact that the material testing protocols must be performed recursively for each mixture considered for use in the final design.

  13. A STUDY OF FATIGUE LIFE OF ASPHALT CONCRETE BASED ON SHUNGITE MINERAL POWDER

    OpenAIRE

    D. I. Chernousov; Vl. P. Podolsky; E. V. Trufanov; B. A. Bondarev

    2011-01-01

    Problem statement. Shortage of mineral powder stimulates seeking of new materials and technologiesby which traditional ones can be replaced without deterioration of their operating properties. Thatis why a study of mineral powder from shungite and development of new technologies of arrangementof high quality and durable asphalt concrete pavement based on shungite is an actual problem.Results. Bearing capacity and service life of asphalt concrete pavement is most completely characterizedby mod...

  14. Assessment of the aging level of rejuvenated hot mixed asphalt concrete pavements

    Science.gov (United States)

    McGovern, Megan; Buttlar, William G.; Reis, Henrique

    2016-04-01

    The efficacy of asphalt rejuvenator on restoring the properties of oxidatively aged asphalt was tested via a non-collinear ultrasonic subsurface wave mixing technique modified for field use. Longitudinal transducers were mounted on angle wedges to generate subsurface dilatational waves to allow for pavement evaluation when there is only access to one side. Because in the field the asphalt concrete (AC) pavement properties (i.e., ultrasonic velocities and attenuations) are unknown, a pre-determined fixed incident angle (based on the AC mixture type) was used, which allows for practical implementation in the field. Oxidative aged AC specimens were coated with rejuvenator (10% by weight of the binder) and left to dwell for varying amounts of time. Once the dwell time reached the desired amount, the specimen was immediately ultrasonically tested. The frequency ratio, f2/f1, at which the interaction took place and the normalized nonlinear wave generation parameter, β/β0, were recorded and compared against a reference plot. It was observed that the rejuvenator had the effect of restoring the nonlinear properties to those corresponding to a virgin sample after a sufficient amount of dwell time. The ability of the rejuvenator to fully penetrate and act on the binder was observed to be dependent on the porosity and aggregate structure, and thus varied for each specimen. As a result, some portions of the binder were restored to a greater extent than others. This non-uniform nature was captured via the nonlinear ultrasonic technique.

  15. A study on engineering characteristics of asphalt concrete using filler with recycled waste lime.

    Science.gov (United States)

    Sung Do, Hwang; Hee Mun, Park; Suk keun, Rhee

    2008-01-01

    This study focuses on determining the engineering characteristics of asphalt concrete using mineral fillers with recycled waste lime, which is a by-product of the production of soda ash (Na(2)CO(3)). The materials tested in this study were made using a 25%, 50%, 75%, and 100% mixing ratio based on the conventional mineral filler ratio to analyze the possibility of using recycled waste lime. The asphalt concretes, made of recycled waste lime, hydrated lime, and conventional asphalt concrete, were evaluated through their fundamental engineering properties such as Marshall stability, indirect tensile strength, resilient modulus, permanent deformation characteristics, moisture susceptibility, and fatigue resistance. The results indicate that the application of recycled waste lime as mineral filler improves the permanent deformation characteristics, stiffness and fatigue endurance of asphalt concrete at the wide range of temperatures. It was also determined that the mixtures with recycled waste lime showed higher resistance against stripping than conventional asphalt concrete. It was concluded from various test results that a waste lime can be used as mineral filler and, especially, can greatly improve the resistance of asphalt concrete to permanent deformation at high temperatures.

  16. Calculation of the temperature of asphalt concrete at making the joints of multilane road pavement of non-rigid type

    OpenAIRE

    Giyasov Botir Iminzhonovich; Kupriyanov Roman Valer’evich; Andrianov Konstantin Anatol’evich; Zubkov Anatoliy Fedorovich

    2015-01-01

    The construction quality of road surface of non-rigid type essentially depend on providing the temperature regimes in the process of laying and packing of hot asphalt concrete mixtures. In order to provide the required characteristics of asphalt concrete due to the surface width it is necessary to provide the temperature regimes of hot asphalt concrete mixture in the zones of lane connection. The hot mixture is promptly cooling right after laying within several minutes, which results, accordi...

  17. Modified rubberized stone matrix asphalt for Nineveh roads

    Institute of Scientific and Technical Information of China (English)

    Al-Hadidy AI; TAN Yi-qiu

    2008-01-01

    To evaluate the effects of Crumb Rubber Modifiers (CRMS) on basic engineering properties (i. e.Marshall, tensile strength, and compressive strength) of stone matrix asphalt mixtures, the ASTM testing and procedures were employed. Results of the evaluation were used to quantify the effect of CRM source and CRM content on engineering properties at testing temperatures of 25℃and 60℃. Statistical models were developed, which represent the nature of effects on performance-related properties of stone matrix asphalt mixtures.

  18. Rendering the loss of strength in dry concretes with addition of milled asphalt through microscopic analysis

    Directory of Open Access Journals (Sweden)

    T. Sachet

    Full Text Available Milled asphalt removed from old pavement carpets requires tenable handling easily reachable through its incorporation within other paving materials. This work deals with the effects of such incorporation to dry compacted concretes. Fine, intermediate, coarse and whole portions of milled asphalts were blended to a reference concrete. Mechanical tests disclosed remarkable losses on its strengths and modulus of elasticity; for the stereoscope and scanning microscopy pointed out impaired transition zones between the cement paste and the milled aggregates involved by thin asphalt films. Nevertheless, the mechanical results shown that the concretes with incorporated milled asphalt aggregates are suitable for use in pavement layers as bases and sub-bases even with reduced mechanical parameters.

  19. Utilization of Recycled Asphalt Concrete with Warm Mix Asphalt and Cost-Benefit Analysis

    OpenAIRE

    Julide Oner; Burak Sengoz

    2015-01-01

    The asphalt paving industries are faced with two major problems. These two important challenges are generated with an increase in demand for environmentally friendly paving mixtures and the problem of rapidly rising raw materials. Recycling of reclaimed asphalt pavement (RAP) is a critical necessity to save precious aggregates and reduce the use of costly bitumen. Warm Mix Asphalt (WMA) technology provides not only the option of recycling asphalt pavement at a lower temperature than the tempe...

  20. The Development of Recycling Agent for Asphalt Pavement

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A type of recycling agent was developed and its use for modifying used asphalt is described.The results show that the viscosity and three main properties of the aged asphalt were remarkably improved.With 5%-7% content of recycling agent, the main properties of recycled asphalt comported with China GB asphalt standard AH-70 and the recycled asphalt concrete could be used as high-grade highway.Furthermore,the recycling mechanism of the aged asphalt is discussed.

  1. Characteristics and applications of high-performance fiber reinforced asphalt concrete

    Science.gov (United States)

    Park, Philip

    Steel fiber reinforced asphalt concrete (SFRAC) is suggested in this research as a multifunctional high performance material that can potentially lead to a breakthrough in developing a sustainable transportation system. The innovative use of steel fibers in asphalt concrete is expected to improve mechanical performance and electrical conductivity of asphalt concrete that is used for paving 94% of U. S. roadways. In an effort to understand the fiber reinforcing mechanisms in SFRAC, the interaction between a single straight steel fiber and the surrounding asphalt matrix is investigated through single fiber pull-out tests and detailed numerical simulations. It is shown that pull-out failure modes can be classified into three types: matrix, interface, and mixed failure modes and that there is a critical shear stress, independent of temperature and loading rate, beyond which interfacial debonding will occur. The reinforcing effects of SFRAC with various fiber sizes and shapes are investigated through indirect tension tests at low temperature. Compared to unreinforced specimens, fiber reinforced specimens exhibit up to 62.5% increase in indirect tensile strength and 895% improvements in toughness. The documented improvements are the highest attributed to fiber reinforcement in asphalt concrete to date. The use of steel fibers and other conductive additives provides an opportunity to make asphalt pavement electrically conductive, which opens up the possibility for multifunctional applications. Various asphalt mixtures and mastics are tested and the results indicate that the electrical resistivity of asphaltic materials can be manipulated over a wide range by replacing a part of traditional fillers with a specific type of graphite powder. Another important achievement of this study is development and validation of a three dimensional nonlinear viscoelastic constitutive model that is capable of simulating both linear and nonlinear viscoelasticity of asphaltic materials. The

  2. A study of sound absorption by street canyon boundaries and asphalt rubber concrete pavement

    Science.gov (United States)

    Drysdale, Graeme Robert

    A sound field model, based on a classical diffusion equation, is extended to account for sound absorption in a diffusion parameter used to model sound energy in a narrow street canyon. The model accounts for a single sound absorption coefficient, separate accommodation coefficients and a combination of separate absorption and accommodation coefficients from parallel canyon walls. The new expressions are compared to the original formula through numerical simulations to reveal the effect of absorption on sound diffusion. The newly established analytical formulae demonstrate satisfactory agreement with their predecessor under perfect reflection. As well, the influence of the extended diffusion parameter on normalized sound pressure levels in a narrow street canyon is in agreement with experimental data. The diffusion parameters are used to model sound energy density in a street canyon as a function of the sound absorption coefficient of the street canyon walls. The acoustic and material properties of conventional and asphalt rubber concrete (ARC) pavement are also studied to assess how the crumb rubber content influences sound absorption in street canyons. The porosity and absolute permeability of compacted specimens of asphalt rubber concrete are measured and compared to their normal and random incidence sound absorption coefficients as a function of crumb rubber content in the modified binder. Nonlinear trends are found between the sound absorption coefficients, porosity and absolute permeability of the compacted specimens and the percentage of crumb rubber in the modified binders. The cross-sectional areas of the air voids on the surfaces of the compacted specimens are measured using digital image processing techniques and a linear relationship is obtained between the average void area and crumb rubber content. The measured material properties are used to construct an empirical formula relating the average porosity, normal incidence noise reduction coefficients and

  3. The use of natural sand from lampusatu beach, kabupatenmerauke, papua for mixed asphalt concrete

    Science.gov (United States)

    Huwae, D. D. M.; Parera, L. R.; Alpius; Tanijaya, J.

    2017-05-01

    The natural sand from LampuSatu Beach, KabupatenMerauke, Papua, is often used as building material by local people. This research aims to test the use of this natural sand for mixed asphalt concrete. Asphalt Concrete Wearing Course (AC-WC) with bitumen penetration 60/70 and variations of asphalt content 5%, 6%, 7%, 8% and 9% are used in this research. Testing result shows the stability 1372.17 kg, VIM 3.95%, VMA 16.81%, Flow 4.14 mm, and MQ 332.89 kg/mm. It has fulfilled the standard requirements set by Indonesian Director General for Highways. The percentage of Optimum Asphalt Content (OAC) is 7% and the Index of Retained Strength (IRS) is 107.84% (≥ 75%). These indicate that the mixture can fulfill the Stability and Marshall Immersion Test.

  4. The Use of Waste Plastic as a Partial Substitution Aggregate in Asphalt Concrete Pavement

    Directory of Open Access Journals (Sweden)

    Imam Aschuri

    2016-04-01

    Full Text Available As a developing country, Indonesia faces serious problems managing solid waste such as plastic. Annually, Indonesia produces approximately 5.4 million tons of waste plastic, accounting for 14% of the country’s total solid waste production. Using waste plastic as a partial substitution aggregate in asphalt concrete pavement would be one of solutions for reducing environmental problems from the high volume of waste plastic. Previous studies show that it may be possible to use waste plastic in road pavement to improve the engineering performance of road pavement and increase its service life. This study investigates the performance of asphalt concrete mixtures containing varying amounts of waste plastic as a partial aggregate substitution as compared to that of conventional mixtures. The waste plastic used in this study was chopped into small pieces of approximately passing sieve number 30 and retained sieve number 40, which would replace (by weight a portion of the mineral aggregates. All mixtures were prepared using 5.82% optimum bitumen content. The performance of asphalt concrete characteristics was studied using the Marshall test, The Indirect Tensile Strength (ITS test, The Indirect Tensile Stiffness Modulus (ITSM test, and the Cantabro Loss (CL test in terms of strength, stiffness modulus, and durability characteristics. In general, laboratory results showed that asphalt concrete mixtures containing waste plastic have higher performance than conventional asphalt concrete mixtures.

  5. Characterization and thermal behavior of polymer-modified asphalt

    Directory of Open Access Journals (Sweden)

    Maria da Conceição Cavalcante Lucena

    2004-12-01

    Full Text Available A styrene-butadiene-styrene modified asphalt cement was characterized by infrared, differential scanning calorimetry, thermogravimetric analysis and empirical tests such as ring and ball softening point, penetration and elastic recovery. After aging in the rolling thin-film oven, the polymer-modified asphalt presented structural changes relating to oxidation of the material. The infrared spectra showed an increase in hydroxyl groups and the formation of carbonyl compounds and sulphoxides. The percentage of crystallized fraction calculated from differential scanning calorimetry was 0.41%. Thermogravimetric analyses in inert and oxidative atmospheres revealed distinct events during thermal decomposition; the initial activation energies were similar, but changed as the process evolved.

  6. HOW TO OBTAIN ECONOMICALLY EFFICIENT ASPHALT CONCRETE MIXTURES FOR CONSTRUCTIVE AUTOMOBILE ROAD AND STREET PAVEMENTS

    Directory of Open Access Journals (Sweden)

    V. A. Verenko

    2009-01-01

    Full Text Available The paper describes a methodology for evaluation of technical and economic efficiency of asphalt concrete mixture components. The method allows to perform a directed search for new materials which are used for mixture preparation and it also provides an efficient use of monetary funds. Firstly, it is possible to obtain this result due to optimum price-quality ratio of asphalt mixture which is determined by its service life in a pavement; secondly, it is possible to obtain this result due to  exclusion of errors while selecting components of the asphalt mixture out of the whole range applied presently in the world practice.

  7. Epoxy asphalt concrete is a perspective material for the construction of roads

    Science.gov (United States)

    Vyrozhemskyi, Valerii; Kopynets, Ivan; Kischynskyi, Sergii; Bidnenko, Nataliia

    2017-09-01

    An effective way to increase the durability of asphalt concrete pavements that are subject to high traffic loads and adverse weather and climatic factors is the use of polymer additives which drastically improve the rheological and physical-mechanical properties of bitumen. The use of thermosetting polymers including epoxy resins for asphalt and bitumen modification is seen as a perspective solution for this issue. Conducted at DerzhdorNDI SE studies have proved high riding qualities of asphalt pavements that contain epoxy resins. When replacing 20-35% of bitumen with epoxy component, a significant improvement in strength characteristics of asphalt pavement is noted, especially at elevated temperatures. Specific feature of epoxy asphalt concrete is its ability to gain strength over a long-term operation. Thus, despite the increased cost of epoxy asphalt concrete, long service life of pavements on its basis (up to 30 years as predicted) ensures a high profitability of using this material, especially on the roads with heavy traffic and severe traffic conditions.

  8. Preparation and Performance of Asphalt Compound Modified with Waste Crumb Rubber and Waste Polyethylene

    Directory of Open Access Journals (Sweden)

    Yuqiao Yang

    2016-01-01

    Full Text Available Three kinds of modified asphalt were prepared by adding waste crumb rubber (WCR, waste polyethylene (WPE, and WCR/WPE to base asphalt, respectively. The influence of different doses on the performance of modified asphalt, such as 25°C penetration, softening point, 5°C ductility, and 135°C, 165°C viscosity, was studied, and the modification mechanism of modified asphalt was discussed through the fluorescence microscope. As the waterproofing materials, the waterproofness of WCR/WPE compound modified asphalt was tested. The results show that the WPE modified asphalt has excellent resistance to high temperature and WCR modified asphalt has good low temperature resistance. The resistance to deformation ability of WPE modified asphalt is better than that of the WCR modified asphalt. The 135°C viscosity of compound modified asphalt is better than that of WPE and WCR modified asphalt. In addition, the waterproofness of compound modified asphalt using waterproofing materials is better than that of common waterproofing materials.

  9. The shakeout scenario: Meeting the needs for construction aggregates, asphalt, and concrete

    Science.gov (United States)

    Langer, W.H.

    2011-01-01

    An Mw 7.8 earthquake as described in the ShakeOut Scenario would cause significantdamage to buildings and infrastructure. Over 6 million tons of newly mined aggregate would be used for emergency repairs and for reconstruction in the five years following the event. This aggregate would be applied mostly in the form of concrete for buildings and bridges, asphalt or concrete for pavement, and unbound gravel for applications such as base course that goes under highway pavement and backfilling for foundations and pipelines. There are over 450 aggregate, concrete, and asphalt plants in the affected area, some of which would be heavily damaged. Meeting the increased demand for construction materials would require readily available permitted reserves, functioning production facilities, a supply of cement and asphalt, a source of water, gas, and electricity, and a trained workforce. Prudent advance preparations would facilitate a timely emergency response and reconstruction following such an earthquake. ?? 2011, Earthquake Engineering Research Institute.

  10. Bridge deck repair and protective systems: latex modified concrete topping. Interim report

    Energy Technology Data Exchange (ETDEWEB)

    Swanson, H.N.

    1984-07-01

    Measures to reduce or eliminate bridge deck deterioration by the use of various protective systems have been the subject of a series of reports begun in 1976. This report presents current observations of latex-modified deck-topping concrete protective systems. Latex-modified concrete topping has not provided long-term protection for the ten structures under evaluation in Colorado. Cost comparisons are made between repair with latex-modified concrete and deck replacement. Over a 40-year period, replacement costs are slightly less than rehabilitation costs. Greater control of the curing of deck-topping materials may reduce shrinkage cracking. Nightime paving, cooler calmer weather and higher humidity would increase the probability of success on latex-modified concrete to rehabilitation projects. Asphalt membrane and asphalt overlay are also suggested to increase the probability of success.

  11. Modification of asphaltic concrete with a mineral polymeric additive based on butadiene-styrene rubber and chemically precipitated calcium carbonate

    Directory of Open Access Journals (Sweden)

    S. I. Niftaliev

    2016-01-01

    Full Text Available Modification of asphaltic concrete with a mineral polymeric additive based on butadiene – styrene rubber and chemically precipitated calcium carbonate. This paper presents the results of the study of physical – mechanical and service properties of the asphaltic concrete modified with the mineral polymeric composition. Calcium carbonate is used both as a filler and a coagulant. The chalk was preliminarily ground and hydrophobizated by stearic acid. These operations contribute to even distribution of the filler and interfere with lump coagulation. As a result of the experiments, it was found that the best results were obtained by combining the operations of dispersion and hydrophobization. The optimal amount of stearic acid providing the finest grinding in a ball mill is a content from 3 to 5% by weight. The optimal grinding time of the filler was found (4–6 hours. With increasing dispersion time the particles form agglomerates. Filling the butadiene styrene latex with the hydrophobic fine-grained calcium carbonate was carried out in the laboratory mixer. As a result of the experimental works, it was found that the best distribution of the filler takes place with ratio of rubber: chalk – 100:400. The resulting modifier was subjected to the thermal analysis on the derivatograph to determine its application temperature interval. A marked reduction in weight of the mineral polymeric modifier begins at 350 °C. Thus, high temperature of the modifier destruction allows to use it at the temperature of the technological process of asphaltic concrete preparation (up to 170 °C. It was found that an increase in the amount of the carbonate filler in the rubber SKS 30АRК significantly increases its thermal resistance and connection of the polymer with the chalk in the composition.

  12. Effect of Carbon Nanofiber on Mechanical Behavior of Asphalt Concrete

    Directory of Open Access Journals (Sweden)

    Saeed Ghaffarpour Jahromi

    2015-09-01

    Full Text Available Uses of fibers to improve material properties have a scientific background in recent years in civil engineering. Use of Nanofiber reinforcement of materials refers to incorporating materials with desired properties within some other materials lacking those properties. Use of fibers for improvement is not a new phenomenon as the technique of fiber-reinforced bitumen began as early as 1950, but using nanofiber is a new idea. In this research the mechanical properties of asphalt mixture that have been modified with carbon nanofiber were investigated using mechanical tests, which can improve the performance of flexible pavements. To evaluate the effect of nanofiber contents on bituminous mixtures, laboratory investigations were carried out on the samples with and without nanofibers. During the course of this study, various tests were undertaken applying the Marshall test, indirect tensile test, resistance to fatigue cracking by using repeated load indirect tensile test and creep test. Carbon nanofiber exhibited consistency in results and it was observed that the addition of nanofiber can change the properties of bituminous mixtures, increase its stability and decrease the flow value. Results indicate that nanofiber have the potential to resist structural distress in the pavement and thus improve fatigue by increasing resistance to cracks or permanent deformation, when growing traffic loads. On the whole, the results show that the addition of carbon nanofiber will improve some of the mechanical properties such as fatigue and deformation in the flexible pavement.

  13. Attenuation of foot pressure during running on four different surfaces: asphalt, concrete, rubber, and natural grass.

    Science.gov (United States)

    Tessutti, Vitor; Ribeiro, Ana Paula; Trombini-Souza, Francis; Sacco, Isabel C N

    2012-01-01

    The practice of running has consistently increased worldwide, and with it, related lower limb injuries. The type of running surface has been associated with running injury etiology, in addition other factors, such as the relationship between the amount and intensity of training. There is still controversy in the literature regarding the biomechanical effects of different types of running surfaces on foot-floor interaction. The aim of this study was to investigate the influence of running on asphalt, concrete, natural grass, and rubber on in-shoe pressure patterns in adult recreational runners. Forty-seven adult recreational runners ran twice for 40 m on all four different surfaces at 12 ± 5% km · h(-1). Peak pressure, pressure-time integral, and contact time were recorded by Pedar X insoles. Asphalt and concrete were similar for all plantar variables and pressure zones. Running on grass produced peak pressures 9.3% to 16.6% lower (P rubber was greater than on concrete for the rearfoot and midfoot. The behaviour of rubber was similar to that obtained for the rigid surfaces - concrete and asphalt - possibly because of its time of usage (five years). Running on natural grass attenuates in-shoe plantar pressures in recreational runners. If a runner controls the amount and intensity of practice, running on grass may reduce the total stress on the musculoskeletal system compared with the total musculoskeletal stress when running on more rigid surfaces, such as asphalt and concrete.

  14. Investigating the Properties of Asphalt Concrete Containing Glass Fibers and Nanoclay

    Directory of Open Access Journals (Sweden)

    Hasan Taherkhani

    2016-06-01

    Full Text Available The performance of asphaltic pavements during their service life is highly dependent on the mechanical properties of the asphaltic layers. Therefore, in order to extend their service life, scientists and engineers are constantly trying to improve the mechanical properties of the asphaltic mixtures. One common method of improving the performance of asphaltic mixtures is using different types of additives. This research investigated the effects of reinforcement by randomly distributed glass fibers and the simultaneous addition of nanoclayon some engineering properties of asphalt concrete have been investigated. The properties of a typical asphalt concrete reinforced by different percentages of glass fibers were compared with those containing both the fibers and nanoclay. Engineering properties, including Marshall stability, flow, Marshall quotient, volumetric properties and indirect tensile strength were studied. Glass fibers were used in different percentages of 0.2, 0.4 and 0.6% (by weight of total mixture, and nanoclay was used in 2, 4 and 6% (by the weight of bitumen. It was found that the addition of fibers proved to be more effective than the nanoclay in increasing the indirect tensile strength. However, nanoclay improved the resistance of the mixture against permanent deformation better than the glass fibers. The results also showed that the mixture reinforced by 0.2% of glass fiber and containing 6% nanoclay possessed the highest Marshall quotient, and the mixture containing 0.6% glass fibers and 2% nanoclay possessedthe highest indirect tensile strength.

  15. Determining the healing potential of asphalt concrete mixtures--a pragmatic approach

    NARCIS (Netherlands)

    Erkens, S.; Vliet, D. van; Dommelen, A. van; Leegwater, G.A.

    2012-01-01

    Most design methods for pavements use a factor explaining the difference between pavement life predictions from design models and performance in the road [1]. Part of this correction factor is healing, the natural capacity of asphalt concrete to recover in rest periods, which generally are not prese

  16. Reducing the environmental impact of concrete and asphalt: a scenario approach

    NARCIS (Netherlands)

    Blankendaal, T.; Schuur, P.C.; Voordijk, J.T.

    2014-01-01

    In this paper, measures are evaluated to reduce the environmental impact of concrete and asphalt. Several composition scenarios are designed for these materials and are evaluated based on their environmental performance using life-cycle assessment (LCA). The effect of low-energy production technique

  17. Damage development in the adhesive zone and mortar of porous asphalt concrete

    NARCIS (Netherlands)

    Mo, L.T.

    2010-01-01

    This research is focused on damage development in the adhesive zone and the mortar of porous asphalt concrete. The motive of this research is the loss of stone from the pavement surface, the so-called ravelling of noise reducing surface wearing courses. Ravelling is the dominant defect of porous asp

  18. The Research on Improvement of Low Temperature Stability for Diatomite Modified Asphalt Mixture with PE Particles

    Directory of Open Access Journals (Sweden)

    HU Qiusheng

    2015-01-01

    Full Text Available In light of the lake of low temperature stability for diatomaceous which used as asphalt modifier.Stat the research with the diatomite produced at Jilin Changbai, using the way of low temperature bending test to evaluate the PE and diatomite composite modified asphalt mixture’s low temperature crack resistance performance. The results showed that after the diatomite and PE composite modified asphalt mixture has the best advantage of anti-cracking performance under low-temperature environment,which is better than PE modified asphalt mixture and the matrix asphalt mixture. As a result,asphalt mixture being composite modified by diatomite and PE could significantly improve asphalt mixture’s low temperature stable performance.

  19. Rheological Characterization of Warm-Modified Asphalt Mastics Containing Electric Arc Furnace Steel Slags

    Directory of Open Access Journals (Sweden)

    M. Pasetto

    2016-01-01

    Full Text Available The environmental sustainability of road materials and technologies plays a key role in pavement engineering. In this sense, the use of Warm Mix Asphalt (WMA, that is, a modified asphalt concrete that can be produced and applied at lower temperature, is considered an effective solution leading to environmental and operational benefits. The environmental sustainability of WMA can be further enhanced with the inclusion of steel slag in partial substitution of natural aggregates. Nevertheless, such innovative material applied at lower temperatures containing warm additives and steel slag should be able to guarantee at least the same performance of traditional hot mix asphalts, thus assuring acceptable mechanical properties and durability. Therefore, the purpose of this study is to investigate the rheological behaviour of bituminous mastics obtained combining a warm-modified binder and a filler (material passing to 0.063 mm coming from electric arc furnace steel slag. To evaluate the influence of both warm additive and steel slag, a plain binder and limestone filler were also used for comparison purposes. Complex modulus and permanent deformation resistance of bitumens and mastics were assessed using a dynamic shear rheometer. Experimental results showed that steel slag warm mastics assure enhanced performance demonstrating promising applicability.

  20. Performance evaluation of open-graded epoxy asphalt concrete with two nominal maximum aggregate sizes

    Institute of Scientific and Technical Information of China (English)

    罗桑; 钱振东; 薛永超

    2015-01-01

    Open-graded friction course (OGFC) is applied to pavement surfaces to increase driving safety under wet conditions, and recently, to reduce tire/pavement noise. The durability of OGFC, however, has been a concern since conventional OGFC mixes last typically less than ten years before major maintenance or rehabilitation is needed. This work investigates a new open-graded asphalt mixture that uses epoxy asphalt as binder to improve mix durability. One type of epoxy asphalt that has been successfully applied to dense-graded asphalt concrete for bridge deck paving was selected. A procedure of compacting the mix into slab specimens was developed and a series of laboratory tests were conducted to evaluate the performance of the new mix, including Cantabro loss, permeability, friction, shear strength, and wheel rutting tests. Results show superior overall performance of the open-graded epoxy asphalt mix compared to conventional open-graded asphalt mix. There are also preliminary indications that the OGFC mix with 4.75-mm NMAS gradation can improve the resistance performance to raveling, while the OGFC mix with 9.5-mm NMAS gradation can improve the performance of surface friction at a high slip speed.

  1. Performance evaluation of open-graded epoxy asphalt concrete with two nominal maximum aggregate sizes

    Institute of Scientific and Technical Information of China (English)

    罗桑; 钱振东; 薛永超

    2015-01-01

    Open-graded friction course(OGFC) is applied to pavement surfaces to increase driving safety under wet conditions, and recently, to reduce tire/pavement noise. The durability of OGFC, however, has been a concern since conventional OGFC mixes last typically less than ten years before major maintenance or rehabilitation is needed. This work investigates a new open-graded asphalt mixture that uses epoxy asphalt as binder to improve mix durability. One type of epoxy asphalt that has been successfully applied to dense-graded asphalt concrete for bridge deck paving was selected. A procedure of compacting the mix into slab specimens was developed and a series of laboratory tests were conducted to evaluate the performance of the new mix, including Cantabro loss, permeability, friction, shear strength, and wheel rutting tests. Results show superior overall performance of the open-graded epoxy asphalt mix compared to conventional open-graded asphalt mix. There are also preliminary indications that the OGFC mix with 4.75-mm NMAS gradation can improve the resistance performance to raveling, while the OGFC mix with 9.5-mm NMAS gradation can improve the performance of surface friction at a high slip speed.

  2. Influence of Polyethylene Glycol on Asphaltic Concrete for Cubical and Rod shaped Aggregates

    Directory of Open Access Journals (Sweden)

    U. Arun Kumar

    2014-02-01

    Full Text Available Aggregates are the principle material in pavement construction. Conventional road aggregates in India are natural aggregates obtained by crushing rocks. Aggregate characteristics such as particle size, shape, and texture etc.., influence the performance and serviceability of pavement. Pavements laid with polymer modified asphalt exhibits greater resistance to rutting, thermal cracking and fatigue damages and hence these were used at locations of higher stress. The present work concentrates on aggregate characteristics which include the shape indices. The particle shapes namely Cubical and Rod are being used in the study. The study shows the behavior of the two shapes of aggregate in terms of Penetration, Ductility, Softening Point and Marshall Stability tests with varying percentages of asphalt and also with varying the percentages of PEG. The results of unmodified asphalt mix are compared with the modified asphalt mix against some critical Marshall Mix parameters.

  3. Utilization of recycled asphalt concrete with warm mix asphalt and cost-benefit analysis.

    Science.gov (United States)

    Oner, Julide; Sengoz, Burak

    2015-01-01

    The asphalt paving industries are faced with two major problems. These two important challenges are generated with an increase in demand for environmentally friendly paving mixtures and the problem of rapidly rising raw materials. Recycling of reclaimed asphalt pavement (RAP) is a critical necessity to save precious aggregates and reduce the use of costly bitumen. Warm Mix Asphalt (WMA) technology provides not only the option of recycling asphalt pavement at a lower temperature than the temperature maintained in hot mixtures but also encourages the utilization of RAP and therefore saves energy and money. This paper describes the feasibility of utilizing three different WMA additives (organic, chemical and water containing) at recommended contents with different percentages of RAP. The mechanical properties and cost-benefit analysis of WMA containing RAP have been performed and compared with WMA without RAP. The results indicated that, 30%, 10% and 20% can be accepted as an optimum RAP addition related to organic, chemical and water containing additives respectively and organic additive with 30% RAP content has an appreciable increase in tensile strength over the control mix. It was also concluded that the RAP with WMA technology is the ability to reduce final cost compared to HMA and WMA mixtures.

  4. Utilization of recycled asphalt concrete with warm mix asphalt and cost-benefit analysis.

    Directory of Open Access Journals (Sweden)

    Julide Oner

    Full Text Available The asphalt paving industries are faced with two major problems. These two important challenges are generated with an increase in demand for environmentally friendly paving mixtures and the problem of rapidly rising raw materials. Recycling of reclaimed asphalt pavement (RAP is a critical necessity to save precious aggregates and reduce the use of costly bitumen. Warm Mix Asphalt (WMA technology provides not only the option of recycling asphalt pavement at a lower temperature than the temperature maintained in hot mixtures but also encourages the utilization of RAP and therefore saves energy and money. This paper describes the feasibility of utilizing three different WMA additives (organic, chemical and water containing at recommended contents with different percentages of RAP. The mechanical properties and cost-benefit analysis of WMA containing RAP have been performed and compared with WMA without RAP. The results indicated that, 30%, 10% and 20% can be accepted as an optimum RAP addition related to organic, chemical and water containing additives respectively and organic additive with 30% RAP content has an appreciable increase in tensile strength over the control mix. It was also concluded that the RAP with WMA technology is the ability to reduce final cost compared to HMA and WMA mixtures.

  5. Genotoxic effects of fumes from asphalt modified with waste plastic and tall oil pitch.

    Science.gov (United States)

    Lindberg, Hanna K; Väänänen, Virpi; Järventaus, Hilkka; Suhonen, Satu; Nygren, Jonas; Hämeilä, Mervi; Valtonen, Jarkko; Heikkilä, Pirjo; Norppa, Hannu

    2008-05-31

    As the use of recycled materials and industrial by-products in asphalt mixtures is increasing, we investigated if recycled additives modify the genotoxicity of fumes emitted from asphalt. Fumes were generated in the laboratory at paving temperature from stone-mastic asphalt (SMA) and from SMA modified with waste plastic (90% polyethylene, 10% polypropylene) and tall oil pitch (SMA-WPT). In addition, fumes from SMA, SMA-WPT, asphalt concrete (AC), and AC modified with waste plastic and tall oil pitch (AC-WPT) were collected at paving sites. The genotoxicity of the fumes was studied by analysis of DNA damage (measured in the comet assay) and micronucleus formation in human bronchial epithelial BEAS 2B cells in vitro and by counting mutations in Salmonella typhimurium strains TA98 and YG1024. DNA damage was also assessed in buccal leukocytes from road pavers before and after working with SMA, SMA-WPT, AC, and AC-WPT. The chemical composition of the emissions was analysed by gas chromatography/mass spectrometry. The SMA-WPT fume generated in the laboratory induced a clear increase in DNA damage in BEAS 2B cells without metabolic activation. The laboratory-generated SMA fume increased the frequency of micronucleated BEAS 2B cells without metabolic activation. None of the asphalt fumes collected at the paving sites produced DNA damage with or without metabolic activation. Fumes from SMA and SMA-WPT from the paving sites increased micronucleus frequency without metabolic activation. None of the asphalt fumes studied showed mutagenic activity in Salmonella. No statistically significant differences in DNA damage in buccal leukocytes were detected between the pre- and post-shift samples collected from the road pavers. However, a positive correlation was found between DNA damage and the urinary metabolites of polycyclic aromatic hydrocarbons (PAHs) after work shift, which suggested an association between occupational exposures during road paving and genotoxic effects. Our

  6. Effect of ageing on rheological properties of storage-stable SBS/sulfur-modified asphalts.

    Science.gov (United States)

    Zhang, Feng; Yu, Jianying; Wu, Shaopeng

    2010-10-15

    Oxidative ageing as an inevitable process in practical road paving has a great effect on the properties of polymer-modified asphalts (PMAs). In this article, the effect of short-term and long-term oxidative ageing on the rheological, physical properties and the morphology of the styrene-butadiene-styrene (SBS)- and storage-stable SBS/sulfur-modified asphalts was studied, respectively. The analysis on the rheological and physical properties of the PMAs before and after ageing showed the two major effects of ageing. On one hand, ageing prompted the degradation of polymer and increased the viscous behaviour of the modified binders, on the other, ageing changed the asphalt compositions and improved the elastic behaviour of the modified binders. The final performance of the aged binders depended on the combined effect. After ageing, the storage-stable SBS/sulfur-modified asphalts showed an obvious viscous behaviour compare with the SBS-modified asphalts and this led to an improved low-temperature creep property. The rutting resistance of the SBS-modified asphalts declined by the addition of sulfur due to the structural instability of the SBS/sulfur-modified asphalts. The rheological properties of the modified binders before and after ageing also depended strongly on the structural characteristics of SBS. The observation by using optical microscopy showed the compatibility between asphalt and SBS was improved with further ageing, especially for the storage-stable SBS/sulfur-modified asphalts.

  7. A study on the rheological properties of recycled rubber-modified asphalt mixtures.

    Science.gov (United States)

    Karacasu, Murat; Okur, Volkan; Er, Arzu

    2015-01-01

    Using waste rubber in asphalt mixes has become a common practice in road construction. This paper presents the results of a study on the rheological characteristics of rubber-modified asphalt (RMA) concrete under static and dynamic loading conditions. A number of static and dynamic creep tests were conducted on RMA mix specimens with different rubber sizes and contents, and a series of resonant column tests were conducted to evaluate the shear modulus and damping values. To simulate the stress-strain response of traffic-induced loading, the measurements were taken for different confining pressures and strain levels. The results of the study indicated that rubber modification increases stiffness and damping ratio, making it a very attractive material for use in road construction. However the grain size of the rubber is very important. Although RMA may cost up to 100% more than regular asphalt, the advantages it brings, such as an increased service life of the road and proper waste utilization contributing to a more sustainable infrastructure, may justify the added cost.

  8. A Study on the Rheological Properties of Recycled Rubber-Modified Asphalt Mixtures

    Directory of Open Access Journals (Sweden)

    Murat Karacasu

    2015-01-01

    Full Text Available Using waste rubber in asphalt mixes has become a common practice in road construction. This paper presents the results of a study on the rheological characteristics of rubber-modified asphalt (RMA concrete under static and dynamic loading conditions. A number of static and dynamic creep tests were conducted on RMA mix specimens with different rubber sizes and contents, and a series of resonant column tests were conducted to evaluate the shear modulus and damping values. To simulate the stress-strain response of traffic-induced loading, the measurements were taken for different confining pressures and strain levels. The results of the study indicated that rubber modification increases stiffness and damping ratio, making it a very attractive material for use in road construction. However the grain size of the rubber is very important. Although RMA may cost up to 100% more than regular asphalt, the advantages it brings, such as an increased service life of the road and proper waste utilization contributing to a more sustainable infrastructure, may justify the added cost.

  9. Environmental performance and mechanical analysis of concrete containing recycled asphalt pavement (RAP) and waste precast concrete as aggregate.

    Science.gov (United States)

    Erdem, Savaş; Blankson, Marva Angela

    2014-01-15

    The overall objective of this research project was to investigate the feasibility of incorporating 100% recycled aggregates, either waste precast concrete or waste asphalt planning, as replacements for virgin aggregates in structural concrete and to determine the mechanical and environmental performance of concrete containing these aggregates. Four different types of concrete mixtures were designed with the same total water cement ratio (w/c=0.74) either by using natural aggregate as reference or by totally replacing the natural aggregate with recycled material. Ground granulated blast furnace slag (GGBS) was used as a mineral addition (35%) in all mixtures. The test results showed that it is possible to obtain satisfactory performance for strength characteristics of concrete containing recycled aggregates, if these aggregates are sourced from old precast concrete. However, from the perspective of the mechanical properties, the test results indicated that concrete with RAP aggregate cannot be used for structural applications. In terms of leaching, the results also showed that the environmental behaviour of the recycled aggregate concrete is similar to that of the natural aggregate concrete. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. DEVELOPMENT OF METHODS IMPROVING INDUSTRIAL SAFETY OF TECHNOLOGICAL PROCESSES IN ASPHALT-CONCRETE PLANT MIXERS

    Directory of Open Access Journals (Sweden)

    I. A. Ivanova

    2010-05-01

    Full Text Available Problem statement. The problem of improvement of industrial safety of technol-ogical processes in mixers of asphalt-concrete plants is considered on the basis of analysis of organic impurities content in incomplete combustion products, and es-timation of efficiency of purification of asphalt-concrete plant emissions in the presence of “wet” flue gas purification system is given.Results and conclusions. It has been found that the efficiency of hydrocarbon fuel burning affects the amount of hydrophobic dust thrown into the atmosphere, and burning of heavy fuel oil is attended by significant incompleteness of fuel combustion, and this is connected with the processes of fuel dispersion and evapo-ration. The optimal measures for efficient combustion and cleaning of hydrophob-ic dust are described.

  11. 添加磷酸对沥青混凝土性能影响%Effect of Phosphoric Acid on Performance of Asphalt Concrete

    Institute of Scientific and Technical Information of China (English)

    董苋伯; 吴进良

    2012-01-01

    以AC-20为基底沥青,磷酸作为改质剂,研究添加磷酸对沥青胶浆性质的影响,并以磷酸改质沥青作为马歇尔试体,研究添加磷酸对沥青混凝土性能的影响。经过试验,添加磷酸确实有效增加沥青胶浆的劲度,也会加速沥青胶浆的老化;增加混凝土承载力、抵抗车辙变形能力、抗张强度和耐磨损能力。添加磷酸也会降低沥青混凝土抗水侵害能力,磷酸的添加量越多,沥青混凝土水害的情形越严重,根据试验结果,建议磷酸可以添加到2%。%This study used AC-20 as the basis asphalt and phosphoric acid was used as a modifier to evaluate effect of phosphoric acid on the properties of asphalt, marshall samples were fabricated with phosphoric acid modified asphalt to study effect of phosphoric acid on the performance of asphalt concerte. According to result of tests, adding the phosphoric acid would increase asphalt stiffness, but would accelerate the as- phalt aging. Because adding the phosphoric acid would increase asphalt stiffness, the resistance of rutting, tensile strength and the resistance of wearing of asphalt concrete were all improve. But the resistance to moisture damage was reduced. Results of the tests, showed that phosphoric acid could be added about 2%.

  12. INVESTIGATING EFFECTS OF AMINE BASED MODIFIER ON RECYCLED ASPHALT SHINGLES BLENDING

    OpenAIRE

    2014-01-01

    A laboratory study was conducted to investigate the effects of Amine based modifier on rheological characteristics of particle filled viscous medium such as asphalt binder in presence of Recycled Asphalt Shingles (RAS). In this study, virgin asphalt binder (PG 64-22), three different percentages (20, 30 and 40%) of tear-off shingles and modifiers; Rediset, Evotherm and Bio-binder were used. The tear-off shingles acquired from local reroofing company in Greensboro, North Carolina; were finely ...

  13. Evaluation of permanent deformation and durability of epoxidized natural rubber modified asphalt mix

    Science.gov (United States)

    Al-Mansob, Ramez A.; Ismail, Amiruddin; Rahmat, Riza Atiq O. K.; Nazri Borhan, Muhamad; Alsharef, Jamal M. A.; Albrka, Shaban Ismael; Rehan Karim, Mohamed

    2017-09-01

    The road distresses have caused too much in maintenance cost. However, better understandings of the behaviours and properties of asphalt, couples with greater development in technology, have allowed paving technologists to examine the benefits of introducing additives and modifiers. As a result, modifiers such as polymers are the most popular modifiers used to improve the performance of asphalt mix. This study was conducted to investigate the use of epoxidized natural rubber (ENR) to be mixed with asphalt mix. Tests were conducted to investigate the performance characteristics of ENR-asphalt mixes, where the mixes were prepared according to the wet process. Mechanical testing on the ENR-asphalt mixes have demonstrated that the asphalt mix permanent deformation performance at high temperature was found to be improved compared to the base mixes. However, the durability studies have indicated that ENR-asphalt mixes are slightly susceptible with the presence of moisture. The durability of the ENR-asphalt mixes were found to be enhanced in term of permanent deformation at high and intermediate temperatures compared to the base asphalt mixes. As conclusion, asphalt pavement performance can be enhanced by using ENR as modifier to face the major road distresses.

  14. Investigation of Properties of Asphalt Concrete Containing Boron Waste as Mineral Filler

    Directory of Open Access Journals (Sweden)

    Cahit GÜRER

    2016-05-01

    Full Text Available During the manufacture of compounds in the boron mining industry a large quantity of waste boron is produced which has detrimental effects on the environment. Large areas have to be allocated for the disposal of this waste. Today with an increase in infrastructure construction, more efficient use of the existing sources of raw materials has become an obligation and this involves the recycling of various waste materials. Road construction requires a significant amount of raw materials and it is possible that substantial amounts of boron-containing waste materials can be recycled in these applications. This study investigates the usability of boron wastes as filler in asphalt concrete. For this purpose, asphalt concrete samples were produced using mineral fillers containing 4%, 5%, 6%, 7% and 8% boron waste as well as a 6% limestone filler (6%L as the control sample. The Marshall Design, mechanical immersion and Marshall Stability test after a freeze-thaw cycle and indirect tensile stiffness modulus (ITSM test were performed for each of the series. The results of this experimental study showed that boron waste can be used in medium and low trafficked asphalt concrete pavements wearing courses as filler.

  15. Choosing mineral carrier of nanoscale additives for asphalt concrete

    Directory of Open Access Journals (Sweden)

    Inozemtsev Sergey Sergeevich

    2014-03-01

    Full Text Available At present time the operation life of the majority of roads is essentially shorter than required. The reason for it is the increase in traffic intensity and axle loads of automobile transport. The obvious reasons for early wear of roads are the low quality of the components used and low industrial standards while producing asphalt pavement. In this paper the mineral material was selected as a carrier of nanoscale additives for asphalt. The optimal modes for grinding mineral materials were identified, which provide correspondence of their structure parameters with the developed model. The influence of different mineral nanomodifier carriers on the structure formation processes was estimated. It is shown that among a number of mineral materials diatomite has high activity in relation to the bitumen, because it has a highly porous structure. It is also shown that as a result of lighter fractions of bitumen adsorption on the border of phase interface, diatomite and bitumen changes from the free state to the film, and solvate shell of bitumen is saturated with asphaltenes. With the help of IR spectroscopy the authors defined the nature of the diatomite and bitumen interaction and proved that in the process of their interaction there occurs physical adsorption with additional absorption of bitumen components into the pore space of diatomite grains.

  16. Preparation, Characterization and Hot Storage Stability of Asphalt Modified by Waste Polyethylene Packaging

    Institute of Scientific and Technical Information of China (English)

    Changqing Fang; Ying Zhang; Qian yu; Xing Zhou; Dagang Guo; Ruien Yu; Min Zhang

    2013-01-01

    Waste polyethylene packaging (WPE) was used to modify asphalt,and hot storage stability of the modified asphalt was studied in this paper.The morphological change and component loss of WPE modified asphalt were characterized by fluorescence microscopy,Fourier transform infrared spectroscopy (FT-IR),differential scanning calorimetry (DSC),thermogravimetry (TG) and isolation testing.In addition,the mechanism of the hot storage stability of WPE modified asphalt was discussed.The results showed that the modification of asphalt with WPE was a physical process.It was found that the filament or partly network-like structure formed in the modified asphalt system was beneficial to improving the hot storage stability.Moreover,the addition of WPE resulted in a decrease in both the light components volatilization and the macromolecules decomposition of asphalt.It was demonstrated that when the content of WPE in matrix asphalt was less than 10 wt%,the service performances of modified asphalt could be better.

  17. Evaluation of rheological and thermic properties of neat and modified asphalt with a waste of LDPE

    Directory of Open Access Journals (Sweden)

    William Andrés Castro López

    2016-01-01

    Full Text Available Context: The asphalt technology and modified asphalt mixtures has been widely used and studied, worldwide. Adding polymers to asphalt modifies mechanical, chemical and rheological properties, trying to improve behavior of the mixtures subjected to different environmental and load conditions. The paper report results from rheological and thermal characterization on conventional 60-70 asphalt cement and 60-70 asphalt cement modified by introducing a waste of low density polyethylene (LDPE. Method: Modification of the asphalt was performed by wet way in a proportion of LDPE/CA=5% with respect to the mass. Rheological (using DSR, Thermogravimetry (TGA and Differential Scanning Calorimetry (DSC techniques were performed. Results and Conclusions: The modified asphalt develops a remarkable increase in stiffness and improvement of the performance grade at high temperatures of service. Additionally, the modified asphalt is more resistant to oxidation and aging processes due to heat. However, the asphalt modified showed a decrease in crack resistance at low and intermediate temperatures of service.

  18. Short-Term Aging Effect on Properties of Sustainable Pavement Asphalts Modified by Waste Rubber and Diatomite

    National Research Council Canada - National Science Library

    Hanbing Liu; Liuxu Fu; Yubo Jiao; Jinglin Tao; Xianqiang Wang

    2017-01-01

    Waste utilization has gained more and more interest. In this study, crumb rubber and diatomite were used to modify asphalt binder and the short-term aging effects on the properties of modified asphalts were evaluated...

  19. The effect of long-term oxidation on the rheological properties of polymer modified asphalts

    Energy Technology Data Exchange (ETDEWEB)

    Yonghong Ruan; Richard R. Davison; Charles J. Glover [Texas A & M University, College Station, TX (United States). Department of Chemical Engineering

    2003-10-01

    The effect of long-term aging on rheological properties of polymer modified asphalt binders was studied. Modifiers included diblock poly(styrene-b-butadiene) rubber, triblock poly(styrene-b-butadiene-b-styrene), and tire rubber. Asphalt aging was carried out either at 60{sup o}C in a controlled environmental room or at 100{sup o}C in a pressure aging vessel (AASHTO Provisional Standards, 1993). Both dynamic shear properties and extensional properties were investigated. Polymer modification resulted in increased asphalt complex modulus at high temperatures, decreased asphalt complex modulus at low temperatures, broadened relaxation spectra, and improved ductility. Oxidative aging decreased asphalt temperature susceptibility, damaged the polymer network in binders, further broadened the relaxation spectrum, and diminished polymer effectiveness in improving asphalt ductility. 27 refs., 8 figs., 3 tabs.

  20. Self-healing of polymer modified concrete

    Directory of Open Access Journals (Sweden)

    Abd_Elmoaty M. Abd_Elmoaty

    2011-06-01

    Full Text Available Self healing phenomenon of concrete has been observed in traditional, fibrous, self compacting concrete. This phenomenon occurred mainly due to the presence of unhydrated cement particles in the presence of water. Mechanism of polymer in concrete depends on creating a layer and net of polymer around cement particles which enhances the properties of polymer modified concrete. This mechanism may affect the self healing of this type of concrete. This work aims to study the presence of the self healing phenomenon in polymer modified concrete and the related parameters. An experimental investigation on self healing of polymer modified concrete was undertaken. In this research work, effect of polymer type, polymer dose, cement content, cement type, w/cm ratio and age of damage were studied. The healing process extended up to 60 days. Ultrasonic pulse velocity measurements were used to evaluate the healing process. Results indicated that, the self healing phenomenon existed in polymer modified concrete as in traditional concrete. The increase of polymer dose increases the healing degree at the same healing time. This increase depends on polymer type. Also, the decrease of w/cm ratio reduces the self healing degree while the use of Type V Portland cement improves the self healing process compared with Type I Portland cement. Cement content has an insignificant effect on healing process for both concrete with and without polymer. In addition, the increase of damage age decreases the efficiency of self healing process.

  1. The design and analysis on asphalt concrete pavement%沥青混凝土路面设计分析

    Institute of Scientific and Technical Information of China (English)

    王星茹

    2016-01-01

    This paper introduced the design process of urban road asphalt pavement,discussed the material and type of asphalt concrete pave-ment,from the pavement structure combination design,pavement design index,pavement structure layer calculation and other aspects,elabora-ted the design method of asphalt concrete pavement,made the asphalt pavement meet the structure strength and stability requirements.%介绍了城市道路沥青路面设计的流程,论述了沥青混凝土面层的材料与类型,从路面结构组合设计、路面设计指标、路面结构层计算等方面,阐述了沥青混凝土路面的设计方法,使沥青路面满足结构强度和稳定性的要求.

  2. Using Pyrolized Carbon Black (PCB) from Waste Tires in Asphalt Pavement (Part 1, Limestone Aggregate)

    OpenAIRE

    Park, Taesoon; Lovell, C. W.

    1996-01-01

    This study presents the viability of using PCB as an additive in hot mix asphalt concrete. Different ratios of PCB (5%, 10%, 15%, and 20% by weight of asphalt) were blended with two grades of asphalt (AC-10 and AC-20). The complete behaviors of the PCB modified asphalt concrete were investigated by comprehensive laboratory testing and evaluation. The Marshall method was used to determine the optimum binder content and the mechanical properties and void relationships were investigated by th...

  3. Asphaltic Concrete Performance Under Heavy Fighter Aircraft Loading

    Science.gov (United States)

    1993-02-01

    compacted to determine the effects of overfilling and underfilling the voids in the aggregate. Density and voids filled with binder are two of the...concrete were also taken at different pass levels to determine the change in air voids with traffic. Damage parameters were defined to provide a...149 I 89 Voids Total Mix Data and Interpolated Values Versus Station .............................................. 150 90 Voids Filled

  4. Rheological evaluation of polymer-modified asphalt binders

    Directory of Open Access Journals (Sweden)

    Mônica Romero Santos Fernandes

    2008-09-01

    Full Text Available Currently, the most used polymer for asphalt binder modification is the thermoplastic elastomer styrene butadiene styrene (SBS and aromatic oil is commonly added to the mixtures to improve their compatibly. This paper proposes the use of oil shale from sedimentary rock as a compatibilizer agent for polymer-modified asphalt binder (PMB. PMBs were produced by mixing a bitumen with a linear SBS copolymer (3.5% (w.w-1 using two oil shale contents (2 and 4% and petroleum aromatic oil to evaluate comparatively the effect of the compatibilizer agent on the SBS PMB properties. The rheological characteristics of the SBS PMBs were analyzed in a dynamic shear rheometer (DSR and the morphology accessed by fluorescence optical microscopy. The viscoelastic behavior of the samples corroborated the results for the classical properties and varied according to the sample morphology and composition. The results indicate that the aromatic and shale oils have similar effects on the microstructure, storage stability and viscoelastic behavior of the PMBs. Thus, shale oil could be successfully used as a compatibilizer agent without loss of properties or could even replace the aromatic oil. Following the Superpave methodology it was observed that the linear- and radial-SBS PMBs and linear-SBS PMB with 2% of shale oil can be used up to 70 °C, and the linear-SBS PMBs with 4% of shale oil or 2% of aromatic oil can be used only up to 64 °C.

  5. Latex improvement of recycled asphalt pavement

    Science.gov (United States)

    Drennon, C.

    1982-08-01

    The performance of a single unmodified milled recycled asphalt concrete was compared to milled asphalt concrete modified by addition of three types of rubber latex. Latex was added at 2, 3, 5, and 8 percent latex by weight of asphalt in the asphalt concrete. Lattices used were a styrene butadiene (SBR), a natural rubber (NR), an acrylonitrile butadiene (NBR), and four varieties of out of specification SBR lattices. Marshall tests, while indecisive, showed a modest improvement in properties of SBR and NR added material at 3 and 5 percent latex. Addition of NBR latex caused deterioration in Marshall stability and flow over that of control. Repeated load tests were run using the indirect tensile test, analyzed by the VESYS program, which computes life of pavements. Repeated load tests showed improvement in asphalt concrete life when 3 and 5 percent SBR was added. Improvement was also shown by the out of specification SBR.

  6. Engineering characterisation of epoxidized natural rubber-modified hot-mix asphalt.

    Science.gov (United States)

    Al-Mansob, Ramez A; Ismail, Amiruddin; Yusoff, Nur Izzi Md; Rahmat, Riza Atiq O K; Borhan, Muhamad Nazri; Albrka, Shaban Ismael; Azhari, Che Husna; Karim, Mohamed Rehan

    2017-01-01

    Road distress results in high maintenance costs. However, increased understandings of asphalt behaviour and properties coupled with technological developments have allowed paving technologists to examine the benefits of introducing additives and modifiers. As a result, polymers have become extremely popular as modifiers to improve the performance of the asphalt mix. This study investigates the performance characteristics of epoxidized natural rubber (ENR)-modified hot-mix asphalt. Tests were conducted using ENR-asphalt mixes prepared using the wet process. Mechanical testing on the ENR-asphalt mixes showed that the resilient modulus of the mixes was greatly affected by testing temperature and frequency. On the other hand, although rutting performance decreased at high temperatures because of the increased elasticity of the ENR-asphalt mixes, fatigue performance improved at intermediate temperatures as compared to the base mix. However, durability tests indicated that the ENR-asphalt mixes were slightly susceptible to the presence of moisture. In conclusion, the performance of asphalt pavement can be enhanced by incorporating ENR as a modifier to counter major road distress.

  7. Engineering characterisation of epoxidized natural rubber-modified hot-mix asphalt

    Science.gov (United States)

    Al-Mansob, Ramez A.; Ismail, Amiruddin; Yusoff, Nur Izzi Md.; Rahmat, Riza Atiq O. K.; Borhan, Muhamad Nazri; Albrka, Shaban Ismael; Azhari, Che Husna; Karim, Mohamed Rehan

    2017-01-01

    Road distress results in high maintenance costs. However, increased understandings of asphalt behaviour and properties coupled with technological developments have allowed paving technologists to examine the benefits of introducing additives and modifiers. As a result, polymers have become extremely popular as modifiers to improve the performance of the asphalt mix. This study investigates the performance characteristics of epoxidized natural rubber (ENR)-modified hot-mix asphalt. Tests were conducted using ENR–asphalt mixes prepared using the wet process. Mechanical testing on the ENR–asphalt mixes showed that the resilient modulus of the mixes was greatly affected by testing temperature and frequency. On the other hand, although rutting performance decreased at high temperatures because of the increased elasticity of the ENR–asphalt mixes, fatigue performance improved at intermediate temperatures as compared to the base mix. However, durability tests indicated that the ENR–asphalt mixes were slightly susceptible to the presence of moisture. In conclusion, the performance of asphalt pavement can be enhanced by incorporating ENR as a modifier to counter major road distress. PMID:28182724

  8. A Study of Moisture Damage in Plastomeric Polymer Modified Asphalt Binder Using Functionalized AFM Tips

    Directory of Open Access Journals (Sweden)

    Rafiqul Tarefder

    2011-12-01

    Full Text Available In this study, moisture damage in plastomeric polymer modified asphalt binder is investigated using Atomic Force Microscopy (AFM with chemically functionalized AFM tips. Four different percentages of plastomeric polymers and two antistripping agents such as Kling Beta and Lime are used to modify a base asphalt binder. Chemical functional groups such as -COOH, -CH3, -NH3, and –OH, that are commonly present in plastomeric polymer modified asphalt system, are used to functionalize the AFM tips. The force distance mode of AFM is used to measure the adhesion forces between a modified asphalt sample surface and the functionalized AFM tips. This enables the measurement of adhesion within an asphalt binder system. It is shown that the adhesion force values in dry sample changed substantially from that in wet conditioned samples. It is evident from this study that plastomeric modification does not help reduce moisture damage in asphalt. The percentage change in adhesion forces due to moisture is about 20 nN for the lime modified samples, and about 50 nN for the Kling Beta modified samples. This indicates that lime is more effective than Kling Beta for reducing moisture damage in plastomeric polymer modified asphalt.

  9. CONCRETE BASED ON MODIFIED DISPERSE CEMENT SYSTEM

    Directory of Open Access Journals (Sweden)

    D. V. Rudenko

    2016-08-01

    Full Text Available Purpose. The article considers definition of the bond types occurring in a modified cement concrete matrix, and the evaluation of the quality of these links in a non-uniform material to determine the geometrical and physical relationships between the structure and the cement matrix modifiers. Methodology. To achieve this purpose the studies covered the microstructure of dispersed modified concrete cement matrix, the structure formation mechanism of the modified cement concrete system of natural hardening; as well as identification of the methods of sound concrete strength assessment. Findings. The author proposed a model of the spatial structure of the concrete cement matrix, modified by particulate reinforcement crystal hydrates. The initial object of study is a set of volume elements (cells of the cement matrix and the system of the spatial distribution of reinforcing crystallohydrates in these volume elements. It is found that the most dangerous defects such as cracks in the concrete volume during hardening are formed as a result of internal stresses, mainly in the zone of cement matrix-filler contact or in the area bordering with the largest pores of the concrete. Originality. The result of the study is the defined mechanism of the process of formation of the initial strength and stiffness of the modified cement matrix due to the rapid growth of crystallohydrates in the space among the dispersed reinforcing modifier particles. Since the lack of space prevents from the free growth of crystals, the latter cross-penetrate, forming a dense structure, which contributes to the growth of strength. Practical value. Dispersed modifying cement matrix provides a durable concrete for special purposes with the design performance characteristics. The developed technology of dispersed cement system modification, the defined features of its structure formation mechanism and the use of congruence principle for the complex of technological impacts of physical

  10. Generation of urban road dust from anti-skid and asphalt concrete aggregates.

    Science.gov (United States)

    Tervahattu, Heikki; Kupiainen, Kaarle J; Räisänen, Mika; Mäkelä, Timo; Hillamo, Risto

    2006-04-30

    Road dust forms an important component of airborne particulate matter in urban areas. In many winter cities the use of anti-skid aggregates and studded tires enhance the generation of mineral particles. The abrasion particles dominate the PM10 during springtime when the material deposited in snow is resuspended. This paper summarizes the results from three test series performed in a test facility to assess the factors that affect the generation of abrasion components of road dust. Concentrations, mass size distribution and composition of the particles were studied. Over 90% of the particles were aluminosilicates from either anti-skid or asphalt concrete aggregates. Mineral particles were observed mainly in the PM10 fraction, the fine fraction being 12% and submicron size being 6% of PM10 mass. The PM10 concentrations increased as a function of the amount of anti-skid aggregate dispersed. The use of anti-skid aggregate increased substantially the amount of PM10 originated from the asphalt concrete. It was concluded that anti-skid aggregate grains contribute to pavement wear. The particle size distribution of the anti-skid aggregates had great impact on PM10 emissions which were additionally enhanced by studded tires, modal composition, and texture of anti-skid aggregates. The results emphasize the interaction of tires, anti-skid aggregate, and asphalt concrete pavement in the production of dust emissions. They all must be taken into account when measures to reduce road dust are considered. The winter maintenance and springtime cleaning must be performed properly with methods which are efficient in reducing PM10 dust.

  11. Cause Analysis of Asphalt Concrete Pavement Disease%沥青路面病害的成因分析

    Institute of Scientific and Technical Information of China (English)

    高雪

    2013-01-01

    From raw materials selection, structure design and construction of asphalt concrete pavement, the article made a detailed description on disease types, causes and prevention measures of the asphalt concrete pavement.%  文章从沥青混凝土路面的原材料选择、结构设计、施工等方面入手,对沥青混凝土路面病害的类型、发生原因及防治措施进行详细说明。

  12. The Fuzzy Logic Model for the Prediction of Marshall Stability of Lightweight Asphalt Concretes Fabricated using Expanded Clay Aggregate

    Directory of Open Access Journals (Sweden)

    Sercan SERİN

    2014-07-01

    Full Text Available In the study, predictability of Marshall Stability (MS of light asphalt concrete that fabricated using expanded clay and had varied mix properties with Fuzzy Logic (FL were researched. With this aim, asphalt concrete samples that added expanded clay aggregate (EC in accordance with gradation determined in Highway Technical Specification, had different percentage of bitumen (POB (4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, 10%, 10.5% and unit weight (UW (1,75–1,87 (gr/cm3 were prepared and determined Marshall stabilities with Marshall test

  13. Road asphalt modifiers based on oil-resistant rubbers and products of thermal transformations of coals

    Energy Technology Data Exchange (ETDEWEB)

    Sharypov, V.I.; Kiselev, V.P.; Beregovtsova, N.G.; Bugaenko, M.B.; Kuznetsov, B.N. [Russian Academy of Sciences, Moscow (Russian Federation)

    2008-07-15

    The properties of asphalt binder modifiers prepared by dissolving butadiene-acrylonitrile rubbers and their production waste in liquid products of heat treatment of various brands of coal were studied.

  14. Multiscale imaging and characterization of the effect of mixing temperature on asphalt concrete containing recycled components.

    Science.gov (United States)

    Cavalli, M C; Griffa, M; Bressi, S; Partl, M N; Tebaldi, G; Poulikakos, L D

    2016-10-01

    When producing asphalt concrete mixture with high amounts of reclaimed asphalt pavement (RAP), the mixing temperature plays a significant role in the resulting spatial distribution of the components as well as on the quality of the resulting mixture, in terms of workability during mixing and compaction as well as in service mechanical properties. Asphalt concrete containing 50% RAP was investigated at mixing temperatures of 140, 160 and 180°C, using a multiscale approach. At the microscale, using energy dispersive X-ray spectroscopy the RAP binder film thickness was visualized and measured. It was shown that at higher mixing temperatures this film thickness was reduced. The reduction in film thickness can be attributed to the loss of volatiles as well as the mixing of RAP binder with virgin binder at higher temperatures. X-ray computer tomography was used to characterize statistically the distribution of the RAP and virgin aggregates geometric features: volume, width and shape anisotropy. In addition using X-ray computer tomography, the packing and spatial distribution of the RAP and virgin aggregates was characterized using the nearest neighbour metric. It was shown that mixing temperature may have a positive effect on the spatial distribution of the aggregates but did not affect the packing. The study shows a tendency for the RAP aggregates to be more likely distributed in clusters at lower mixing temperatures. At higher temperatures, they were more homogeneously distributed. This indicates a higher degree of blending both at microscale (binder film) and macroscale (spatial distribution) between RAP and virgin aggregates as a result of increasing mixing temperatures and the ability to quantify this using various imaging techniques.

  15. Investigating the Effects of Nanoclay and Nylon Fibers on the Mechanical Properties of Asphalt Concrete

    Directory of Open Access Journals (Sweden)

    Hasan Taherkhani

    2016-12-01

    Full Text Available This paper describes the effects of reinforcement by randomly distributed nylon fibers and addition of nanoclay on some engineering properties of a typical asphalt concrete. The properties of asphalt concrete reinforced by different percentages of 25 mm nylon fibers have been compared with those of the mixtures containing different percentages of nanoclay and those in which both the fibers and nanoclay have been included. Engineering properties, including Marshall stability, resilient modulus, dynamic creep and fatigue life have been studied. Nylon fibers have been used in different percentages of 0.1, 0.2, 0.3 and 0.4% (by the weight of total mixture, and nanoclay has been used in 2, 4 and 7% (by the weight of bitumen. It is found that the addition of fibers is more effective than the nanoclay for increasing the resistance against fatigue cracking. However, nanoclay improves the resistance of the mixture against permanent deformation better than the nylon fibers. The results also show that the mixture reinforced by 0.4% of nylon fibers and containing 7% of nanoclay has the highest resilient modulus, Marshall stability and fatigue life. However, the mixture containing only 7% of nanoclay has the highest resistance against permanent deformation.

  16. Behavior of sulfur mustard in sand, concrete, and asphalt matrices: Evaporation, degradation, and decontamination.

    Science.gov (United States)

    Jung, Hyunsook; Choi, Seungki

    2017-07-24

    The evaporation, degradation, and decontamination of sulfur mustard on environmental matrices including sand, concrete, and asphalt are described. A specially designed wind tunnel and thermal desorber in combination with gas chromatograph (GC) produced profiles of vapor concentration obtained from samples of the chemical agent deposited as a drop on the surfaces of the matrices. The matrices were exposed to the chemical agent at room temperature, and the degradation reactions were monitored and characterized. A vapor emission test was also performed after a decontamination process. The results showed that on sand, the drop of agent spread laterally while evaporating. On concrete, the drop of the agent was absorbed immediately into the matrix while spreading and evaporating. However, the asphalt surface conserved the agent and slowly released parts of the agent over an extended period of time. The degradation reactions of the agent followed pseudo first order behavior on the matrices. Trace amounts of the residual agent present at the surface were also released as vapor after decontamination, posing a threat to the exposed individual and environment.

  17. Experimental evaluation on high temperature rheological properties of various fiber modified asphalt binders

    Institute of Scientific and Technical Information of China (English)

    陈筝; 吴少鹏; 朱祖煌; 刘杰胜

    2008-01-01

    High temperature rheological properties of fiber modified asphalt binders and impact of the type and content on such properties were studied.Three types of fiber,including polyester(PET),polyacrylonitrile(PAN) and cellulose(CEL),a control content(0%) and four levels of fiber content(2%,4%,6% and 8% by total asphalt binder mass) were used with asphalt binders.The high temperature rheological properties,consisting of complex modulus(G*) and phase angle δ,were measured using SHRP’s dynamic shear rheometer(DSR) between 46-82 ℃.Experimental results indicate that the changes of G* and tan δ of fiber modified asphalt binders with the increase of test temperature tend to slow down,and the temperature susceptibility is improved obviously compared to that of original asphalt binder.Fiber modification results in the increase of rutting parameter(G*/sin δ) at high temperatures,the decrease of temperature susceptibility,and further improved high temperature performance of asphalt binder.An excellent correlation exhibits between fiber content and high temperature performance of asphalt binder.Moreover,fiber type also has different influences on the improvement of G*/sin δ,G*/sin δ of PET and PAN fiber asphalt binders are both higher than that of CEL fiber,but G*/sin δ of CEL fiber is still higher than that of original asphalt.However,there is a critical fiber content when fibers start to interact with each other.Therefore,based on the critical fiber content and economic consideration,the optimum fiber contents for various fiber-modified asphalt binders are obtained.

  18. Preparation of Flame Retardant Modified with Titanate for Asphalt Binder

    Directory of Open Access Journals (Sweden)

    Bo Li

    2014-01-01

    Full Text Available Improving the compatibility between flame retardant and asphalt is a difficult task due to the complex nature of the materials. This study explores a low dosage compound flame retardant and seeks to improve the compatibility between flame retardants and asphalt. An orthogonal experiment was designed taking magnesium hydroxide, ammonium polyphosphate, and melamine as factors. The oil absorption and activation index were tested to determine the effect of titanate on the flame retardant additive. The pavement performance test was conducted to evaluate the effect of the flame retardant additive. Oxygen index test was conducted to confirm the effect of flame retardant on flame ability of asphalt binder. The results of this study showed that the new composite flame retardant is more effective in improving the compatibility between flame retardant and asphalt and reducing the limiting oxygen index of asphalt binder tested in this study.

  19. Development of the Asphalt Modifier%沥青改性剂发展综述

    Institute of Scientific and Technical Information of China (English)

    顾绍兴; 马骏; 安会勇

    2015-01-01

    The concepts of asphalt and asphalt modifier were introduced. The asphalt modifier is usually divided into polymer type and non-polymer type. The research progress in various asphalt modifiers in recent years was introduced, and the modifying effect of various asphalt modifiers under different processes and conditions was researched. Finally, developing tendency of the asphalt modifier was put forward.%介绍了沥青及沥青改性剂的概念,通过把沥青改性剂分成聚合物沥青改性剂和非聚合物沥青改性剂两类进行讨论。讨论近些年来一些高校和研究人员对各种沥青改性剂研究的概况,研究在不同工艺和环境条件下,选用不同种类的沥青改性剂对沥青进行改性,并讨论了不同改性剂对沥青的改性效果。最后,还提出了沥青改性剂的发展方向。

  20. Addressing Infrastructure Durability and Sustainability by Self Healing Mechanisms: Recent Advances in Self Healing Concrete and Asphalt

    NARCIS (Netherlands)

    Schlangen, H.E.J.G.; Sangadji, S.

    2013-01-01

    Infrastructures cover a very broad spectrum of different materials. This paper focuses on civil engineering structures, concrete and asphalt in particular. The public demand for such infrastructures is high level of service and performance, high durability and minimum negative ecological impact. New

  1. Addressing Infrastructure Durability and Sustainability by Self Healing Mechanisms: Recent Advances in Self Healing Concrete and Asphalt

    NARCIS (Netherlands)

    Schlangen, H.E.J.G.; Sangadji, S.

    2013-01-01

    Infrastructures cover a very broad spectrum of different materials. This paper focuses on civil engineering structures, concrete and asphalt in particular. The public demand for such infrastructures is high level of service and performance, high durability and minimum negative ecological impact. New

  2. Rheological Properties of Asphalt Modified by Supramolecular UV Resistant Material-LDHs

    Institute of Scientific and Technical Information of China (English)

    WANG Jinshan; WU Shaopeng; HAN Jun; LIU Xing

    2012-01-01

    Dynamic rheological properties of asphalt modified by Supramolecular UV resistant material-layered double hydroxides(LDHs) was studied by means of the dynamic shear rheometer (DSR) test.Two typical base asphalts were chosen and modified by 2 different LDHs contents.DSR tests were performed on the original samples,samples after exposed to outdoor and samples after the artificial accelerated UV aging tests respectively to analyze the rheological properties.It is found that when the LDHs content is between 3wt% and 5wt% of asphalt weight,the high temperature performance and fatigue resistant property of the modified asphalt become better,the UV aging resistance properties are improved.

  3. 天然沥青改性沥青的表面自由能分析%Surface free energy analysis of asphalt modified with natural asphalt

    Institute of Scientific and Technical Information of China (English)

    马峰; 郝景贤; 傅珍; 汪立龙; 汪林兵

    2015-01-01

    In order to accurately evaluate the adhesion of asphalt modified with natural asphalt and aggregate,the contact angles of three liquids on the sample surface of asphalt modified with natural asphalt were measured based on sessile drop method.According to the theory of surface physical chemistry,the measuring method of polar component and dispersion component for asphalt surface free energy under the condition of room temperature was determined.The surface free energies of base asphalt and asphalts modified with different dosages of natural asphalt were calculated.The relationship between asphalt surface free energy and asphalt-aggregate adhesion grade was analyzed based on the test result by using water-boiling method.Test result shows that the surface free energies of 70 # grade A base asphalt and asphalt modified with 8% natural asphalt are 10.60,18.60 mJ ·m-2 respectively,so the surface free energy of asphalt modified with natural asphalt increases distinctly with the addition of natural asphalt.There is a good correlation between asphalt-aggregate adhesion and the surface free energy of asphalt calculated by contact angle method.The natural asphalt contains higher polar functional groups such as O, S and N etc.High contents of asphaltene and net structure can absorb the light components of base asphalt such as saturates,aromatics.The increase of surface free energy for asphalt modified with natural asphalt is attributed to the polar functional groups and the absorbing functions. 4 tabs,4 figs,23 refs.%为了准确评价天然沥青改性沥青与集料的粘附性能,采用座滴法测定了3种液体在天然沥青改性沥青试样表面的接触角,基于表面物理化学理论,确定了室温条件下沥青表面自由能极性分量和色散分量的测定方法,计算了基质沥青和不同掺量天然沥青改性沥青的表面自由能。结合水煮法试验结果,分析了沥青结合料表面自由能与沥青-集料粘附性等级的

  4. Property Analysis of Exfoliated Graphite Nanoplatelets Modified Asphalt Model Using Molecular Dynamics (MD Method

    Directory of Open Access Journals (Sweden)

    Hui Yao

    2017-01-01

    Full Text Available This Molecular Dynamics (MD simulation paper presents a physical property comparison study between exfoliated graphite nanoplatelets (xGNP modified and control asphalt models, including density, glass transition temperature, viscosity and thermal conductivity. The three-component control asphalt model consists of asphaltenes, aromatics, and saturates based on previous references. The xGNP asphalt model was built by incorporating an xGNP and control asphalt model and controlling mass ratios to represent the laboratory prepared samples. The Amber Cornell Extension Force Field (ACEFF was used with assigned molecular electro-static potential (ESP charge from NWChem analysis. After optimization and ensemble relaxation, the properties of the control and xGNP modified asphalt models were computed and analyzed using the MD method. The MD simulated results have a similar trend as the test results. The property analysis showed that: (1 the density of the xGNP modified model is higher than that of the control model; (2 the glass transition temperature of the xGNP modified model is closer to the laboratory data of the Strategic Highway Research Program (SHRP asphalt binders than that of the control model; (3 the viscosities of the xGNP modified model at different temperatures are higher than those of the control model, and it coincides with the trend in the laboratory data; (4 the thermal conductivities of the xGNP modified asphalt model are higher than those of the control asphalt model at different temperatures, and it is consistent with the trend in the laboratory data.

  5. Rutting and Fatigue Cracking Resistance of Waste Cooking Oil Modified Trinidad Asphaltic Materials

    Directory of Open Access Journals (Sweden)

    Rean Maharaj

    2015-01-01

    Full Text Available The influence of waste cooking oil (WCO on the performance characteristics of asphaltic materials indigenous to Trinidad, namely, Trinidad Lake Asphalt (TLA, Trinidad Petroleum Bitumen (TPB, and TLA : TPB (50 : 50 blend, was investigated to deduce the applicability of the WCO as a performance enhancer for the base asphalt. The rheological properties of complex modulus (G∗ and phase angle (δ were measured for modified base asphalt blends containing up to 10% WCO. The results of rheology studies demonstrated that the incremental addition of WCO to the three parent binders resulted in incremental decreases in the rutting resistance (decrease in G∗/sinδ values and increases in the fatigue cracking resistance (decrease in G∗sinδ value. The fatigue cracking resistance and rutting resistance for the TLA : TPB (50 : 50 blends were between those of the blends containing pure TLA and TPB. As operating temperature increased, an increase in the resistance to fatigue cracking and a decrease in the rutting resistance were observed for all of the WCO modified asphaltic blends. This study demonstrated the capability to create customized asphalt-WCO blends to suit special applications and highlights the potential for WCO to be used as an environmentally attractive option for improving the use of Trinidad asphaltic materials.

  6. Qualitative analysis of SBS modifier in asphalt pavements using field samples

    Science.gov (United States)

    Chi, Fengxia; Liu, Zhifei

    2017-06-01

    Series of tests are implemented to analysis the related characteristics of common asphalt and unknown asphalt mainly using Fourier Transform Infrared (FTIR) and Dynamic Shear Rheometer (DSR) for chemical compositions and rheological properties of asphalt, respectively. In addition, a series of mechanical properties were performed on asphalt mixtures, including indirect tensile strength test and three point bending test at low temperature. Experimental results indicated that compared with common asphalt, the characteristic absorption peak of the unknown asphalt are appeared at 966cm-1and 699cm-1, which are accordant with the SBS modifier. The results of DSR indicated that the unknown asphalt’s complex modulus is higher and the phase angle is lower. The mechanical tests indicated that some properties of the unknown mixture samples are increased by 24.7%∼41.8% compared with common pavement sample, like the indirect tensile strength, the bending test at low temperature and indirect tensile resilient modulus. Comprehensive analysis indicates that SBS modifier is existed in the unknown asphalt pavement.

  7. Field investigation of low-temperature cracking and stiffness moduli on selected roads with conventional and high modulus asphalt concrete

    Science.gov (United States)

    Judycki, Józef; Jaczewski, Mariusz; Ryś, Dawid; Pszczoła, Marek; Jaskuła, Piotr; Glinicki, Adam

    2017-09-01

    High Modulus Asphalt Concrete (HMAC) was introduced in Poland as a one of the solutions to the problem of rutting, type of deterioration common in the 1990s. After first encouraging trials in 2002 HMAC was widely used for heavily loaded national roads and motorways. However some concerns were raised about low-temperature cracking of HMAC. This was the main reason of the studies presented in this article were started. The article presents the comparison of performance of pavements constructed in typical contract conditions with the road bases made of HMAC and conventional asphalt concrete (AC). The field investigation was focused on the number of low-temperature cracks, bearing capacity (based on FWD test) of road sections localized in coldest region of Poland. Also load transfer efficiency of selected low-temperature cracks was assessed. FWD test confirmed lower deflections of pavements with HMAC and two times higher stiffness modulus of asphalt courses in comparison to pavements constructed with conventional AC mixtures. Relation of stiffness of asphalt layers and amount of low-temperature cracks showed that the higher stiffness modulus of asphalt layers could lead to increase of the number of low-temperature cracks. FWD test results showed that the load transfer efficiency of low-temperature cracks on pavements with HMAC presents very low values, very close to lack of load transfer. It was surprising as section with HMAC road base were aged from 2 to 5 years and presented very good bearing capacity.

  8. Development of a stress-mode sensitive viscoelastic constitutive relationship for asphalt concrete: experimental and numerical modeling

    Science.gov (United States)

    Karimi, Mohammad M.; Tabatabaee, Nader; Jahanbakhsh, H.; Jahangiri, Behnam

    2016-11-01

    Asphalt binder is responsible for the thermo-viscoelastic mechanical behavior of asphalt concrete. Upon application of pure compressive stress to an asphalt concrete specimen, the stress is transferred by mechanisms such as aggregate interlock and the adhesion/cohesion properties of asphalt mastic. In the pure tensile stress mode, aggregate interlock plays a limited role in stress transfer, and the mastic phase plays the dominant role through its adhesive/cohesive and viscoelastic properties. Under actual combined loading patterns, any coordinate direction may experience different stress modes; therefore, the mechanical behavior is not the same in the different directions and the asphalt specimen behaves as an anisotropic material. The present study developed an anisotropic nonlinear viscoelastic constitutive relationship that is sensitive to the tension/compression stress mode by extending Schapery's nonlinear viscoelastic model. The proposed constitutive relationship was implemented in Abaqus using a user material (UMAT) subroutine in an implicit scheme. Uniaxial compression and indirect tension (IDT) testing were used to characterize the viscoelastic properties of the bituminous materials and to calibrate and validate the proposed constitutive relationship. Compressive and tensile creep compliances were calculated using uniaxial compression, as well as IDT test results, for different creep-recovery loading patterns at intermediate temperature. The results showed that both tensile creep compliance and its rate were greater than those of compression. The calculated deflections based on these IDT test simulations were compared with experimental measurements and were deemed acceptable. This suggests that the proposed viscoelastic constitutive relationship correctly demonstrates the viscoelastic response and is more accurate for analysis of asphalt concrete in the laboratory or in situ.

  9. Development of a stress-mode sensitive viscoelastic constitutive relationship for asphalt concrete: experimental and numerical modeling

    Science.gov (United States)

    Karimi, Mohammad M.; Tabatabaee, Nader; Jahanbakhsh, H.; Jahangiri, Behnam

    2017-08-01

    Asphalt binder is responsible for the thermo-viscoelastic mechanical behavior of asphalt concrete. Upon application of pure compressive stress to an asphalt concrete specimen, the stress is transferred by mechanisms such as aggregate interlock and the adhesion/cohesion properties of asphalt mastic. In the pure tensile stress mode, aggregate interlock plays a limited role in stress transfer, and the mastic phase plays the dominant role through its adhesive/cohesive and viscoelastic properties. Under actual combined loading patterns, any coordinate direction may experience different stress modes; therefore, the mechanical behavior is not the same in the different directions and the asphalt specimen behaves as an anisotropic material. The present study developed an anisotropic nonlinear viscoelastic constitutive relationship that is sensitive to the tension/compression stress mode by extending Schapery's nonlinear viscoelastic model. The proposed constitutive relationship was implemented in Abaqus using a user material (UMAT) subroutine in an implicit scheme. Uniaxial compression and indirect tension (IDT) testing were used to characterize the viscoelastic properties of the bituminous materials and to calibrate and validate the proposed constitutive relationship. Compressive and tensile creep compliances were calculated using uniaxial compression, as well as IDT test results, for different creep-recovery loading patterns at intermediate temperature. The results showed that both tensile creep compliance and its rate were greater than those of compression. The calculated deflections based on these IDT test simulations were compared with experimental measurements and were deemed acceptable. This suggests that the proposed viscoelastic constitutive relationship correctly demonstrates the viscoelastic response and is more accurate for analysis of asphalt concrete in the laboratory or in situ.

  10. Performance of the heavy fraction of pyrolysis oil derived from waste printed circuit boards in modifying asphalt.

    Science.gov (United States)

    Yang, Fan; Sun, Shuiyu; Zhong, Sheng; Li, Shenyong; Wang, Yi; Wu, Jiaqi

    2013-09-15

    The focus of this research was the development of efficient and affordable asphalt modifiers. Pyrolysis oil was produced as a byproduct from the pyrolysis of waste printed circuit boards (WPCBs). The high boiling point fraction was separated from the pyrolysis oil through distillation and is referred to as the heavy fraction of pyrolysis oil (HFPO). The HFPO was tested as an asphalt modifier. Three asphalt modifiers were tested: HFPO; styrene-butadiene rubber (SBR); and HFPO + SBR (1:1). The physical properties and road performance of the three modified asphalts were measured and evaluated. The results have shown that when the amount of modifier was less than 10%, the HFPO modified asphalt had the highest softening point of the three. The dynamic stability (DS) and water resistance of the asphalt mixture with the HFPO modified asphalt was 10,161 cycles/mm and 87.2%, respectively. The DS was much larger than for the HFPO + SBR and SBR modified asphalt mixtures. These results indicate that using HFPO as an asphalt modifier has significant benefits not only for road engineering but also for resource recycling.

  11. Discrete Element Modeling of Asphalt Concrete Cracking Using a User-defined Tlree-dimensional Micromechanical Approach

    Institute of Scientific and Technical Information of China (English)

    CHEN Jun; PAN Tongyan; HUANG Xiaoming

    2011-01-01

    We established a user-defined micromechanical model using discrete element method (DEM) to investigate the cracking behavior of asphalt concrete (AC).Using the “Fish” language provided in the particle flow code in 3-Demensions (PFC3D),the air voids and mastics in asphalt concrete were realistically built as two distinct phases.With the irregular shape of individual aggregate particles modeled using a clump of spheres of different sizes,the three-dimensional (3D) discrete element model was able to account for aggregate gradation and fraction.Laboratory uniaxial complex modulus test and indirect tensile strength test were performed to obtain input material parameters for the numerical simulation.A set of the indirect tensile test were simulated to study the cracking behavior of AC at two levels of temperature,i e,-10 ℃ and 15 ℃.The predicted results of the numerical simulation were compared with laboratory experimental measurements.Results show that the 3D DEM model is able to predict accurately the fracture pattern of different asphalt mixtures.Based on the DEM model,the effects of air void content and aggregate volumetric fraction on the cracking behavior of asphalt concrete were evaluated.

  12. Black curves and creep behaviour of crumb rubber modified binders containing warm mix asphalt additives

    Science.gov (United States)

    Gallego, Juan; Rodríguez-Alloza, Ana María; Giuliani, Felice

    2016-08-01

    Warm mix asphalt (WMA) is a new research topic in the field of road pavement materials. This technology allows lower energy consumption and greenhouse gas (GHG) emissions by reducing compaction and placement temperatures of the asphalt mixtures. However, this technology is still under study, and the influence of the WMA additives has yet to be investigated thoroughly and clearly identified, especially in the case of crumb rubber modified (CRM) binders.

  13. Research on pavement performance of steel deck epoxy asphalt pouring concrete%钢桥面环氧沥青浇筑式混凝土铺装路用性能研究

    Institute of Scientific and Technical Information of China (English)

    崔晓波; 李超源; 邵强

    2014-01-01

    Through different binder contents flow detection selected suitable binder contents, and identified the suitable mixing time of mixture under the conditions of 10% binder content, the high and low temperature experiment results showed that, the low temperature performance of epoxy asphalt pouring asphalt mixture better than ordinary roller type epoxy asphalt concrete, and its low temperature properties little effect by mixing time, compared with common modified asphalt, epoxy asphalt could significantly improve the high temperature stability of pouring asphalt mixture.%通过不同结合料含量流动性检测选取了适宜的结合料用量,并确定了10%结合料用量条件下混合料适宜的拌和时间,高低温试验结果表明,环氧沥青浇筑式沥青混合料的低温性能优于普通碾压式环氧沥青混凝土,且其低温性能受拌和时间影响不大,与普通改性沥青相比,环氧沥青能够显著改善浇筑式沥青混合料的高温稳定性。

  14. Improving Asphalt Mixture Performance by Partially Replacing Bitumen with Waste Motor Oil and Elastomer Modifiers

    Directory of Open Access Journals (Sweden)

    Sara Fernandes

    2017-08-01

    Full Text Available The environmental concern about waste generation and the gradual decrease of oil reserves has led the way to finding new waste materials that may partially replace the bitumens used in the road paving industry. Used motor oil from vehicles is a waste product that could answer that demand, but it can also drastically reduce the viscosity, increasing the asphalt mixture’s rutting potential. Therefore, polymer modification should be used in order to avoid compromising the required performance of asphalt mixtures when higher amounts of waste motor oil are used. Thus, this study was aimed at assessing the performance of an asphalt binder/mixture obtained by replacing part of a paving grade bitumen (35/50 with 10% waste motor oil and 5% styrene-butadiene-styrene (SBS as an elastomer modifier. A comparison was also made with the results of a previous study using a blend of bio-oil from fast pyrolysis and ground tire rubber modifier as a partial substitute for usual PG64-22 bitumen. The asphalt binders were tested by means of Fourier infrared spectra and dynamic shear rheology, namely by assessing their continuous high-performance grade. Later, the water sensitivity, fatigue cracking resistance, dynamic modulus and rut resistance performance of the resulting asphalt mixtures was evaluated. It was concluded that the new binder studied in this work improves the asphalt mixture’s performance, making it an excellent solution for paving works.

  15. Laboratory Study on Properties of Diatomite and Basalt Fiber Compound Modified Asphalt Mastic

    Directory of Open Access Journals (Sweden)

    Yongchun Cheng

    2017-01-01

    Full Text Available In order to improve the performance of asphalt mastic, some researchers have added diatomite or basalt fiber as a modifier to the asphalt mastic, and the results show that some properties of the asphalt mastic were improved. For the simultaneous addition of diatomite and basalt fiber, two kinds of modifier, compound modified asphalt mastic had not been reported; in this paper, thirteen groups of diatomite and basalt fiber (DBFCMAM compound modified asphalt mastic with different content were prepared to study the performance. Softening point, cone penetration, viscosity, and DSR tests were conducted, for the high temperature performance evaluation of DBFCMAM, whereas force ductility and BBR tests were used in the low temperature performance study of the DBFCMAM. The results demonstrated that the high temperature performance of DBFCMAM was increased; moreover, the low temperature performance of DBFCMAM improved by diatomite and basalt fiber according to the results of the force ductility test; however, the conclusion of the BBR test data was inconsistent with the force ductility test. In summary, the high temperature and low temperature properties of DBFCMAM had been improved.

  16. 沥青砼路面裂缝预防措施%Prevention Measures on the Asphalt Concrete Pavement Crevices

    Institute of Scientific and Technical Information of China (English)

    贾陇春

    2014-01-01

    文章简单介绍了沥青砼路面裂缝的集中类型,对沥青砼路面产生裂缝的原因进行了分析,着重提出了相应的沥青砼路面裂缝预防措施。希望能进一步延长沥青砼路面的使用寿命,提升路面服务质量,为工程技术人员提供一定的参考和借鉴。%This paper briefly introduces the main types of asphalt concrete pavement crevices and analyzed the causes of crevices, focusing on corresponding prevention measures. By this, the author hoped to further extend the service life of asphalt concrete pavement and improved the pavement quality, providing a reference for engineering and technical personnel.

  17. Investigating the Properties of Asphalt Concrete Containing Glass Fibers and Nanoclay

    OpenAIRE

    Hasan Taherkhani

    2016-01-01

    The performance of asphaltic pavements during their service life is highly dependent on the mechanical properties of the asphaltic layers. Therefore, in order to extend their service life, scientists and engineers are constantly trying to improve the mechanical properties of the asphaltic mixtures. One common method of improving the performance of asphaltic mixtures is using different types of additives. This research investigated the effects of reinforcement by randomly distributed glass fib...

  18. On the representative volume element of asphalt concrete at low temperature

    Science.gov (United States)

    Marasteanu, Mihai; Cannone Falchetto, Augusto; Velasquez, Raul; Le, Jia-Liang

    2016-08-01

    The feasibility of characterizing asphalt mixtures' rheological and failure properties at low temperatures by means of the Bending Beam Rheometer (BBR) is investigated in this paper. The main issue is the use of thin beams of asphalt mixture in experimental procedures that may not capture the true behavior of the material used to construct an asphalt pavement.

  19. 短切沥青碳纤维混凝土马歇尔试验研究%Marshall test research on chopped asphalt carbon fiber concrete

    Institute of Scientific and Technical Information of China (English)

    张明德

    2012-01-01

    The paper discusses the impact of chopped asphalt carbon fiber on asphalt concrete,compares the changing situation of various indicators of Marshall test,and determines the mixing proportion of chopped asphalt carbon fiber concrete,which has provided certain basis for the construction and design of chopped asphalt carbon fiber concrete.%讨论了短切沥青碳纤维对沥青混凝土马歇尔试验的影响,比较了马歇尔试验各项技术指标的变化情况,确定了短切沥青碳纤维混凝土的配比,为指导短切沥青碳纤维混凝土的设计和施工提供依据。

  20. SIMULATION OF TEMPERATURE AND TRANSPORT LOAD IMPACT ON FORMATION AND DEVELOPMENT OF CRACKS ON ASPHALT-CONCRETE ROAD SURFACES

    Directory of Open Access Journals (Sweden)

    I. Melnikova

    2012-01-01

    Full Text Available An analysis of statistical data has shown that about 60 % of all types of road surface destructions and damages in the Republic of Belarus are attributed to cracks (separate, frequent and cracks network. The process of cracks formation in the asphalt concrete pavement is rather complicated and it is affected by a number of factors. The most important and determining factors are character and value of traffic loads, temperature action, road pavement structure, properties of materials used for its layers. Some regularities of the cracks formation and development in the asphalt-concrete layers of the pavement have been established on the basis of the physical and mathematical modeling. Application of a finite  element  method for  calculations  has made it possible to determine  numerical values of compressive and tensile stresses arising due to temperature action and traffic load, deflection of road pavement constructive layers. The paper contains recommendations for a road pavement design and repair of asphalt-concrete pavements which have been made on the basis of the obtained data analysis.

  1. Calculation of the temperature of asphalt concrete at making the joints of multilane road pavement of non-rigid type

    Directory of Open Access Journals (Sweden)

    Giyasov Botir Iminzhonovich

    2015-03-01

    Full Text Available The construction quality of road surface of non-rigid type essentially depend on providing the temperature regimes in the process of laying and packing of hot asphalt concrete mixtures. In order to provide the required characteristics of asphalt concrete due to the surface width it is necessary to provide the temperature regimes of hot asphalt concrete mixture in the zones of lane connection. The hot mixture is promptly cooling right after laying within several minutes, which results, according to the construction technology and the specific conditions of work production, in temperature abuse of the mixture at joints of the lanes at packing. The authors present the analysis of the technology of arranging multilane road surface by one paver with the possibility of heating the surface lane edge with the temperature of the adjacent lane. The results of the studies of the production conditions effect on the temperature of edge heating of the previously laid lanes, and the time required to achieve the maximum heating temperature depending on the relative thickness of coating layers.

  2. Effect of Xenon Lamp Accelerated Aging on the Performance of Asphalt Concrete%氙灯加速老化对沥青混合料性能的影响

    Institute of Scientific and Technical Information of China (English)

    何文华; 郭韦韦; 杨群

    2012-01-01

    Asphalt concretes with three gradation types and four kinds of asphalts are aged with the xenon lamp to study the performance of modified asphalt exposed to sunlight. Marshall stability and flow value and the change are used to evaluate respectively the high temperature stability and anti-ultraviolet aging ability. The results show that lignin fiber can improve high temperature stability and anti-ultraviolet aging ability of asphalt concretes. High temperature stability and anti-ultraviolet aging ability of asphalt concretes with different gradation types is different. High temperature stability and ultraviolet light resistance aging performance of different gradation types of asphalt mixture have differences: influence of dense gradation is the smallest, half-open gradation is the second smallest, and open gradation the worst. These features can provide helpful reference for asphalt mixture ultraviolet aging research, and provide the evaluation and selectionof the asphalt mixture in the western region of ultraviolet radiation.%为考察沥青混合料的性能受光照的影响,对三种级配类型及四种沥青的沥青混合料进行氙灯加速老化试验.用马歇尔稳定度和流值、紫外光老化前后马歇尔稳定度和流值的变化分别评价沥青混合料的高温稳定性和抗紫外光老化能力.结果表明木质素纤维能够有效改善沥青混合料的高温稳定性及抗紫外光老化性能.不同级配类型的沥青混合料的高温稳定性和抗紫外光老化性能各有差异:密级配受影响程度最小,半开级配次之,开级配最差.这些特点可以为沥青混合料紫外光老化的研究提供有益的参考,也为紫外线辐射强烈的西部地区沥青混合料的评价与选择提供依据.

  3. Characterization of long term field aging of polymer modified bitumen in porous asphalt

    NARCIS (Netherlands)

    Vliet, D. van; Erkens, S.; Leegwater, G.A.

    2012-01-01

    The effect of long term field aging on different types of polymer modified binders used in two-layer porous asphalt is studied using different test methods. Chemical and rheological tests are performed on samples taken from road sections at different moments in time in search of trends in long term

  4. Characterization of long term field aging of polymer modified bitumen in porous asphalt

    NARCIS (Netherlands)

    Vliet, D. van; Erkens, S.; Leegwater, G.A.

    2012-01-01

    The effect of long term field aging on different types of polymer modified binders used in two-layer porous asphalt is studied using different test methods. Chemical and rheological tests are performed on samples taken from road sections at different moments in time in search of trends in long term

  5. A novel technique for the production of cool colored concrete tile and asphalt shingle roofing products

    Energy Technology Data Exchange (ETDEWEB)

    Levinson, Ronnen; Akbari, Hashem; Berdahl, Paul; Wood, Kurt; Skilton, Wayne; Petersheim, Jerry

    2009-11-20

    The widespread use of solar-reflective roofing materials can save energy, mitigate urban heat islands and slow global warming by cooling the roughly 20% of the urban surface that is roofed. In this study we created prototype solar-reflective nonwhite concrete tile and asphalt shingle roofing materials using a two-layer spray coating process intended to maximize both solar reflectance and factory-line throughput. Each layer is a thin, quick-drying, pigmented latex paint based on either acrylic or a poly(vinylidene fluoride)/acrylic blend. The first layer is a titanium dioxide rutile white basecoat that increases the solar reflectance of a gray-cement concrete tile from 0.18 to 0.79, and that of a shingle surfaced with bare granules from 0.06 to 0.62. The second layer is a 'cool' color topcoat with weak near-infrared (NIR) absorption and/or strong NIR backscattering. Each layer dries within seconds, potentially allowing a factory line to pass first under the white spray, then under the color spray. We combined a white basecoat with monocolor topcoats in various shades of red, brown, green and blue to prepare 24 cool color prototype tiles and 24 cool color prototypes shingles. The solar reflectances of the tiles ranged from 0.26 (dark brown; CIELAB lightness value L* = 29) to 0.57 (light green; L* = 76); those of the shingles ranged from 0.18 (dark brown; L* = 26) to 0.34 (light green; L* = 68). Over half of the tiles had a solar reflectance of at least 0.40, and over half of the shingles had a solar reflectance of at least 0.25.

  6. Predicting the Dynamic Behavior of Asphalt Concrete Using Three-dimensional Discrete Element Method

    Institute of Scientific and Technical Information of China (English)

    CHEN Jun; PAN Tongyan; CHEN Jingya; HUANG Xiaoming; LU Yang

    2012-01-01

    A user-defined three-dimensional (3D) discrete element model was presented to predict the dynamic modulus and phase angle of asphalt concrete (AC).The 3D discrete element method (DEM) model of AC was constructed employing a user-defined computer program developed using the "Fish" language in PFC3D.Important microstructural features of AC were modeled,including aggregate gradation,air voids and mastic.The irregular shape of aggregate particle was modeled using a clump of spheres.The developed model was validated through comparing with experimental measurements and then used to simulate the cyclic uniaxial compression test,based on which the dynamic modulus and phase angle were calculated from the output stressstrain relationship.The effects of air void content,aggregate stiffness and volumetric fraction on AC modulus were further investigated.The experimental results show that the 3D DEM model is able to accurately predict both dynamic modulus and phase angle of AC across a range of temperature and loading frequencies.The userdefined 3D model also demonstrated significant improvement over the general existing two-dimensional models.

  7. Causes of the Abnormal Seepage Field in a Dam with Asphaltic Concrete Core

    Institute of Scientific and Technical Information of China (English)

    Jiafa Zhang; Jinlong Wang; Haodong Cui

    2016-01-01

    ABSTRACT:Asphaltic concrete core (ACC) dams are widely built in China. Many ACC dams perform well, but others have experienced significant leakage including the case in western China studied herein. A numerical model of saturated-unsaturated water flow was adapted to simulate the seepage through the dam. By comparing the normal and abnormal seepage fields under different conditions, the main causes for the actual abnormal seepage field were identified and attributed to a defect in the ACC and an unintended, low permeability layer (LPL) in the transition zone (TZ) and the downstream dam shell. These conclusions are consistent with the situation and performance of the dam. Inadequate ACC con-struction processes might have caused defects in the ACC. An abrupt change of the ACC thickness probably induced stress concentrations and caused the ACC to fail. Material sources for the TZ and dam shell were complex and varied from specifications, and soil gradation for the TZ was inadequately controlled. In particular, tests show that the permeability varies over large ranges in these two parts of the dam. An unexpected LPL probably exists in both areas, and extends continuously.

  8. Seismic joint analysis for non-destructive testing of asphalt and concrete slabs

    Science.gov (United States)

    Ryden, N.; Park, C.B.

    2005-01-01

    A seismic approach is used to estimate the thickness and elastic stiffness constants of asphalt or concrete slabs. The overall concept of the approach utilizes the robustness of the multichannel seismic method. A multichannel-equivalent data set is compiled from multiple time series recorded from multiple hammer impacts at progressively different offsets from a fixed receiver. This multichannel simulation with one receiver (MSOR) replaces the true multichannel recording in a cost-effective and convenient manner. A recorded data set is first processed to evaluate the shear wave velocity through a wave field transformation, normally used in the multichannel analysis of surface waves (MASW) method, followed by a Lambwave inversion. Then, the same data set is used to evaluate compression wave velocity from a combined processing of the first-arrival picking and a linear regression. Finally, the amplitude spectra of the time series are used to evaluate the thickness by following the concepts utilized in the Impact Echo (IE) method. Due to the powerful signal extraction capabilities ensured by the multichannel processing schemes used, the entire procedure for all three evaluations can be fully automated and results can be obtained directly in the field. A field data set is used to demonstrate the proposed approach.

  9. European project RE-ROAD: round robin test on extraction and recovery methods for Reclaimed Asphalts with Polymer modified Bitumens

    OpenAIRE

    MOUILLET, Virginie; PIERARD, Nathalie; Mollenhauer, Konrad; GINOUX, Marc Stéphane; Gabet, Thomas; Farcas, Fabienne; MIRSKI, Krzysztof; KEMPERLE, Ema

    2012-01-01

    The recycling of Reclaimed Asphalt (RA) in new hot-mix asphalt (HMA) is a common practice throughout Europe. However, Reclaimed Asphalts (RA) are complex materials and the use of significant proportions of RA involves a more accurate control of their characteristics. This is an essential step for asphalt mix design and a key factor to obtain good performances. At this time there is clearly a lack of knowledge and adequate test methods to analyse RA with Polymer modified Bitumens (PmBs). The p...

  10. Shear resistance properties of TPS modified bitumen binders and asphalt mixtures

    Institute of Scientific and Technical Information of China (English)

    曹庭维; 吴少鹏; 刘聪慧; 张涛

    2008-01-01

    Shear resistance properties of the virgin bitumen and modified bitumen binders with Tafpack Super(TPS) modifier and SBS modified bitumen were discussed.Dynamic shear rheometer(DSR) was used to measure the laboratory creep data for these binders over a wide range of constant shear stresses at 20 ℃ to characterize the shear creep behaviors of all kinds of asphalt binders,and the rutting test system was used to investigate the permanent deformation of porous asphalt mixtures using the above bitumen binders for a fixed compressive stress.The shear strain rate and shear creep modulus were used to characterize the shear creep behavior of the TPS modified bitumen,and the rutting test results were used to show the consistency of porous asphalt mixtures with the bitumen binders.Results indicate that a distinction of shear creep strain can be made among different contents of TPS modified bitumen at the same stress level,where the shear creep strain-time response curve of the SBS modified bitumen binder is between the curves of the 8% TPS and 12% TPS modified bitumen binders.The shear strain rate and the shear creep modulus of the TPS modified bitumen binders are obtained to compare with those of the SBS modified bitumen binder which results in the same trend as the shear creep strain-time response curve.Permanent deformation results of all the porous asphalt mixtures from the rutting test show reasonable agreement with the findings of the shear strain rates and shear creep modulus over the range of shear stress levels.

  11. Validation of a dynamic modulus predictive equation on the basis of spanish asphalt concrete mixtures

    Directory of Open Access Journals (Sweden)

    Mateos, A.

    2015-03-01

    Full Text Available Dynamic modulus is defined as the ratio of peak cyclic stress to peak cyclic strain under harmonic loading. It is one of the most important properties of asphalt mixtures, since it determines the strain response characteristics as a function of loading rate and temperature. Different simplified models exist that can predict this variable from mixture composition and binder rheological data, with Witczak and Hirsh models being the most widely accepted. These models have been evaluated in the present study, on the basis of 352 data points from eight asphalt concrete mixtures that were tested between −5 and 60 °C. A new model is also formulated which improves predictions of the previous ones for Spanish mixtures, even though it is a relatively simple equation that requires very limited binder rheological data compared to Witczak and Hirsch models.El módulo dinámico es la relación entre los picos de tensión y deformación bajo carga armónica. Es una de las propiedades más importantes de las mezclas bituminosas, ya que determina la respuesta deformacional en función de la velocidad de carga y la temperatura. Existen diferentes modelos simplificados que permiten predecir esta variable a partir de la composición de la mezcla y de las características reológicas del betún, siendo los de Witczak y el de Hirsch los más ampliamente aceptados. Dichos modelos han sido evaluados en el presente estudio a partir de 352 puntos procedentes de ocho mezclas tipo hormigón bituminoso que fueron ensayadas entre −5 y 60 °C. Así mismo, se ha formulado un nuevo modelo que mejora las predicciones de los anteriores para las mezclas españolas, aun tratándose de una ecuación relativamente simple que requiere una mínima información reológica del betún en comparación con los modelos de Witczak y Hirsch.

  12. Performance Evaluation of Crumb Rubber Modified Stone Mastic Asphalt Pavement in Malaysia

    Directory of Open Access Journals (Sweden)

    Nuha Salim Mashaan

    2013-01-01

    Full Text Available To prevent pavement distresses there are various solutions such as adopting new mix designs or utilisation of asphalt additives. The primary aim of this study was to investigate the effect of adding crumb tyre rubber as an additive to SMA mixture performance properties. This study investigated the essential aspects of modified asphalt mixtures in order to better understand the influence of CRM modifiers on volumetric, mechanical, and stiffness properties of SMA mixture. In this study, virgin bitumen 80/100 penetration grade was used, modified with crumb rubber (CRM at five different modification levels, namely, 6%, 12%, 16%, and 20%, respectively, by weight of the bitumen. The appropriate amount of the added CRM was found to be 12% by weight of bitumen. This percentage results in the maximum level of stability. The resilient modulus (Mr of modified SMA samples including different percentages of CRM was obviously higher in comparison with that of unmodified samples.

  13. Experimental evaluation of high performance base course and road base asphalt concrete with electric arc furnace steel slags.

    Science.gov (United States)

    Pasetto, Marco; Baldo, Nicola

    2010-09-15

    The paper presents the results of a laboratory study aimed at verifying the use of two types of electric arc furnace (EAF) steel slags as substitutes for natural aggregates, in the composition of base course and road base asphalt concrete (BBAC) for flexible pavements. The trial was composed of a preliminary study of the chemical, physical, mechanical and leaching properties of the EAF steel slags, followed by the mix design and performance characterization of the bituminous mixes, through gyratory compaction tests, permanent deformation tests, stiffness modulus tests at various temperatures, fatigue tests and indirect tensile strength tests. All the mixtures with EAF slags presented better mechanical characteristics than those of the corresponding asphalts with natural aggregate and satisfied the requisites for acceptance in the Italian road sector technical standards, thus resulting as suitable for use in road construction.

  14. Technical and economic efficiency of sulphur-modified asphalt concretes ТЕХНИКО-ЭКОНОМИЧЕСКАЯ ЭФФЕКТИВНОСТЬ ПРИМЕНЕНИЯ СЕРОАСФАЛЬТОБЕТОНОВ

    Directory of Open Access Journals (Sweden)

    Gladkikh Vitaliy Aleksandrovich

    2013-04-01

    Full Text Available The authors have proven that sulphur-modified asphalts can be efficiently applied in road building. The authors’ conclusions are based on the analysis of their laboratory research findings.In the article, the authors provide their methodology for design of the sulphur-modified asphalt concrete. The core point of the methodology proposed by the authors consists in the equality of volumes of the oil bitumen in the benchmark composition of the asphalt concrete and in the composite binder containing the bitumen and sulphur modifier.The authors have also analyzed the economic efficiency of modifying the bitumen by the sulphur modifier. The analysis is based on identification of difference between the value of the sulphur modifier that contains the emission neutralization agent instead of the oil bitumen, en expensive component of the asphalt concrete.На основании анализа результатов лабораторных исследований обоснована эффективность использования сероасфальтобетона в дорожном строительстве.Представлена методика проектирования сероасфальтобетона, в основу которой положено равенство объемов нефтяного битума базового состава асфальтобетона и вяжущей композиционной смеси, содержащей битум и серный модификатор.Вычислен экономический эффект модифицирования битума серным модификатором. Расчет основан на определении разницы в стоимости серного модификатора, содержащего нейтрализатор эмиссии, замещающего дорогостоящий компонент асфа

  15. Influence of Aging and Water Enroach on Permeable Asphalt Concrete%多孔沥青混合料老化及水稳定性研究

    Institute of Scientific and Technical Information of China (English)

    张兴梅; 徐聪

    2015-01-01

    By specimens aging impact assessment permeable asphalt concrete pavement under dif-ferent conditions,different degrees of water against and compare different maximum nominal particle size gradation on engineering properties of difference.The results show that the indirect tensile strength,stabil-ity,resilience modulus,strength and other engineering properties after aging PAC specimens are showing an increasing trend,of which the best high viscosity modified asphalt,SBS modified asphalt,followed by 70 straight distilled bitumen minimum.Road test site core drilling specimens aged 60 ℃ viscosity index higher than the results of laboratory four days of aging,but showing a similar trend,display scene PAC pavement aging situation is obvious,and the use of high viscosity modified asphalt will not only help strength increase,but also slow the aging rate.%通过对试件进行不同程度老化评估透水沥青混凝土路面在不同水侵害条件下的影响,并比较不同最大公称粒径的级配在工程性质上的差异。结果显示,PAC 试件老化后的间接抗拉强度、稳定度、回弹模量等工程性质强度都呈现增加趋势,其中以高黏度改性沥青最佳,SBS 改性沥青次之,70号直馏沥青最低。试验路现场钻芯试件的60℃黏度老化指数高于实验室4 d 老化的结果,但呈现出相近趋势,显示现场 PAC 路面老化情形明显,且使用黏度较高的改性沥青不但有助于强度提升,更可以减缓其老化速度。

  16. Dynamic Mechanical Characterizations and Road Performances of Flame Retardant Asphalt Mortars and Concretes

    Institute of Scientific and Technical Information of China (English)

    QIN Xiantao; ZHU Siyue; LI Zuzhong; CHEN Shuanfa

    2015-01-01

    To research the dynamic mechanical properties and road performances of flame retardant asphalt mortars and mixtures, four different asphalt mortars/mixtures were prepared: a reference group and three asphalt mortars/mixtures containing composite lfame retardant materials (M-FRs) of different proportions. Temperature sweep, frequency sweep, repeated creep test, force ductility test and bending beam rheological test were carried out to research the dynamic mechanical properties of asphalt mortars containing M-FRs; wheel-tracking test, low-temperature bending test and freeze-thaw split test were used to study the road performances of asphalt mixtures containing M-FRs. The results show that high-temperature performances of the three lfame retardant asphalt mortars improve greatly, while low-temperature cracking resistances decline. Both high-temperature performances and water stabilities of asphalt mixtures containing M-FRs are quite good and exceed the speciifcation requirements. However, their low-temperature performances decline in different degrees. In summary, besides their good lfame retardancy, the lfame retardant asphalt mortars and mixtures also exhibit acceptable road performance.

  17. Asphalt modified with nonmetals separated from pulverized waste printed circuit boards.

    Science.gov (United States)

    Guo, Jiuyong; Guo, Jie; Wang, Shifeng; Xu, Zhenming

    2009-01-15

    Nonmetals separated from pulverized waste printed circuit boards (PCBs) were reused as a new modifier to improve the performance of asphalt. The classical and rheological properties of unmodified asphalt and non-metal-modified asphalt (NMA) were determined. Specifically, the influence of nonmetals content and particle size on these properties has been studied. When the nonmetals content was 25 wt% and the particle size group was 0.07-0.09 mm, the NMA had a viscosity of 1225 cP at 135 degrees C, a penetration of 53.7 dmm at 15 degrees C, a ring and ball softening point of 54 degrees C, a ductility of 43.5 cm at 15 degrees C, a G*/sin delta of 3995.27 Pa at 60 degrees C, and an upper limit temperature (G*/sin delta = 1 kPa) of 69.4 degrees C, all of which showed that the high temperature performance of asphalt was improved significantly. Therefore, this study gives a fundamental understanding of NMA and represents a novel attempt to deal with the fast increasing quantities of nonmetals from waste PCBs, which is significant from an environmental and economic standpoint.

  18. Operational properties of nanomodified stone mastic asphalt

    Directory of Open Access Journals (Sweden)

    Inozemtsev Sergey Sergeevich

    2015-03-01

    Full Text Available In order to prolong the lifetime and to improve the quality of pavements made of asphalt concrete it is necessary to apply innovative solutions in the process of design of such building materials. In order to solve the problem of low durability of asphalt concrete a modifier was proposed, which consists of diatomite, iron hydroxide sol (III and silica sol. Application of the diatomite with nanoscale layer of nanomodifier allows getting a stone mastic asphalt, which has high values of physical and mechanical properties and allows refusing from expensive stabilizing additive. Mineral filler was replaced by diatomite, which has been modified by iron hydroxide sol (III and silica sol. Modified diatomite allows sorption of bitumen and increase the cohesive strength and resistance to shear at positive temperatures. The modified asphalt has higher resistance to rutting at high temperature, abrasion resistance at low temperature and impact of climatic factors: alternate freezing and thawing, wetting-drying, UV and IR radiations. It is achieved by formation of solid and dense bitumen film at the phase interface and controlling the content of light fractions of the bitumen. The modifier consists of sol of iron hydroxide, which blocks the oxidation and polymerization of bitumen during operation. The proposed material allows controlling the initial structure formation of stone mastic asphalt. It was shown that modern test methods allow assessing the durability of asphalt in the design phase compositions.

  19. Fatigue Properties of Layered Double Hydroxides Modified Asphalt and Its Mixture

    Directory of Open Access Journals (Sweden)

    Xing Liu

    2014-01-01

    Full Text Available This study investigated the influence of layered double hydroxides (LDHs on the fatigue properties of asphalt mixture. In this paper, different aging levels (thin film oven test (TFOT and ultraviolet radiation aging (UV aging for short of bitumen modified with various mass ratios of the LDHs were investigated. The TFOT and UV aging process were used to simulate short-term field thermal-oxidative aging and long-term field light UV aging of bitumen, respectively. The influences of LDHs on the fatigue properties of LDHs were evaluated by dynamic shear rheometer (DSR and indirect tensile fatigue test. Results indicated that the introduction of LDHs could change the fatigue properties of bitumen under a stress control mode. The mixture with modified bitumen showed better fatigue resistance than the mixture with base bitumen. The results illustrated that the LDHs would be alternative modifiers used in the bitumen to improve the lifetime of asphalt pavements.

  20. Clogging evaluation of porous asphalt concrete cores in conjunction with medical x-ray computed tomography

    Science.gov (United States)

    Su, Yu-Min; Hsu, Chen-Yu; Lin, Jyh-Dong

    2014-03-01

    This study was to assess the porosity of Porous Asphalt Concrete (PAC) in conjunction with a medical X-ray computed tomography (CT) facility. The PAC was designed as the surface course to achieve the target porosity 18%. There were graded aggregates, soils blended with 50% of coarse sand, and crushed gravel wrapped with geotextile compacted and served as the base, subbase, and infiltration layers underneath the PAC. The test site constructed in 2004 is located in Northern of Taiwan in which the daily traffic has been light and limited. The porosity of the test track was investigated. The permeability coefficient of PAC was found severely degraded from 2.2×10-1 to 1.2×10-3 -cm/sec, after nine-year service, while the permeability below the surface course remained intact. Several field PAC cores were drilled and brought to evaluate the distribution of air voids by a medical X-ray CT nondestructively. The helical mode was set to administrate the X-ray CT scan and two cross-sectional virtual slices were exported in seconds for analyzing air voids distribution. It shows that the clogging of voids occurred merely 20mm below the surface and the porosity can reduce as much about 3%. It was also found that the roller compaction can decrease the porosity by 4%. The permeability reduction in this test site can attribute to the voids of PAC that were compacted by roller during the construction and filled by the dusts on the surface during the service.

  1. 透水沥青混合料的热物特性与热阻功能%Thermophysical properties and thermal resistance function of permeable asphalt concrete

    Institute of Scientific and Technical Information of China (English)

    蒋玮; 沙爱民; 裴建中; 王振军

    2012-01-01

    In order to research thermophysical properties of permeable asphalt concrete,the indexes such as thermal conductivity,specific heat capacity and thermal diffusivity was computational researched between permeable asphalt and density graded asphalt concrete based on thermodynamic theory,the relationships between thermophysical properties of permeable asphalt concrete with air void moisture content were analyzed;indoor irradiation experiment was designed for determination the temperature change of PAC AC specimens.Theoretical calculation results indicate that permeable asphalt concrete is reduced by 20% with thermal conductivity,10% with thermal diffusivity,which is compared with density graded asphalt concrete;indoor temperature measurement results indicate that compared with density graded asphalt the temperature is decreased by 2-2.5℃ in the surface and 3-3.5℃ in the bottom of permeable asphalt concrete specimen,shows that permeable asphalt has function of thermal resistance,has strong resistant ability for the temperature load variation.Theoretical calculation results were verified.%为研究透水沥青混合料的热物性,基于热力学理论计算比较了透水沥青混合料和密级配沥青混合料的热导率、比热容、热扩散率等指标,并对透水沥青混合料的热物性指标与空隙率、含水率的关系展开分析;通过设计室内光照试验,测得相同的传热条件下两种材料表面和底部的温度变化。理论计算结果表明同密级配沥青混合料相比,透水沥青混合料的热导率降低约20%,热扩散率降低约10%;室内温度测试结果显示,透水沥青混合料试件表面较密级配沥青混合料试件温度低2~2.5℃,底部温度低3~3.5℃,说明透水沥青混合料具有热阻功能,对气温荷载变化的抵抗能力较强,验证了理论计算结果。

  2. Evaluation of the rheological behavior of asphaltic binder modified with zeolite material

    Energy Technology Data Exchange (ETDEWEB)

    Silveira, E.M. da; Sant' ana, Hosiberto B.; Soares, Sandra A.; Soares, Jorge B. [Federal University of Ceara, Fortaleza, CE (Brazil)

    2008-07-01

    Several new processes have been developed to reduce mixing and compaction temperatures of hot mix asphalt without sacrificing the quality of the resulting pavement. One of these processes utilizes the zeolite, a crystalline hydrated aluminum silicate. A laboratory study was conducted to determine the applicability of zeolite to improve the rheological and chemical behavior of an asphaltic binder. The synthetic asphaltic binder was produced with different zeolite contents (0,1; 0.3; and 0.5% w/w) by wet process. The rheological and chemical behavior was verified by Dynamic Shear Rheometer and Infrared Spectroscopy, respectively. The zeolite's chemical composition and morphology was studied by Dispersive X-ray Spectroscopy (EDX). Additionally, the scanning electron microscope (SEM) was utilized to establish the zeolite elemental composition. The results showed that investigated zeolite was classified as a sodium aluminum silicate and it was able to modify the rheological properties of the neat asphalt binder. The G*/sin{delta} parameter was affected by the zeolite presence, indicating better performance for the binders with zeolite. The results show that synthetic binders can partly replicate the rheological properties of conventional AB. Comparable complex modulus values was obtained. No significant difference was found in viscoelastic response, given by the phase angles as a function of both temperature and frequency. (author)

  3. Investigation of γ-(2,3-Epoxypropoxypropyltrimethoxy Silane Surface Modified Layered Double Hydroxides Improving UV Ageing Resistance of Asphalt

    Directory of Open Access Journals (Sweden)

    Canlin Zhang

    2017-01-01

    Full Text Available γ-(2,3-Epoxypropoxypropyltrimethoxy silane surface modified layered double hydroxides (KH560-LDHs were prepared and used to improve the ultraviolet ageing resistance of asphalt. The results of X-ray photoelectron spectrometry (XPS indicated that KH560 has been successfully grafted onto the surface of LDHs. The agglomeration of LDHs particles notably reduced after KH560 surface modification according to scanning electron microscopy (SEM, which implied that the KH560 surface modification was helpful to promote the dispersibility of LDHs in asphalt. Then, the influence of KH560-LDHs and LDHs on the physical and rheological properties of asphalt before and after UV ageing was thoroughly investigated. The storage stability test showed that the difference in softening point (ΔS of LDHs modified asphalt decreased from 0.6 °C to 0.2 °C at an LDHs content of 1% after KH560 surface modification, and the tendency became more pronounced with the increase of LDH content, indicating that KH560 surface modification could improve the stability of LDHs in asphalt. After UV ageing, the viscous modulus (G’’ of asphalt significantly reduced, and correspondingly, the elastic modulus (G’ and rutting factor (G*/sin δ rapidly increased. Moreover, the asphaltene increased and the amount of “bee-like” structures of the asphalt decreased. Compared with LDHs, KH560-LDHs obviously restrained performance deterioration of the asphalt, and helped to relieve the variation of the chemical compositions and morphology of asphalt, which suggested that the improvement of KH560-LDHs on UV ageing resistance of asphalt was superior to LDHs.

  4. Evaluation of steel slag coarse aggregate in hot mix asphalt concrete.

    Science.gov (United States)

    Ahmedzade, Perviz; Sengoz, Burak

    2009-06-15

    This paper presents the influences of the utilization of steel slag as a coarse aggregate on the properties of hot mix asphalt. Four different asphalt mixtures containing two types of asphalt cement (AC-5; AC-10) and coarse aggregate (limestone; steel slag) were used to prepare Marshall specimens and to determine optimum bitumen content. Mechanical characteristics of all mixtures were evaluated by Marshall stability, indirect tensile stiffness modulus, creep stiffness, and indirect tensile strength tests. The electrical sensitivity of the specimens were also investigated in accordance with ASTM D257-91. It was observed that steel slag used as a coarse aggregate improved the mechanical properties of asphalt mixtures. Moreover, volume resistivity values demonstrated that the electrical conductivity of steel slag mixtures were better than that of limestone mixtures.

  5. Long-term evaluation of the fate of sulfur mustard on dry and humid soils, asphalt, and concrete.

    Science.gov (United States)

    Mizrahi, Dana M; Goldvaser, Michael; Columbus, Ishay

    2011-04-15

    The long-term fate of the blister agent sulfur mustard (HD, bis(2-chloroethyl)sulfide) was determined in a variety of commercial and natural matrices. HD was found to be extremely stable in dry matrices for over a year. The addition of 5% water to the matrices induced slow degradation of HD, which lasted several months. The major degradation product in sands and asphalt was found to be a sulfonium salt, S[CH(2)CH(2)S(+)(CH(2)CH(2)OH)(2)](2) (H-2TG). Red loam soil, which has not been examined before, exhibited strong interaction with HD, both in dry form and in the presence of water. Humid red loam soil gave rise to unique oxidative degradation products. On humid concrete HD degraded to a complex mixture of products, including vinyls. This may be attributed to the basic sites incorporated in concrete.

  6. Slow dynamic diagnosis of asphalt concrete specimen to determine level of damage caused by static low temperature conditioning

    Science.gov (United States)

    Bekele, Abiy; Birgisson, Björn; Ryden, Nils; Gudmarsson, Anders

    2017-02-01

    The phenomenon of slow dynamics has been observed in a variety of materials which are considered as relatively homogeneous that exhibit nonlinearity due to the presence of defects or cracks within them. Experimental realizations in previous work suggest that slow dynamics can be in response to acoustic drives with relatively larger amplitude as well as rapid change of temperature. Slow dynamics as a nonlinear elastic response of damaged materials is manifested as a sharp drop and then recovery of resonance frequency linearly with logarithmic time. In this work, slow dynamics recovery is intended to be used as a means of identifying and evaluating thermal damage on an asphalt concrete specimen. The experimental protocol for measuring slow dynamics is based on the technique of nonlinear resonance spectroscopy and is set up with non-contact excitation using a loud speaker and the data acquisition tool box of Matlab. Sweeps of frequency with low amplitude are applied in order to probe the specimen at its linear viscoelastic state. The drop and then recovery in fundamental axially symmetric resonance frequency is observed after the specimen is exposed to sudden temperature change. The investigation of the viscoelastic contribution to the change in resonance frequency and slow dynamics can help identify micro-damage in asphalt concrete samples.

  7. Durability of styrene-butadiene latex modified concrete

    Energy Technology Data Exchange (ETDEWEB)

    Shaker, F.A.; El-Dieb, A.S.; Reda, M.M. [Ain Shams Univ., Cairo (Egypt). Dept. of Structural Engineering

    1997-05-01

    The durability of reinforced concrete structures represents a major concern to many investigators. The use of latex modified concrete (LMC) in construction has urged researchers to review and investigate its different properties. This study is part of a comprehensive investigation carried on the use of polymers in concrete. The main objective of this study to investigate and evaluate the main durability aspects of Styrene-Butadiene latex modified concrete (LMC) compared to those of conventional concrete. Also, the main microstructural characteristics of LMC were studied using a Scanning Electron Microscope (SEM). The SEM investigation of the LMC showed major differences in its microstructure compared to that of the conventional concrete. The LMC proved to be superior in its durability compared to the durability of conventional concrete especially its water tightness (measured by water penetration, absorption, and sorptivity tests), abrasion, corrosion, and sulphate resistance.

  8. Rutting analysis of 100 mm diameter polypropylene modified asphalt specimens using gyratory and Marshall compactors

    Directory of Open Access Journals (Sweden)

    Serkan Tapkın

    2013-04-01

    Full Text Available Compaction technique used in Marshall design does not model the process of actual rolling procedures on site exactly. Carrying out laboratory compaction of dense bituminous mixtures with Superpave gyratory compactors is a more realistic way of simulating actual compaction. In this study, mechanical differences of reference and polypropylene modified asphalt mixtures were compared using Superpave gyratory and Marshall compaction methods by carrying out repeated creep tests utilising universal testing machine. In addition, there is no standard Superpave design procedure for 100 mm diameter samples till date. The other purpose of this study is to propose new standards for the compaction and testing procedures of these 100 mm specimens. Indeed, extensive studies have shown that the design gyration number should be 40 for reference and 33 for polypropylene modified specimens under medium traffic conditions for the similar and specific type of aggregate sources, bitumen, aggregate gradation, mix proportioning, modification technique and laboratory conditions. Moreover, it was shown that, the asphalt samples produced by Superpave gyratory compactor were much resistant to destructive rutting effects than the asphalt specimens prepared by Marshall design.

  9. Discussion on maintenance of asphalt concrete pavement in the rural highway%论农村公路沥青混凝土路面养护方法

    Institute of Scientific and Technical Information of China (English)

    邹海洋

    2013-01-01

    Asphalt concrete pavement with many excellent properties is widely used in road construction.But the asphalt concrete pavement in the use of the process will still exist all kinds of diseases,these diseases will have a very negative impact on the road quality and traffic safety.This paper expounds the importance of rural highway maintenance,then introduces the diseases and causes of asphalt concrete pavement,at last puts forward maintenance measures of asphalt concrete pavement of rural highway.%沥青混凝土路面具备很多优良的性能,在道路建设中应用非常广泛。但是沥青混凝土路面在使用过程中,还是会存在各种各样的病害,这些病害对公路质量水平和行车安全会产生十分不利的影响。文章阐述了农村公路养护的重要性,介绍了沥青混凝土路面的病害和成因,并提出了农村公路沥青混凝土路面养护措施。

  10. The effect of cyclic hardening on fatigue properties of modified asphalt

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The phenomenon of cyclic hardening is observed in fatigue tests of modified asphalt controlled by low strain/stress level and it is not clear how the phenomenon affects the fatigue properties of binders. The special time weep tests were performed to investigate the point. Tests results indicate that the cyclic hardening is caused by the rearrangement of molecules in binders, and it can make the inner structure of binders getting stable and increase the fatigue properties of asphalt binders. But fatigue damage occurs when fatigue tests start, no matter the phenomenon of cyclic hardening happens or not. If the controlled load is low, the effect of rearrangement of molecules on material is beyond the effect of fatigue damage so that the cyclic hardening can be observed. When the load conditions get worse, the effect of slight fatigue damages produced in hardening stage will show.

  11. Assessment of dynamic modulus of high density polypropylene waste fiber reinforcement in asphalt concrete

    Directory of Open Access Journals (Sweden)

    Hassan S. OTUOZE

    2015-12-01

    Full Text Available Traditional asphalt tests like Hveem and Marshall tests are at best mere characterization than effective test of pavement field performance because of complex viscoelastic behavior of asphalt. Mechanical properties otherwise called simple performance tests (SPT are performance criteria of asphalt. Dynamic modulus among other SPT’s like permanent deformation, fatigue cracking, thermal cracking, moisture susceptibility, shear and friction properties; determines stress-strain to time-temperature relationships that imparts on strength, service life and durability. The test followed the recommendations of NCHRP 1-37a (2004 and mixes were prepared using 0, 0.5, 1.0 and 1.5% HDPP contents. The parameters tested for dynamic modulus, /E*/, are stiffness, recoverable strain (ε, and phase angle (ξ. Time – temperature superposition (TTS called master curve was fitted using sigmoidal curve to interpolate the parameters beyond measured data set so as to observe the viscoelastic behavior outside the physical properties. The performance of 0.5% HDPP asphalt is better enhanced than the conventional asphalt to improve upon strength, service and durability.

  12. Effects of Diatomite and SBS on Freeze-Thaw Resistance of Crumb Rubber Modified Asphalt Mixture

    Directory of Open Access Journals (Sweden)

    Haibin Wei

    2017-01-01

    Full Text Available Asphalt mixture is susceptible to moisture damage under the effect of freeze-thaw (F-T cycles. In this paper, crumb rubber (CR was used to modify stone mastic asphalt (SMA and the effects of diatomite and styrene butadiene styrene (SBS on antifreezing performances of crumb rubber modified SMA (CRSMA were investigated. Regression analysis and modified grey model (MGM were used to construct the prediction models for properties of modified mixtures. CRSMA, CR and diatomite modified SMA (CRDSMA, and CR and SBS modified SMA (CRSSMA were prepared in laboratory, respectively. Process of F-T cycles was designed. Air void, indirect tensile strength (ITS, and indirect tensile stiffness modulus (ITSM were measured to evaluate the antifreezing performances of CRSMA, CRDSMA, and CRSSMA. Results indicate that air voids increase with the increasing of F-T cycles. ITS and ITSM all decrease with the increasing of F-T cycles. The addition of diatomite and SBS can reduce the air void and improve the ITS and ITSM of CRSMA. CRSSMA presents the lowest air void, highest tensile strength, and largest stiffness modulus, which reveals that CRSSMA has the best F-T resistance among three different kinds of mixtures. Moreover, MGM (1, 2 models present more favorable accuracy in prediction of air void and ITS compared with regression ones.

  13. 沥青改性对粗粒式沥青混凝土的性能影响分析%Performance Impact Analysis of Asphalt Modification on Coarse Grained Type Asphalt Concrete

    Institute of Scientific and Technical Information of China (English)

    赵茜

    2012-01-01

    针对下面层沥青混合料的水稳定性和抗车辙性能进行研究,选择普通沥青、SBS改性沥青以及岩沥青改性对粗粒式沥青混合料AC25进行改性,对比其性能的优劣。研究结果表明采用岩沥青改性可以大大提高下面层沥青混合料的性能,是一种较好的提高长大纵坡以及交叉口区域沥青路面性能的方法。%Common asphalt, SBS modified asphalt and rock bitumen modification of coarse grained type AC25 modified asphalt mix- ture was chose to compare their performance. The results show that the rock asphalt modification can greatly improve the levels of asphalt mixture performance, and it is a better method to improve the performance of asphalt pavement under the long downhill and intersection area.

  14. Road Performance of High Modulus Asphalt Concrete Additive Calcium Sulfate Whisker%硫酸钙晶须高模量沥青混凝土的路用性能

    Institute of Scientific and Technical Information of China (English)

    王修山

    2011-01-01

    从路用性能出发,对3种混合料进行试验,对比研究了新型高模量无机改性剂硫酸钙晶须在沥青混合料中的应用效果.结果显示:硫酸钙晶须改性的高模量沥青混合料可以在不降低混合料低温性能的同时,有效地提高混合料的高温稳定性、水稳性和抗疲劳性能,可行性分析证明:酸钙晶须高模量沥青混凝土路用性能良好,并且有着较高的经济效益与社会效益.%The application effect of high modulus asphalt concrete additive calcium sulfate whisker in the asphalt mixtures is studied on the basis of road performance. Three mixtures are involved in the experiment and a comparative study of test results are carried out. The results show that the high modulus of asphalt mixture which is modified by calcium sulfate whisker can effectively improve the high temperature stability, water stability and anti-fatigue performance; at the same time, it doesn't decrease the mixture low temperature performance. Finally, the feasibility analysis shows that: the road performance of calcium whisker high modulus asphalt concrete pavement is good and it has high economic and social benefits.

  15. Laboratory performance of asphalt rubber mixtures

    OpenAIRE

    Fontes, Liseane; Trichês, Glicério; Pais, Jorge; Pereira, Paulo; Minhoto, Manuel

    2009-01-01

    Asphalt rubber mixtures are one of the most promising techniques to extend the service life of asphalt pavement overlays. Asphalt rubber binder is composed of crumb rubber from reclaimed tires and conventional asphalt. The asphalt rubber binder can be obtained through wet process in two different systems: tire rubber modified asphalt binder (produced at industrial plants) and continuous blending (produced in asphalt plants). This study presents a laboratory evaluation of asphalt rubber mixtur...

  16. Valorization of phosphogypsum waste as asphaltic bitumen modifier.

    Science.gov (United States)

    Cuadri, A A; Navarro, F J; García-Morales, M; Bolívar, J P

    2014-08-30

    The accumulation of phosphogypsum waste from the fertilizer industries, which remain in regulated stacks occupying considerable land resources, is causing significant environment problems worldwide. In that sense, the scientific community is being pressured to find alternative ways for their disposal. In this research, we propose a novel application for phosphogypsum waste, as a modifier of bitumen for flexible road pavements. Viscous flow tests carried out on bitumen modified with a phosphogypsum waste and doped with sulfuric acid demonstrated an extraordinary increase in viscosity, at 60°C, when compared to a counterpart sample which had been modified with gypsum, the main component of phosphogypsum. Similarly, a significant improvement in the viscoelastic response of the resulting material at high temperatures was also found. FTIR (Fourier transform infrared spectroscopy) scans provided evidences of the existence of chemical reactions involving phosphorus, as revealed by a new absorption band from 1060 to 1180cm(-1), related to COP vibrations. This result points at phosphorus contained in the phosphogypsum impurities to be the actual "modifying" substance. Furthermore, no COP band was observed in the absence of sulfuric acid, which seems to be the "promoting" agent of this type of bond.

  17. INVESTIGATING EFFECTS OF AMINE BASED MODIFIER ON RECYCLED ASPHALT SHINGLES BLENDING

    Directory of Open Access Journals (Sweden)

    Govinda Sedhay

    2014-01-01

    Full Text Available A laboratory study was conducted to investigate the effects of Amine based modifier on rheological characteristics of particle filled viscous medium such as asphalt binder in presence of Recycled Asphalt Shingles (RAS. In this study, virgin asphalt binder (PG 64-22, three different percentages (20, 30 and 40% of tear-off shingles and modifiers; Rediset, Evotherm and Bio-binder were used. The tear-off shingles acquired from local reroofing company in Greensboro, North Carolina; were finely grinded (85% passing of sieve # 200. The virgin binder and different percentages of RAS were then blended at 180°C using shearing speed of 400 rpm. Following that themixture was blended with 1.5% of Rediset, 0.5% of Evotherm and 5% of bio-binder. The properties of the blended binder were studied using the Rotational Viscometer (RV equipped with two different spindle types:- One was Smooth Cylindrical spindle (SC4-27D and the other one was Vane spindle (V 73. The analysis showed that the viscosity was increased with increasing the RAS percentage. Furthermore, the viscosity measured by vane spindle was continuously higher than the value measured by smooth spindle; however the difference between the two measurements reduced as the blending were improved using modifiers. Moreover, temperature found to be the main contributor to reduction of the viscosity in both spindles cases. In addition the coefficient of variation was significantly lower in the case of vane spindle, indicating that the vane spindle could be more appropriate in measuring viscosity of particle filled viscous medium such as RAS asphalt. Based on the experimental result an empirical index called blending index was introduced in this study to measure the blending behavior and status for modified mixtures. As expected it was found that the blending index increases as the temperature and rotational speed increases. In other word, higher temperature and shearing rate could enhance blending resulting

  18. Deformation behavior and load limits of asphaltic concrete under the conditions of cores in embankment dams; Deformationsverhalten und Belastungsgrenzen des Asphaltbetons unter den Bedingungen von Staudammkerndichtungen

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, U.

    1998-12-31

    Based on the analysis of existing dams with asphaltic diaphragm and investigations in the three-phase-system of asphaltic concrete a recipe for the composition of asphaltic cores is recommended. For the construction, rest and operating period of an embankment dam the load and the reaction of the asphaltic concrete cores as well as the appearing stress and deformations are described. Extensive material testings have been performed and at 41 asphaltic concrete specimens triaxial stress controlled pressure and creeping tests have been carried out. The evaluation of the triaxial tests led to proportions of the main stress and deformation limits as criteria of breaking. Under application of the standard equation for nonlinear viscoelastic element-laws a rheonom element formulation was developed from the experiment data and transformed into its differential form. With this approach the stress and deformation behavior of watertight asphaltic diaphragm can be precalculated for a period up to 10 years. The applicability of this approach, which can be also used within FE-calculations as well, is illustrated in four examples. (orig.) [Deutsch] Nach der Analyse bestehender Staudaemme mit Asphaltbetonkerndichtung und Untersuchungen zum Dreiphasensystem Asphaltbeton wird eine Rezepturempfehlung fuer den Asphaltkerndichtungsbau aufgestellt. Fuer die Bau-, Ruhe- und Betriebsphase eines Staudammes werden die Beanspruchungen und Reaktionen der Asphaltbetonkerndichtung sowie die auftretenden Spannungen und Verformungen beschrieben. Nach umfangreichen Materialpruefungen sind an 41 Asphaltbetonpruefkoerpern triaxiale spannungsgesteuerte Druck-Kriechversuche durchgefuehrt worden. Die Auswertung der Triaxialversuche ergab ein Grenzhauptspannungsverhaeltnis und Deformationsgrenzen als Bruchkriterien. Unter Verwendung der Standarformulierung fuer nichtlineare viskoelastische Stoffgesetze wurde aus den Versuchsdaten ein rheonomer Stoffansatz entwickelt und in seine differentielle Form

  19. On the combined effect of moisture diffusion and cyclic pore pressure generation in asphalt concrete

    NARCIS (Netherlands)

    Varveri, A.; Scarpas, A.; Collop, A.; Erkens, S.M.J.G.

    2014-01-01

    In this paper, a new moisture conditioning protocol which attempts to distinguish the contributions of long- and short-term moisture damage, i.e. moisture diffusion and cyclic pore pressure generation, in asphalt mixtures is presented. The capability of the proposed protocol to rank various aspha

  20. Photoactive roadways: Determination of CO, NO and VOC uptake coefficients and photolabile side product yields on TiO2 treated asphalt and concrete

    Science.gov (United States)

    Toro, C.; Jobson, B. T.; Haselbach, L.; Shen, S.; Chung, S. H.

    2016-08-01

    This work reports uptake coefficients and by-product yields of ozone precursors onto two photocatalytic paving materials (asphalt and concrete) treated with a commercial TiO2 surface application product. The experimental approach used a continuously stirred tank reactor (CSTR) and allowed for testing large samples with the same surface morphology encountered with real urban surfaces. The measured uptake coefficient (γgeo) and surface resistances are useful for parametrizing dry deposition velocities in air quality model evaluation of the impact of photoactive surfaces on urban air chemistry. At 46% relative humidity, the surface resistance to NO uptake was ∼1 s cm-1 for concrete and ∼2 s cm-1 for a freshly coated older roadway asphalt sample. HONO and NO2 were detected as side products from NO uptake to asphalt, with NO2 molar yields on the order of 20% and HONO molar yields ranging between 14 and 33%. For concrete samples, the NO2 molar yields increased with the increase of water vapor, ranging from 1% to 35% and HONO was not detected as a by-product. Uptake of monoaromatic VOCs to the asphalt sample set displayed a dependence on the compound vapor pressure, and was influenced by competitive adsorption from less volatile VOCs. Formaldehyde and acetaldehyde were detected as byproducts, with molar yields ranging from 5 to 32%.

  1. Discussion on paving construction technology of asphalt concrete core wall:with construction of Ethiopia asphalt concrete core wall as an example%沥青混凝土心墙铺筑施工技术探讨--以埃塞沥青混凝土心墙施工为例

    Institute of Scientific and Technical Information of China (English)

    谢盛

    2015-01-01

    本文结合 Wolkite 沥青混凝土心墙项目,全程系统地探讨了沥青混凝土心墙施工技术,意在为同类型情况下心墙施工提供参考实例。%Wolkite asphalt concrete core wall project is combined for systematically discussing the construction technology of asphalt concrete core wall in the whole process.Reference example is provided for core wall construction under the same type conditions.

  2. Investigation of Self Consolidating Concrete Containing High Volume of Supplementary Cementitious Materials and Recycled Asphalt Pavement Aggregates

    Science.gov (United States)

    Patibandla, Varun chowdary

    The use of sustainable technologies such as supplementary cementitiuous materials (SCMs), and/or recycled materials is expected to positively affect the performance of concrete mixtures. However, it is important to study and qualify such mixtures and check if the required specifications of their intended application are met before they can be implemented in practice. This study presents the results of a laboratory investigation of Self Consolidating concrete (SCC) containing sustainable technologies. A total of twelve concrete mixtures were prepared with various combinations of fly ash, slag, and recycled asphalt pavement (RAP). The mixtures were divided into three groups with constant water to cementitiuous materials ratio of 0.37, and based on the RAP content; 0, 25, and 50% of coarse aggregate replaced by RAP. All mixtures were prepared to achieve a target slump flow equal to or higher than 500 mm (24in). A control mixture for each group was prepared with 100% Portland cement whereas all other mixtures were designed to have up to 70% of portland cement replaced by a combination of supplementary cementitiuous materials (SCMs) such as class C fly ash and granulated blast furnace slag. The properties of fresh concrete investigated in this study include flowability, deformability; filling capacity, and resistance to segregation. In addition, the compressive strength at 3, 14, and 28 days, the tensile strength, and the unrestrained shrinkage up to 80 days was also investigated. As expected the inclusion of the sustainable technologies affected both fresh and hardened concrete properties. Analysis of the experimental data indicated that inclusion of RAP not only reduces the ultimate strength, but it also affected the compressive strength development rate. Moreover, several mixes satisfied compressive strength requirements for pavements and bridges; those mixes included relatively high percentages of SCMs and RAP. Based on the results obtained in this study, it is not

  3. Evaluation of the use of polymer modified bitumen in the production of high modulus asphalt for heavily-trafficked roads

    CSIR Research Space (South Africa)

    Komba, Julius J

    2015-05-01

    Full Text Available South African asphalt producer, introduced the use of Ethylene Vinyl Acetate (EVA) polymer-modified bitumen for the production of HiMA. The modified bitumen was used to produce two types of HiMA mixes; one for a base course and one for the wearing course...

  4. Evaluation of the corrosion resistance of latex modified concrete (LMC)

    Energy Technology Data Exchange (ETDEWEB)

    Okba, S.H.; El-Dieb, A.S.; Reda, M.M. [Ain Shams Univ., Cairo (Egypt). Dept. of Structural Engineering

    1997-06-01

    In recent years, various reinforced concrete structures worldwide have suffered rapid deterioration. Therefore, durability of concrete structures especially those exposed to aggressive environments is of great concern. Many deterioration causes and factors have been investigated. Corrosion of steel reinforcement was found to be one of the major deterioration problems. Penetration of chloride ions is one of the main causes which induces corrosion. The objective of this study is to evaluate the corrosion resistance of latex modified concrete (LMC) compared to conventional concrete using an accelerated corrosion cell. The corrosion cell proved to be a good and simple method to evaluate the durability of concretes especially with respect to chloride ion penetration, and the protection of reinforcement against corrosion. The LMC proved to be superior in its corrosion resistance compared to conventional concrete, which recommends its use in structures exposed to severe aggressive environments.

  5. Investigation of Using Waste Welded Tuff Material as Mineral Filler in Asphalt Concrete

    Directory of Open Access Journals (Sweden)

    Sebnem KARAHANCER

    2016-08-01

    Full Text Available In this paper, the welded tuff waste- known as koyke in Isparta region - was used in the hot mix asphalt (HMA as mineral filler for reduction of the moisture susceptibility of HMA. Optimum binder content was assessed with Marshall Design Method. First of all, welded tuff was substituted as filler with limestone filler in proportion of 50% and 100%. After that Marshall Stability test was performed on specimens. The results showed that the 50% substitution was more effective than the 100% substitution. Therefore, welded tuff was substituted with limestone filler in proportion of 25%, 50%, 65% and 75%. Next, Indirect Tensile Strength test was practiced on the fabricated specimens and the results were assessed. According to the Indirect Tensile Strength results, welded tuff with 65% was given higher strength than the limestone filler. As a result, it has come up that welded tuff can be used as mineral filler in the hot mix asphalt.

  6. 沥青混凝土面层碎石集料的质量控制%Quality control of gravel aggregate of asphalt concrete surface layer

    Institute of Scientific and Technical Information of China (English)

    高明成

    2011-01-01

    From the gravel aggregate production and processing,transportation,storage and other aspects,this paper provided points of requirements of asphalt,the upper layer of gravel aggregate quality control,maximum reduced the influence of raw material to the construction quality and durability of asphalt concrete pavement,and improved the service performance of asphalt pavement.%从碎石集料生产加工、运输、存放等方面,提出沥青中、上面层碎石集料质量控制的几点要求,最大限度的减小原材料对沥青混凝土面层施工质量及耐久性的影响,进而提高沥青路面使用性能。

  7. Preparation of capsules containing rejuvenators for their use in asphalt concrete.

    Science.gov (United States)

    García, Alvaro; Schlangen, Erik; van de Ven, Martin; Sierra-Beltrán, Guadalupe

    2010-12-15

    Every year, there is a demand of more than 110 million metric tons of asphalt all around the world. This represents a huge amount of money and energy, from which a good part is for the preservation and renovation of the existing pavements. The problem of asphalt is that it oxidizes with time and therefore its beneficial properties disappear. Traditionally, rejuvenators spread in the road surface, are used to restore the original properties of the pavement. The problem is that, for a rejuvenator to be successful, it must penetrate the pavement surface. Furthermore, application of a rejuvenator will reduce the skid resistance of the pavement and, besides, rejuvenators have many aromatic compounds that can be harmful for the environment. To solve these problems this paper introduces a new concept in road construction: encapsulated rejuvenators. The basic principle is that when the stress in capsules embedded in the asphalt reaches a certain threshold value, the capsules break and some rejuvenator is released, restoring the original properties of the pavement. This paper will show how to prepare such capsules and how to determine their characteristics. This is one of the first steps towards intelligent pavements.

  8. Modelling Effect of Aggregate Gradation and Bitumen Content on Marshall Properties of Asphalt Concrete

    Directory of Open Access Journals (Sweden)

    Arief Setiawan

    2017-04-01

    Full Text Available Current selection of aggregate gradation fails to explain completely the position of the aggregate gradation on a continuous scale. This study proposes a gradation index (GI as a new parameter to determine the position ofthe aggregate gradation of the asphalt mixture on the continuous scale. The GI was used to develop a model of the Marshall properties. The aim of this study was todevelopa model between the GI and  bitumen content of the Marshall properties that includes density, voids in the mix (VIM, voids in mineral aggregate (VMA, voids filled with asphalt (VFA, stability, and flow. The materials used were unmodified Asphalt Cement 60/70 with bitumen content variation of 4.5% to 8.0% of the mix and five variations of the aggregate gradation. Curve fitting method is used to find partial correlation factor of the aggregate gradation and the bitumen content of the Marshall properties. Multiple Polynomial Regression (MPR models were specified to find the relationship between the GI and bitumen content of the Marshall properties. The visualization of the relationship between the GI, bitumen content and Marshall properties used contour charts. The results showed that the MPR determines the model of the relationship between theGI and bitumen content of the density, VIM, VMA, VFA, stability, and flow that have a very strong relationship (R2 > 0.9.Therefore, the model can be used to predict the Marshall properties.

  9. 2D and 3D Ground Penetrating Radar monitoring of a reinforced concrete asphalt plate affected by mechanical deformation.

    Science.gov (United States)

    Bavusi, M.; Dumoulin, J.; Loperte, A.; Rizzo, E.; Soldovieri, F.

    2012-04-01

    The main facility of Hydrogeosite Laboratory of the Italian National Research Council (Marsico Nuovo, CNR) is a 3m x 7m x 10m reinforced concrete pool filled by siliceous sand designed for hydrologic experiments. One of its peculiarities is the possibility to vary the water table depth by using a proper hydraulic system [1]. In the framework of the FP7 ISTIMES project (Integrated System for Transport Infrastructure surveillance and Monitoring by Electromagnetic Sensing), a 3m x 3m layered structure has been purposely built and placed in the pool of the Hydrogeosite Laboratory with the aim to carry out a long term monitoring, by using jointly several electromagnetic sensing technologies, during two different phases simulating the rising of the water table and a mechanical solicitation. Several layers composed the structure from the top to the bottom, such as: 5 cm of asphalt; 5-10 cm of reinforced concrete; 20-25 cm of conglomerate, 55 cm of sand. Moreover, in the sand layer, three (metallic and plastic) pipes of different size were buried to simulate utilities. Ground Penetrating Radar (GPR) surveys were performed by using a the GSSI SIR 3000 system equipped with 400 MHz and 1500 MHz central frequency antennas. Surveys carried out by means of 400 MHz antenna allowed to detect and localize the three pipes (one in plastic and two in metal) and to investigate the effects of the sand water content on their radar signature. Surveys carried out by using 1500 MHz antenna were focused to characterize the shallower layers of the structure. The Hydrogeosite experiment consisted in following stages: • Arising of a water table by infiltration from the bottom; • Water gravity infiltration condescendingly; • Infiltration by peristaltic pump in the very shallow layers of the structure; • Water table drawdown; • Mechanical structure deformation; • Asphalt plate restoration after mechanical solicitation. After each stage a series of GPR surveys was performed. Moreover

  10. Uniaxial impact compressive characteristics of permeable asphalt concrete%透水沥青混凝土单轴冲击压缩特性研究

    Institute of Scientific and Technical Information of China (English)

    吴金荣; 马芹永

    2015-01-01

    In order to investigate the dynamic characteristics of permeable asphalt concrete,a 74mm steel split Hopkinson pressure bar (SHPB)apparatus was used to conduct uniaxial impact compressive test with various strain rates for permeable asphalt concretes with polyester fiber content of 0 and 0.3%.The test results showed that there is a significant strain rate effect on permeable asphalt concrete and the specimen compression ratio increases with increase in strain rate;the specimen compression ratio of the permeable asphalt concrete with polyester fiber is about 1.2 times as large as that of the concrete without polyester fiber;the dynamic stress-strain curve of permeable asphalt concrete includes 3 stages of elastic deformation stage,plastic deformation one and failure one;observing the failure mode of permeable asphalt concrete,the aggregate fracture is considered as the main reason for permeable asphalt concrete failure;polyester fiber in permeable asphalt concrete can delay cracks appearing and spreading and improve dynamic compressive strength, the largest strength increase can reach 45.1%.%为研究透水沥青混凝土的动态力学特性,采用φ74 mm钢质分离式霍普金森压杆装置对不掺纤维和掺0.3%聚酯纤维的透水沥青混凝土进行了不同应变率的单轴冲击压缩试验。研究表明,透水沥青混凝土具有明显的应变率效应,试件压缩率随着应变率的增大而提高,掺聚酯纤维透水沥青混凝土的压缩率是不掺纤维的1.2倍左右;透水沥青混凝土的动态应力-应变曲线可分为弹性变形阶段、塑性变形阶段和破坏阶段。从试件的破坏形态可以看出,集料的断裂是透水沥青混凝土破坏的主要原因。在透水沥青混凝土中掺加聚酯纤维能够延缓裂缝的出现和开展,提高材料的冲击抗压强度,增幅最大为45.1%。

  11. The Control of Key Processes of 2000 Type Asphaltic Concrete Mixer%2000型沥青混凝土拌和机关键工序的控制

    Institute of Scientific and Technical Information of China (English)

    王磊

    2014-01-01

    The quality of asphalt mixtures has direct influence on the quality of asphalt concrete pavement. This paper analyzes the structure and working principles of 2000 type asphaltic concrete mixer, and probes into the control measures for its main components and key processes in the production of asphalt mixtures cor exercising strict control of the quality of asphalt mixtures.%沥青混合料质量的好坏直接影响沥青混凝土路面的质量。分析了2000型沥青混凝土拌和机的结构与工作原理,探讨了在生产沥青混合料的过程中各主要部件和关键工序的控制措施,以达到沥青混合料质量的严格控制。

  12. Experimental Analysis on Rheological Properties of Modified Asphalt in Desert Area%荒漠地区改性沥青流变性能试验分析

    Institute of Scientific and Technical Information of China (English)

    沈宁; 杨三强

    2016-01-01

    为了研究荒漠地区两种常用沥青流变性能,采用DSR、BBR的试验方法分别对RTFOT短期老化前后沥青的流变参数进行对比分析,得出短期老化前后沥青性能排序。结果表明:高温下RTFOT前后沥青流变性能顺序为橡胶改性沥青>SBS改性沥青;低温下沥青RTFOT前流变性能顺序为SBS改性沥青>橡胶改性沥青,而沥青RTFOT后低温流变性能顺序为橡胶改性沥青>SBS改性沥青。研究表明在荒漠地区橡胶改性沥青的流变性能优于SBS改性沥青,短期老化提升了沥青抵抗流动变形的能力。%In order to study the theological properties of two kinds of asphalt used in desert area, the DSR and BBR test methods are used to compare and analyze the rheological parameters of asphalt before and after the short-term aging of RTFOT and obtain the asphalt performance sort before and after the short-term aging. Results show that, under high temperature, the asphalt rheological properties order before and after RTFOT is rubber modified asphalt> SBS modified asphalt, under low temperature, the asphalt rheological properties order before and after RTFOT is SBS modified asphalt> rubber modified asphalt, the rheological property order of asphalt at low temperature after RTFOT is rubber modified asphalt>SBS modified asphalt. Research shows that rheological property of rubber modified asphalt is better than that of SBS modified asphalt in desert region, and short-term aging improves the ability of asphalt to resist flow deformation.

  13. 纳米改性沥青混合料路用性能%Pavement performance of nanomaterial modified asphalt mixture

    Institute of Scientific and Technical Information of China (English)

    孙璐; 辛宪涛; 任皎龙

    2013-01-01

    The high temperature stability,the low temperature crack resistance and the water stability of nano-SiO2 modified asphalt mixture,bentonite modified asphalt mixture,nano-SiO2/bentonite complex modified asphalt mixture and nano-SiO2/bentonite/SBS complex modified asphalt mixture are studied by laboratory experiments in comparison with matrix asphalt mixture and SBS modified asphalt.The results show that compared with matrix asphalt mixture,the high temperature stability and the water stability of nano-SiO2 modified asphalt mixture,bentonite modified asphalt mixture and nano-SiO2/bentonite complex modified asphalt mixture increase 56% to 77% and 3% to 7%,respectively,while there are no obvious differences when compared with SBS modified asphalt mixture.The high temperature stability and the water stability of nano-SiO2/bentonite/SBS complex modified asphalt mixture are the highest in the six kinds of asphalt,and they are 86% and 3% higher than those of SBS modified asphalt mixture respectively.The low temperature performance of nanoSiO2 modified asphalt mixture,bentonite modified asphalt mixture and nano-SiO2/bentonite complex modified asphalt mixture decreases slightly,but it still satisfies the requirement of the low temperature crack resistance on asphalt pavement.Therefore,the nanomaterial modified asphalt mixture has excellent pavement performance and it is suitable for the application of asphalt modified technology.%通过室内试验研究了纳米SiO2改性沥青混合料、膨润土改性沥青混合料、纳米SiO2/膨润土复合改性沥青混合料、纳米SiO2/膨润土/SBS复合改性沥青混合料的高温稳定性、低温抗裂性和水稳定性,并与基质沥青混合料和SBS改性沥青混合料进行对比.结果表明,纳米SiO2改性沥青混合料、膨润土改性沥青混合料、纳米SiO2/膨润土复合改性沥青混合料的高温稳定性较基质沥青提高了56% ~77%,水稳定性提高了3% ~7%,与SBS改

  14. Characterization of hot-mix asphalt concrete containing municipal solid waste incinerator ash using the dynamic modulus (E) test

    Energy Technology Data Exchange (ETDEWEB)

    Hassan, H.F. [Sultan Qaboos Univ., Muscat (Oman). College of Engineering

    2007-07-01

    In 2001, approximately 229 million tons of municipal solid waste (MSW) were produced in the United States. MSW consists of items such as paper, grass clippings, furniture, clothing, bottles, food scraps, appliances, paint, and batteries. MSW incinerator ash is the by-product produced during the combustion of municipal solid waste in combustor facilities and has two components, namely bottom ash and fly ash. To reduce the disposal problem, the incinerators are used to reduce the volume and weight of MSW. This is usually a self-sustained process using the waste as a fuel resulting in as much as a 90 and 75 per cent reduction in volume and weight, respectively. This paper presented the results of a study that investigated the use of incinerator ash as a partial replacement of fine aggregate in hot-mix asphalt concrete. MSW incinerator ash was collected from an incinerator facility at Sultan Qaboos University in Oman and a physical and chemical characterization of the ash was conducted. MSW ash was used in the mixture to replace fine aggregate with a percentage ranging from 0 to 40 per cent, by total aggregate weight. The mixes were designed using the Marshall mix design method and the dynamic modulus test was conducted on samples prepared at optimum asphalt contents for mixes containing different percentage of ash and at different temperatures and frequencies. Master curves for different percentages of ash in the mix were developed from the testing results. It was found that the Marshall mix design results for the mixes containing MSW ash indicated a decrease in stability, and specific gravity, and an increase in air voids. 18 refs., 10 figs.

  15. 高性能沥青混凝土机场道面结构%Airfield pavement with high performance asphalt concrete

    Institute of Scientific and Technical Information of China (English)

    钱振东; 孟凡奇; 曾靖

    2015-01-01

    To improve the anti-rutting performance of airfield pavement, a high performance airfield pavement based on a new type of epoxy asphalt concrete was proposed.With the new type of epoxy asphalt concrete EAC20 as the middle surface course, SMA13 asphalt concrete as the first surface course, and AC20 asphalt concrete as the base surface course, the SEA airfield pavement was built up.The mechanical responses of the SEA airfield pavement under the static loads of the aircraft A380 were analyzed.The permanent deformation tests of the asphalt concrete in different airfield pavement layers were carried out.The creep parameters of the asphalt concrete in each layer were obtained by using the multiple linear regression method to simulate the permanent deformation of the SEA airfield pavement.The results demonstrate that taking the new type of epoxy asphalt concrete as the middle surface course can reduce the strain of the airfield pavement.The maximum tensile strain and the maximum compressive strain on the bottom of the asphalt surface course are respectively about 68%and 72%those of the traditional airfield pavement.Under 1 ×105 loads, the permanent deformation of the SEA airfield pavement is only 6 mm, which is about 42.9%that of the traditional SAA airfield pavement.%为增强机场沥青道面的抗轮辙性能,提出了一种基于新型环氧沥青混凝土的高性能机场道面结构.将新型环氧沥青混凝土EAC20作为机场道面的中面层,SMA13型沥青混凝土作为上面层,AC20型沥青混凝土作为下面层,由此构成SEA机场道面结构.分析了新一代大型客机A380荷载作用下SEA机场道面结构的力学响应,针对机场道面各层沥青混凝土进行永久变形试验,并采用多元线性回归得到各层材料的蠕变参数,以模拟SEA机场道面结构的永久变形.研究结果表明,将新型环氧沥青混凝土作为中面层应用于机场道面,可以减小机场道面结构的应变,沥

  16. 有关改性沥青混泥土面层施工技术的探讨%Construction Technology of Surface Layer of the Modified Asphalt and Earth Mixture

    Institute of Scientific and Technical Information of China (English)

    曾靖超

    2014-01-01

    The asphalt pavement has good mechanical stren- gth, on which the mechanized construction is very convenient. So at present, the asphalt pavement has become the major pavement structure in high-type highways. However, in actual construction, the requirements of construction technology of modified asphalt are very high. Thus, it is very important to strengthen the research of the construction technology of mo- dified asphalt concrete.%沥青路面具有良好的力学强度,在采用机械化施工时也非常方便。所以在现阶段的高等级公路中,沥青路面成为了主要的路面结构。但在实际施工中,改性沥青的施工技术要求非常高,所以对加强改性沥青混泥土施工技术的研究具有非常重要的意义。

  17. Investigation on Tensile Strength Ratio (TSR Specimen to Predict Moisture Sensitivity of Asphalt Pavements Mixture and Using Polymer to Reduce Moisture Damage

    Directory of Open Access Journals (Sweden)

    Mohammed Aziz Hameed Al-Shaybani

    2017-05-01

    Full Text Available Moisture damage of asphalt concrete is defined as losing the strength and Permanence caused by the active presence of moisture.The most common technique to reduce moisture damage is using modifiers with the asphalt binder or the aggregate.The goal of this study was to explore the effect of various modifiers of polymer on the moisture susceptibility mixture of asphaltic concrete pavement. Modifiers included in this research selected two kinds of polymers Crumb Rubber No 50 (CR No 50 and Methyl Methacrylates (MMA(which are available in the local markets in Iraq and have been used in three percentages for each type. These percentages are (5, 10 and 15% for (CR No 50 and (2.5, 5 and 7.5(% for (MMA.Each type of these polymers is blended with asphalt by wet process at constant blending times for a suitable range of temperatures. The experimental works showed that all polymers modified mixtures have indirect tensile strength higher than control asphalt mixtures, its about (2-15 %, dependent on different type of polymer and polymer concentration under predicted suitable blending time.Test results of indirect tensile strength indicated betterment in modifying the proprieties of mixture, the increased resistance mixture of asphalt concrete pavement versus moisture damage, and reduced the effect of water on asphalt concrete properties. The final result is the addition of (10% CR No 50 and (5% MMA to asphalt mixtures showed an improved mixture of asphalt concrete properties and produced strong mixtures for road construction.One model is predicted for tensile strength ratio [TSR]to estimate the effects of polymer modification on moisture susceptibility mixture of asphalt concrete.

  18. Development Status and Prospect of Modified Asphalt%改性沥青的开发现状与发展前景

    Institute of Scientific and Technical Information of China (English)

    莫菊先

    2012-01-01

    The development course and research status of modified asphalt were introduced. The development prospect of modified asphalt was analyzed in aspects of development of new type modifier and improvement of general standard of asphalt mixture.%介绍了改性沥青的发展历程,阐述了改性沥青的研究现状,从发展新型的改性剂、提高沥青混合料的整体水平等方面,对改性沥青的发展前景进行了分析。

  19. Bitumen modifiers for reduced temperature asphalts: a comparative analysis between three polymeric and non-polymeric additives

    OpenAIRE

    Cuadri Vega, Antonio Abad; Carrera Páez, Virginia; Izquierdo Rodríguez, María Angeles; García Morales, Moisés; Navarro Domínguez, Francisco Javier

    2014-01-01

    This study presents three bitumen modifiers which may find successful application in the fabrication of binders for warm mix asphalt in the paving industry. In that sense, two non-polymeric additives, thiourea and thiourea dioxide, along with a reactive isocyanate-terminated prepolymer have been evaluated. Viscous flow and linear viscoelasticity tests, at 60 ºC, reveal bituminous modified binders which evolve towards highly viscous materials when subjected to ambient curing. However, at 135 º...

  20. Bitumen modifiers for reduced temperature asphalts: a comparative analysis between three polymeric and non-polymeric additives

    OpenAIRE

    Cuadri Vega, Antonio Abad; Carrera Páez, Virginia; Izquierdo Rodríguez, María Angeles; García Morales, Moisés; Navarro Domínguez, Francisco Javier

    2014-01-01

    This study presents three bitumen modifiers which may find successful application in the fabrication of binders for warm mix asphalt in the paving industry. In that sense, two non-polymeric additives, thiourea and thiourea dioxide, along with a reactive isocyanate-terminated prepolymer have been evaluated. Viscous flow and linear viscoelasticity tests, at 60 ºC, reveal bituminous modified binders which evolve towards highly viscous materials when subjected to ambient curing. However, at 135 º...

  1. Quality and seasonal variation of rainwater harvested from concrete, asphalt, ceramic tile and green roofs in Chongqing, China.

    Science.gov (United States)

    Zhang, Qianqian; Wang, Xiaoke; Hou, Peiqiang; Wan, Wuxing; Li, Ruida; Ren, Yufen; Ouyang, Zhiyun

    2014-01-01

    There is an urgent requirement to examine the quality of harvested rainwater for potable and non-potable purposes, based on the type of roofing material. In this study, we examined the effect on the quality of harvested rainwater of conventional roofing materials (concrete, asphalt and ceramic tile roofs) compared with alternative roofing materials (green roof). The results showed that the ceramic tile roof was the most suitable for rainwater-harvesting applications because of the lower concentrations of leachable pollutants. However, in this study, the green roof was not suitable for rainwater harvesting applications. In addition, seasonal trends in water quality parameters showed that pollutants in roof runoff in summer and autumn were lower than those in winter and spring. This study revealed that the quality of harvested rainwater was significantly affected by the roofing material; therefore, local government and urban planners should develop stricter testing programs and produce more weathering resistant roofing materials to allow the harvesting of rainwater for domestic and public uses.

  2. Construction Techniques of Asphalt Concrete Pavement%浅析沥青混凝土路面施工技术

    Institute of Scientific and Technical Information of China (English)

    席晓彬

    2012-01-01

    随着我国公路建设事业的发展,沥青混凝土路面由于具有表面平整、行车舒适、耐磨、噪音小、施工周期短、养护维修简便等优点,无扬尘、无振动,还具有良好的抗滑性,因而被越来越多地应用到公路建设中。因此,只有对施工组织设计以及每道工序严格地控制,才能保证沥青混凝土路面的质量。%With the development of highway construction in China,asphalt concrete pavement is widely used for its advantages of smooth surface,comfortable driving,abrasion resistance,low noise,short construction period and easy maintenance and repair,and its non-dust and non-vibration construction with better slip resistance.Therefore,every procedure in construction and design should be strictly controlled to guarantee the quality of the pavement.

  3. Environmental impact of highway construction and repair materials on surface and ground waters. Case study: crumb rubber asphalt concrete.

    Science.gov (United States)

    Azizian, Mohammad F; Nelson, Peter O; Thayumanavan, Pugazhendhi; Williamson, Kenneth J

    2003-01-01

    The practice of incorporating certain waste products into highway construction and repair materials (CRMs) has become more popular. These practices have prompted the National Academy of Science, National Cooperative Highway Research Program (NCHRP) to research the possible impacts of these CRMs on the quality of surface and ground waters. State department of transportations (DOTs) are currently experimenting with use of ground tire rubber ( crumb rubber) in bituminous construction and as a crack sealer. Crumb rubber asphalt concrete (CR-AC) leachates contain a mixture of organic and metallic contaminants. Benzothiazole and 2(3H)-benzothiazolone (organic compounds used in tire rubber manufacturing) and the metals mercury and aluminum were leached in potentially harmful concentrations (exceeding toxic concentrations for aquatic toxicity tests). CR-AC leachate exhibited moderate to high toxicity for algae ( Selenastrum capriconutum) and moderate toxicity for water fleas ( Daphnia magna). Benzothiazole was readily removed from CR-AC leachate by the environmental processes of soil sorption, volatilization, and biodegradation. Metals, which do not volatilize or photochemically or biologically degrade, were removed from the leachate by soil sorption. Contaminants from CR-AC leachates are thus degraded or retarded in their transport through nearby soils and ground waters.

  4. Mutagenicity of bitumen and asphalt fumes.

    Science.gov (United States)

    Heikkilä, P R; Väänänen, V; Hämeilä, M; Linnainmaa, K

    2003-08-01

    The mutagenicity of asphalt fumes was tested with the Salmonella bioassays. The aim was to investigate if recycled additives modify the genotoxicity of emissions. Recycling of old asphalt is increasing, and we studied also the mutagenicity of emissions sampled during the re-use of asphalt. The composition of vapours and fumes were analysed by gas chromatography and by liquid chromatography. Bitumens containing coal fly ash (CFA) or waste plastics were heated to the paving temperatures in the laboratory. In the field, bitumen fumes were collected during paving of stone mastic asphalts (lime or CFA as a filler), remixing of stone mastic asphalt (lime or CFA as a filler), and of asphalt concrete. All the lab-generated vapour fractions were non-mutagenic. The particulate fractions were mutagenic with TA98 in the presence of the S9 activation. In addition, the lab-fumes from bitumen containing waste plastics were positive with both strains without S9. Only particulate fractions sampled in the field were tested. They were mutagenic with and without metabolic activation with both strains. The mutagenic potency of the field samples was higher than that of the lab-generated fumes without S9, and the remixing fumes were more mutagenic than the normal paving and lab-generated fumes with S9. The use of inorganic additive, CFA, did not change the mutagenicity of the fumes, whereas the organic additive, waste plastics, increased the mutagenicity of the laboratory emissions significantly.

  5. Multifractal Characteristics of Asphalt Concrete Pavement Macrotexture%沥青混凝土路面宏观纹理的多重分形特征

    Institute of Scientific and Technical Information of China (English)

    苗英豪; 宋萍萍

    2013-01-01

    为深入分析沥青混凝土路面表面宏观纹理特征,在12条不同等级的道路上,选取了包含沥青混凝土(AC)、沥青玛蹄脂碎石(SMA)、开级配抗滑磨耗层(OGFC)、微表处(MS)和稀浆封层(SS)等路面类型的35个测试点,利用激光断面仪开展了路面表面宏观纹理断面的现场测试.分析表明,沥青混凝土路面表面宏观纹理断面具有典型的多重分形特征,多重分形谱呈向右的钩形,多重分形谱的分布宽度(△a)反映了路面断面起伏幅度的变化范围,与路面表面平均断面深度(MPD)之间有较为显著的相关性.最小概率子集与最大概率子集的分形维数差(△f(a))表征了路面表面纹理不同起伏幅度的分布情况,从一个新的角度描述了路面表面断面的特征,丰富了对路面表面宏观纹理特征的描述.%To deeply understand the features of asphalt concrete pavement macrotexture, field tests are conducted using laser profile tester at 35 test sites in 12 sections with 5 pavement types including Asphalt Concrete (AC), Stone Matrix Asphalt (SMA), Open Graded Friction Course (OGFC), Micro-Surfacing (MS) , and Slurry Seal (SS). It is shown that profile of asphalt concrete pavement macrotexture has significant multifractal property. All multifractal spectrums are like a hook facing right. The width of multifractal spectrum (△a) indicates the variation range of profile amplitude, which has significant correlation-ship with the Mean Profile Depth (MPD). Fractal dimension difference between the subset with minimum probability and the subset with maximum probability (△f(a)) describes the distribution of profile amplitude which characterizes the pavement macrotexture from another view and is a new choice for asphalt concrete pavement macrotexture charecterization.

  6. Influence of Compaction Temperature on Resistance Under Monotonic Loading of Crumb-Rubber Modified Hot-Mix Asphalts

    Directory of Open Access Journals (Sweden)

    Hugo A. Rondón-Quintana

    2012-12-01

    Full Text Available The influence of compaction temperature on resistance under monotonic loading (Marshall of Crumb-Rubber Modified (CRM Hot-Mix Asphalt (HMA was evaluated. The emphasis of this study was the application in Bogotá D.C. (Colombia. In this city the compaction temperature of HMA mixtures decreases, compared to the optimum, in about 30°C. Two asphalt cements (AC 60-70 and AC 80-100 were modified. Two particle sizes distribution curve were used. The compaction temperatures used were 120, 130, 140 and 150°C. The decrease of the compaction temperature produces a small decrease in resistance under monotonic loading of the modified mixtures tested. Mixtures without CRM undergo a lineal decrease in its resistance of up to 34%.

  7. Discussion on crack problems of asphalt concrete pavement%沥青混凝土路面裂缝问题的探讨

    Institute of Scientific and Technical Information of China (English)

    李泽林

    2012-01-01

    分析了公路沥青混凝土路面裂缝的类型、形成原因及影响因素,阐述了裂缝对路面的危害,提出了对沥青路面裂缝的预防措施与处治方法,并分别作了具体介绍,以期指导实践。%This paper analysed the crack types, formation causes and influence factors of highway asphalt concrete pavement, elaborated the harm of cracks to pavement, proposed to the prevention measures and treatment methods to asphalt pavement cracks, and made detailed introduction, in order to guide practice.

  8. Impact of SBS modified agent upon asphalt performance%SBS 改性剂对沥青性能的影响

    Institute of Scientific and Technical Information of China (English)

    田艳华

    2014-01-01

    Taking asphalt performance at high and low temperature as the assessing targets,in light of different oil source matrix asphalt and dif-ferent mixing agent with same standard,the paper analyzes the impact of modifier upon different oil source matrix asphalt and the impact of modi-fied mixing amount upon modified asphalt. Results show that:the modified effect of the same modified agent upon different oil source matrix as-phalt is not obvious,modified amount has important impact upon modified asphalt performance,with the increasing of mixing amount,the impact effect is more obvious.%以沥青的高温和低温性能为评价对象,针对相同标号不同油源基质沥青和不同掺量改性剂,分析了改性剂对不同油源基质沥青性能的影响和改性剂掺量对改性沥青性能的影响,结果表明,同一种改性剂对不同油源基质沥青的改性效果不同;改性剂掺量对改性沥青的性能有重要影响,而且掺量越大,影响越显著。

  9. New insights into the effects of styrene-butadiene-styrene polymer modifier on the structure, properties, and performance of asphalt binder: The case of AP-5 asphalt and solvent deasphalting pitch

    Energy Technology Data Exchange (ETDEWEB)

    Nciri, Nader, E-mail: nader.nciri@koreatech.ac.kr [Department of Energy, Materials, and Chemical Engineering, Korea University of Technology and Education, 1600 Chungjeol-ro, Byeongcheon-myeon, Dongnam-gu, Cheonan-City, Chungnam-Province 330-708 (Korea, Republic of); Kim, Namho [Department of Architectural Engineering, Korea University of Technology and Education, 1600 Chungjeol-ro, Byeongcheon-myeon, Dongnam-gu, Cheonan-City, Chungnam-Province 330-708 (Korea, Republic of); Cho, Namjun, E-mail: njuncho@koreatech.ac.kr [Department of Energy, Materials, and Chemical Engineering, Korea University of Technology and Education, 1600 Chungjeol-ro, Byeongcheon-myeon, Dongnam-gu, Cheonan-City, Chungnam-Province 330-708 (Korea, Republic of)

    2017-06-01

    This paper deals with the poorly understood effects of styrene-butadiene-styrene (SBS) copolymer on the bitumen performance. It focuses on determining the impact of various concentrations (e.g., 0, 4, 8, and 12 wt. %) of SBS on the attributes of two types of asphalt namely AP-5 asphalt and solvent deasphalting (SDA) pitch. The unmodified and modified binders were investigated in terms of their chemical compositions, microstructures, thermo-analytical behaviors, and physical properties. The intricate chemical compositions were evaluated by elemental analysis and thin layer chromatography-ionization detection (TLC-FID). Fourier transform infrared (FT-IR) and nuclear magnetic resonance (NMR) spectroscopies, scanning electron microscopy (SEM), and X-ray diffraction (XRD) were utilized to examine the microstructures. Whereas, thermal characteristics were evaluated by thermogravimetric analysis (TGA/DTGA) and differential scanning calorimetry (DSC). The physical behaviors were monitored through the softening point, penetration, viscosity, and ductility tests. The findings showed that the blending of asphalt with different amounts of SBS resulted into different rheological behaviors. This was reflected from the difference in the SARA (i.e., saturates, aromatics, resins, and asphaltenes) compositions and colloidal instability indexes of the modified asphalts. SEM exhibited a continuous asphalt phase with distributed SBS particles, a continuous polymer phase with distributed asphalt globules, or two interconnected continuous phases. FT-IR, {sup 1}H {sup 13}C NMR, and XRD data revealed that the AP-5 asphalt and SDA pitch experienced a number of distinct structural changes. TGA/DSC studies determined the occurrence of diverse events during thermal treatment. It is concluded that the degree of SBS modification depends strongly on SARA composition and polymer content. If the polymers are molded at higher concentrations along with aromatics-rich SDA pitches, then the mixtures

  10. Determination of the heating temperature of potholes surface on road pavement in the process of repairs using hot asphalt concrete mixes

    Directory of Open Access Journals (Sweden)

    Giyasov Botir Iminzhonovich

    2014-12-01

    Full Text Available In the process of roads construction the necessary transport and operational characteristics should be achieved, which depend on the quality of the applied, material and technologies. Under the loads of transport means and the influence of weather conditions on the road pavement deformations and destructions occur, which lead to worsening of transport and operational characteristics, decrease of operational life of the road and they are often the reason of road accidents. According to the data of the Strategic Research Center of "Rosgosstrah" more than 20 % of road accidents in Russia occur due to bad quality of road pavement. One of the main directions in traffic security control and prolongation of operational life for road pavement of non-rigid type is road works, as a result of which defects of pavement are eliminated and in case of timely repairs of high quality the operational life of the road increases for several years. The most widely used material for non-rigid pavement repairs is hot road concrete mixes and in case of adherence to specifications they provide high quality of works. The authors investigate the problems of hot asphalt concrete mixes for repairs of road surfaces of non-rigid type. The results of the study hot asphalt concrete mix’s temperature regimes are offered in case of repair works considering the temperature delivered to the work site and the ambient temperature depending on the type of mix and class of bitumen.

  11. Three-dimensional modeling and simulation of asphalt concrete mixtures based on X-ray CT microstructure images

    Directory of Open Access Journals (Sweden)

    Hainian Wang

    2014-02-01

    Full Text Available X-ray CT (computed tomography was used to scan asphalt mixture specimen to obtain high resolution continuous cross-section images and the meso-structure. According to the theory of three-dimensional (3D reconstruction, the 3D reconstruction algorithm was investigated in this paper. The key to the reconstruction technique is the acquisition of the voxel positions and the relationship between the pixel element and node. Three-dimensional numerical model of asphalt mixture specimen was created by a self-developed program. A splitting test was conducted to predict the stress distributions of the asphalt mixture and verify the rationality of the 3D model.

  12. Polymer-modified Concrete with Improved Flexural Toughness and Mechanism Analysis

    Institute of Scientific and Technical Information of China (English)

    CAO Qingyu; SUN Wei; GUO Liping; ZHANG Guorong

    2012-01-01

    By selecting different types of polymer mixing into concrete,the toughness of concrete is investigated,and results indicate polymer has obvious effect to improve the toughness of concrete.Microstructure of polymer-modified concrete were studied through environment scanning electron microscope and digital micro-hardness tester,results show that polymer acts as a flexible filler and reinforcement in concrete,and alters the microstructure at mortar and ITZ.By crack path prediction and energy consumption analysis,the crack path of polymer-modified concrete is more tortuous and consumes more energy than that of ordinary concrete.

  13. Relationship between fatigue life of asphalt concrete and polypropylene/polyester fibers using artificial neural network and genetic algorithm

    Institute of Scientific and Technical Information of China (English)

    Morteza Vadood; Majid Safar Johari; Ali Reza Rahai

    2015-01-01

    While various kinds of fibers are used to improve the hot mix asphalt (HMA) performance, a few works have been undertaken on the hybrid fiber-reinforced HMA. Therefore, the fatigue life of modified HMA samples using polypropylene and polyester fibers was evaluated and two models namely regression and artificial neural network (ANN) were used to predict the fatigue life based on the fibers parameters. As ANN contains many parameters such as the number of hidden layers which directly influence the prediction accuracy, genetic algorithm (GA) was used to solve optimization problem for ANN. Moreover, the trial and error method was used to optimize the GA parameters such as the population size. The comparison of the results obtained from regression and optimized ANN with GA shows that the two-hidden-layer ANN with two and five neurons in the first and second hidden layers, respectively, can predict the fatigue life of fiber-reinforced HMA with high accuracy (correlation coefficient of 0.96).

  14. Dynamic Response Analysis with 3D Finite Element Method for Two Typical Kinds of Asphalt Concrete Pavements with Saturated Asphalt Layer%两种典型沥青混凝土路面结构沥青层饱水状态动力响应三维有限元分析

    Institute of Scientific and Technical Information of China (English)

    任瑞波; 祁文洋; 徐强

    2011-01-01

    水和动态荷载耦合作用是沥青混凝土路面发生水损害的主要原因.首先基于多孔介质理论,假定路面结构中的沥青混凝土材料为完全饱水的多孔介质材料,对两种典型路面结构--半刚性沥青混凝土路面、具有柔性基层的半刚性沥青混凝土路面分别建立了三维有限元模型;而后对比分析了两种路面结构在动态荷载作用下的竖向应力、竖向应变、孔隙水压力的空间分布情况以及时程变化规律.结果表明:具有柔性基层的半剐性沥青混凝土路面结构具有较好的抗水损害性能,半刚性沥青混凝土路面结构则表现出较差的抗水损害性能.%The coupled moisture-loading action is the primary factor of initial failure for asphalt concrete pavement. At first, based on the porous media theory , assuming the asphalt concrete as saturated porous media material,two three-dimensional finite element models are established for two typical kinds of asphalt concrete pavements which included the semi-rigid base asphalt concrete pavement, the semi-rigid base asphalt concrete pavement with flexible base. Then the comparison and analysis of the spatial distribution and time change regulation for asphalt concrete pavement between the two kinds of structures are carried out which included vertical stress, vertical strain, and pore pressure. The result indicates that the semi-rigid asphalt concrete pavement stucture with flexible base shows the best performance of resisting the moisture damage, relatively the semi-rigid asphalt pavement structure gives the worse performance.

  15. Evaluation of Hydrated Lime Filler in Asphalt Mixtures

    Directory of Open Access Journals (Sweden)

    Mohammed Abbas Hasan Al-Jumaily

    2008-01-01

    Full Text Available Mineral filler is one of important materials and affecting on properties and quality of asphalt mixtures .There are different types of mineral filler depended on cost and quality , the matter encourages us to achieve this study to evaluate hydrated lime filler effects on properties of asphalt mixes related with strength and durability. Conventional asphaltic concrete mixtures with Portland cement and soft sandstone fillers and mixtures modified with hydrated lime were evaluated for their fundamental engineering properties as defined by Marshall properties , index of retained strength , indirect tensile strength , permanent deformation characteristics , and fatigue resistance .A typical dense graded mixture employed in construction of surface course pavement in Iraq in accordance with SCRB specifications was used .The materials used in this study included mineral aggregate materials (coarse and fine sizes were originally obtained from Najaf Sea quarries and two grades of asphalt cements produced from Daurah refinery which are D47 and D66 . The physical properties , stiffness modulus and chemical composition are evaluated for the recovered asphalt cement from prepared asphalt mixes containing various filler types .The paper results indicated that the addition of hydrated lime as mineral filler improved the permanent deformation characteristics and fatigue life and the use of hydrated lime will decrease the moisture susceptibility of the asphalt mixtures.

  16. A new modifier for asphalt waterproof material%一种新型沥青防水材料改性剂

    Institute of Scientific and Technical Information of China (English)

    范新宇; 孔繁和

    2001-01-01

    The influence of environmental status and process thought on asphalt waterproof material is presented.The asphalt performance is improved by means of interior preparation, exterior addition, blowing (oxdation) and dosing raw material of asphalt. The asphalt is modified by addition process of high molecule polymer. This article introduces a new asphalt madifier with main compositions of ethylene acrylate n- butyl ester and glycidyl methacrylate co- polymer. The asphalt modification is achieved through chemical reaction between the copolymer and asphalt.%介绍环境气候、工艺思路对沥青防水材料的影响 ,通过内配法、外掺法、吹制(氧化)沥青及调配沥青的原料, 达到改善沥青性能的方法;掺加高分子聚合物改性石油沥青 的方法及改性性能。较详细介绍一种新的沥青改性剂,它的主 要成份为乙烯丙烯酸正丁脂和甲基丙烯酸缩水甘油脂共聚物 ,通过与沥青之间产生化学反应达到对沥青改性的目的。

  17. Experimental Research on Surface Characteristics of Epoxy Asphalt Concrete Pavement%环氧沥青混凝土铺装表面特性试验研究

    Institute of Scientific and Technical Information of China (English)

    罗桑; 钱振东

    2012-01-01

    To evaluate the surface characteristics of epoxy asphalt concrete pavement,the permeability test,dynamic friction test,Cantabro test,Hamburg test,and laser texture scanning test were conducted.Results show that the coefficient of water permeability of epoxy asphalt concrete is zero,the british pendulum number is 83.6,the mass abrasion rate is 12.5%,the mean profile depth is 0.305 mm,and the estimated texture depth is 0.432 mm.Results show that the water is held into steel deck,because the waterproof performance of epoxy asphalt concrete pavement is excellent.The skid resistance is qualified for the design of bridge deck pavements,but skid of a vehicle occurs when the speed of the vehicle is high on rainy days.Raveling happens under high-temperature water and tire contact loading.The smoothness of epoxy asphalt concrete pavement is good.The surface characteristics of epoxy asphalt concrete pavement satisfy design requirement.However,skid and raveling occur under adverse weather conditions.%为了解环氧沥青混凝土铺装的表面特性,采用渗透性试验、摆式摩擦系数试验、动态摩擦系数试验、肯塔堡飞散试验、汉堡车辙试验和激光纹理扫描试验,对环氧沥青混凝土铺装的渗水性能、抗滑性能、抗松散性能以及表面纹理特征等表面特性进行了试验评价.试验结果显示,环氧沥青混凝土铺装的渗水系数基本为0,摆式摩擦系数为83.6,飞散损失率为12.5%,轮廓深度平均值为0.305 mm,纹理深度估计值为0.432 mm.研究表明,环氧沥青混凝土铺装密水性好,能有效阻止雨水侵蚀钢桥面板;抗滑性能满足设计要求,但在雨天车辆行驶速度高时,易出现车辆打滑现象;抗松散能力较好,但在高温水浴和钢轮轮载的双重作用下,混合料会出现松散和剥落情况;环氧沥青混凝土铺装表面平整度好.环氧沥青混凝土铺装层表面特性符合钢桥面铺装层的设计使用要求,但在不利天气条件下,

  18. The increase of compressive strength of natural polymer modified concrete with Moringa oleifera

    Science.gov (United States)

    Susilorini, Rr. M. I. Retno; Santosa, Budi; Rejeki, V. G. Sri; Riangsari, M. F. Devita; Hananta, Yan's. Dianaga

    2017-03-01

    Polymer modified concrete is one of some concrete technology innovations to meet the need of strong and durable concrete. Previous research found that Moringa oleifera can be applied as natural polymer modifiers into mortars. Natural polymer modified mortar using Moringa oleifera is proven to increase their compressive strength significantly. In this resesearch, Moringa oleifera seeds have been grinded and added into concrete mix for natural polymer modified concrete, based on the optimum composition of previous research. The research investigated the increase of compressive strength of polymer modified concrete with Moringa oleifera as natural polymer modifiers. There were 3 compositions of natural polymer modified concrete with Moringa oleifera referred to previous research optimum compositions. Several cylinder of 10 cm x 20 cm specimens were produced and tested for compressive strength at age 7, 14, and, 28 days. The research meets conclusions: (1) Natural polymer modified concrete with Moringa oleifera, with and without skin, has higher compressive strength compared to natural polymer modified mortar with Moringa oleifera and also control specimens; (2) Natural polymer modified concrete with Moringa oleifera without skin is achieved by specimens contains Moringa oleifera that is 0.2% of cement weight; and (3) The compressive strength increase of natural polymer modified concrete with Moringa oleifera without skin is about 168.11-221.29% compared to control specimens

  19. The crack growth mechanism in asphaltic mixes

    NARCIS (Netherlands)

    Jacobs, .M.M.J.; Hopman, P.C.; Molenaar, A.A.A.

    1995-01-01

    The crack growth mechanism in asphalt concrete (Ac) mixes is studied. In cyclic tests on several asphaltic mixes crack growth is measured, both with crack foils and with cOD-gauges. It is found that crack growth in asphaltic mixes is described by three processes which are parallel in time: cohesive

  20. Relationship between Microstructure and Storage Stability of Modified Asphalt%改性沥青微观结构与储存稳定性的关系

    Institute of Scientific and Technical Information of China (English)

    严秋荣; 王建壮; 孔令云

    2015-01-01

    In accordance with the principle of fluorescence optical microscopy,morphology analysis of polymer modified asphalt and the mixed principle of modified asphalt,etc.,this paper carries out micro-observation for samples during preparation of modified asphalt with different types of SBS modifiers and asphalt of the same matrix,and meanwhile takes photos of its morphologies in different periods of time, and studies the relationship between morphologies and storage stability of modified asphalt in combination with the results of micro -observation and the results of separation test for modified asphalt.The study shows that analysis for existing morphologies of polymer modifiers during preparation of modified asphalt can provide bases for preparation temperature and time,etc.of modified asphalt;the easier the polymer modifiers is mixed in asphalt and the smaller the particle size,the better the stability of the prepared modified asphalt and the more remarkable the improvement of softening point;for asphalt of the same matrix,SBS modifier at larger block ratio shows good modified effect on matrix asphalt,and the stability of the prepared modified asphalt is better.%根据荧光显微照相原理、聚合物改性沥青的相态结构分析、改性沥青的混合原理等,对不同型号的SBS改性剂与同一基质沥青配制改性沥青过程中的样品进行显微观测,同时对其不同时段的相态结构进行照片拍摄,并结合微观观测结果与改性沥青离析试验结果,对改性沥青的相态结构与其存储稳定性之间的关系进行研究。研究表明:分析改性沥青制备过程中聚合物改性剂的存在相态,可为改性沥青制备温度、时间等提供依据;聚合物改性剂在沥青中越容易混合、粒径越小,所制备的改性沥青的稳定性越好,软化点的提高越显著;对同一基质沥青,嵌段比大的SBS改性剂对基质沥青的改性效果好,所制备的改性沥青稳定性更好。

  1. The urban heat island effect, its causes, and mitigation, with reference to the thermal properties of asphalt concrete.

    Science.gov (United States)

    Mohajerani, Abbas; Bakaric, Jason; Jeffrey-Bailey, Tristan

    2017-07-15

    The Urban Heat Island (UHI) is a phenomenon that affects many millions of people worldwide. The higher temperatures experienced in urban areas compared to the surrounding countryside has enormous consequences for the health and wellbeing of people living in cities. The increased use of manmade materials and increased anthropogenic heat production are the main causes of the UHI. This has led to the understanding that increased urbanisation is the primary cause of the urban heat island. The UHI effect also leads to increased energy needs that further contribute to the heating of our urban landscape, and the associated environmental and public health consequences. Pavements and roofs dominate the urban surface exposed to solar irradiation. This review article outlines the contribution that pavements make to the UHI effect and analyses localized and citywide mitigation strategies against the UHI. Asphalt Concrete (AC) is one of the most common pavement surfacing materials and is a significant contributor to the UHI. Densely graded AC has low albedo and high volumetric heat capacity, which results in surface temperatures reaching upwards of 60 °C on hot summer days. Cooling the surface of a pavement by utilizing cool pavements has been a consistent theme in recent literature. Cool pavements can be reflective or evaporative. However, the urban geometry and local atmospheric conditions should dictate whether or not these mitigation strategies should be used. Otherwise both of these pavements can actually increase the UHI effect. Increasing the prevalence of green spaces through the installation of street trees, city parks and rooftop gardens has consistently demonstrated a reduction in the UHI effect. Green spaces also increase the cooling effect derived from water and wind sources. This literature review demonstrates that UHI mitigation techniques are best used in combination with each other. As a result of the study, it was concluded that the current mitigation

  2. Numerical Analysis on Multi-scale Structure of Asphalt Concrete Pavement%沥青路面多尺度结构的荷载响应分析

    Institute of Scientific and Technical Information of China (English)

    陈俊; 黄晓明

    2012-01-01

    In order to explore the stress and strain relation in the pavement layers under traffic load from a meso-structural perspective, the single-scale discrete element model of asphalt pavement structure was built using discrete element method (DEM). The stress and strain at the bottom of the asphalt concrete layer under vertical load were calculated. The validation of discrete element model of asphalt pavement structure was conducted by the comparison of discrete element prediction with the results from the classical program. The distribution and volumetric fraction of coarse aggregate, asphalt mastic and air voids were taken into consideration at the bottom of the asphalt layer in the validated discrete element model to build the multi-scale structure of asphalt concrete pavement. The tensile stress and strain in asphalt mastics and interface between aggregate and mastic were obtained and compared with the results from the single-scale model. Results show that the stress and strain in multi-scale structure is heterogeneous distribution. The tensile stress at the interface between aggregate and mastic is much higher than that in mastic. The ratio of stress at interfaces to the stress in mastics increases as the mastic stiffness decreases. The pavement design based on single-scale model may underestimate the tensile stress at interface between aggregate and mastic and overestimate the tensile stress in mastic.%为了从材料细观结构角度研究沥青路面结构的荷载响应,采用离散元方法,建立了柔性基层沥青路面典型结构模型,并进行了竖向荷载作用下沥青混凝土层应力和应变的计算,通过与经典路面响应程序计算结果的比较,验证了路面结构离散元模型和离散元计算方法的正确性.以验证过的路面结构模型为基础,采用较小的细观尺度描述了沥青混凝土结构层底部位置处粗集料、沥青砂浆和空隙的分布和体积大小,从而建立了路面结构的多尺度模

  3. Preparation of Nano-modified Asphalt and Its Road Performance Evaluation%纳米改性沥青制备和路用性能研究

    Institute of Scientific and Technical Information of China (English)

    孙璐; 朱浩然; 辛宪涛; 王鸿遥; 顾文钧

    2013-01-01

    In order to improve the road performance of base asphalt, nano-Ⅰ was used as a modifier, and A, B and C were separately used as dispersants to prepare nano-modified asphalt and the road performance of those asphalts was evaluated. In addition, nano-Ⅰ and SBS compound modified asphalt was also prepared to study the effect of nano- I on the polymer modified asphalt. Among all types of nano-Ⅰ modified asphalt, the cases with outstanding performance were selected to conduct DSR and BBR tests to further evaluate their road performance. The results show that nano-Ⅰ can significantly improve the high temperature performance of asphalt; surface modification of nano-Ⅰ particles has a significant effect on asphalt performance, so it is necessary to develop a surface modification technology suitable for asphalt modification to realize the nano-effect completely; nano-Ⅰ can further improve both the high temperature and low temperature performance of SBS modified asphalt.%为提高基质沥青的路用性能,采用纳米Ⅰ作为改性剂,并选用A,B和C作为分散剂,制备了纳米改性沥青并进行路用性能评价;同时将纳米工与SBS复合进行沥青改性,以考察纳米Ⅰ对聚合物改性沥青性能的影响.对其中的优选改性方案,进行DSR和BBR试验,进一步评价其路用性能.结果表明:纳米Ⅰ可以明显改善沥青的性能,使沥青的高温性能得以显著提高;纳米粒子的表面改性对沥青的性能有显著影响,有必要开发适用于沥青的纳米粒子表面改性方案,以充分发挥粒子的纳米效应;纳米Ⅰ对SBS改性沥青的影响表现为高、低温路用性能的全面提高.

  4. 试析高速公路工程中改性沥青的应用%Study on the Application of Modified Asphalt in Expressway Engineering

    Institute of Scientific and Technical Information of China (English)

    余新日

    2011-01-01

    With the rapid development of transport and rapid growth of traffic, modified asphalt is more and more widely used in the highway,modified asphalt starts late in China, but excellent road performance brought by the modified asphalt has been recognized and valued by people, the paper analyzes the performance of different types of modified asphalt, the use environment and production efficiency, which provides a valuable reference for the application of modified asphalt in highway.%随着交通事业的蓬勃发展,交通流量快速增长,改性沥青在高速公路的应用也越来越广泛,在我国,改性沥青的研究起步较晚,但沥青改性所带来的优良的路用性能已经受到了人们的认可和重视,本文通过分析不同种类改性沥青的性能、使用环境、生产效率等,为改性沥青在高速公路的应用提供有价值的参考.

  5. The improvement of pavement performance using asphalt rubber hot mixes

    OpenAIRE

    Pais, Jorge C.; Pereira, Paulo A. A.

    2007-01-01

    The need of a better pavement performance has led researchers to develop new road materials, mainly for the asphalt layers, where the modification of the asphalt is the main example. This modification usually forces the use of polymers and fibers and, more recently, the use of crumb rubber from ground tires, where the modified asphalt is known as asphalt rubber. This asphalt rubber used in asphalt mixtures produces a superior performance if compared to the asphalt mixtures with...

  6. TLA 改性沥青的高温流变性能研究%Research on the Temperature Rheological Properties of TLA Modified Asphalt

    Institute of Scientific and Technical Information of China (English)

    杨娥

    2012-01-01

      This paper applies dynamic mechanical analysis method to study the dynamic rheological properties of common asphalt and TLA modified asphalt in high -temperature; and measures the temperature and frequency pa -rameters of the dynamic rheological properties within a certain range ; and analyses the impact of the variation of the rheological properties of asphalt TLA through the analysis of different dosage TLA modified asphalt dynamic per -formance parameters.The results show that: after adding TLA increased asphalt complex modulus , phase angle de-creases while asphalt rutting factor increases .%  采用动态力学分析方法对基质沥青和 TLA 改性沥青的高温动态流变性能进行研究,测定了一定温度和频率范围内的动态流变性能参数,并通过分析 TLA 掺量不同的改性沥青的动态性能参数变化规律来分析 TLA 对沥青的流变性能的影响,结果表明:加入 TLA 后沥青复数模量增大,相位角减小,沥青的车辙因子相应增大。

  7. Estudo de misturas asfálticas com ligante modificado pelo polímero EVA para pavimentos urbanos de Manaus - AM Study of asphalt mixtures containing a binder modified with EVA polymer for use in urban pavements in Manaus

    Directory of Open Access Journals (Sweden)

    Daniela M. G. D'Antona

    2011-01-01

    Full Text Available A presente pesquisa buscou soluções com materiais alternativos visando à construção de pavimentos urbanos para Manaus (AM com maior vida útil e condizente com as suas condições de serviço, em particular, o seu desempenho mecânico frente às temperaturas regionais. Estudou-se o ligante regional, CAP 50/70, misturado com 4% do polímero EVA, e como partícipe em compósitos asfálticos. A incorporação do mencionado polímero teve como objetivo melhorar suas propriedades reológicas e, por conseguinte, o comportamento mecânico desse compósito - concreto asfáltico, empregado como revestimento nas vias urbanas da Capital do Estado do Amazonas. Os ligantes (virgem e modificado foram caracterizados conforme a especificação da ANP e a metodologia Superpave. As misturas asfálticas foram avaliadas pelo ensaio de fluência por compressão axial, com carregamento dinâmico à temperatura de 40 ºC. O material asfáltico modificado com EVA (AMP EVA demonstrou melhores propriedades reológicas ou equivalentes ao asfalto convencional (REMAN, ao longo de todos os ensaios de caracterização. As misturas alternativas compostas com o CAP modificado (SEVA obtiveram desempenho mecânico superior ao de misturas com cimento asfáltico habitualmente comercializado na região (SMAN.In this research we investigated alternative materials to build urban pavements in Manaus, seeking for pavements with longer lifetime for usage and suitable mechanical properties to withstand the local temperatures. The asphaltic mixtures contained a regional binder, namely CAP 50/70, mixed with 4% of EVA polymer. The incorporation of the latter polymer was aimed at improving the rheological properties of asphaltic concrete used in roads in the Amazonas' capital. The asphalt binders (original and modified were characterized in accordance with the ANP (National Petroleum Agency specification and the Superpave methodology. The asphalt mixtures had their mechanical properties

  8. SBS改性沥青老化及再生技术研究%Research on SBS Modified Asphalt Aging and Recycling Technology

    Institute of Scientific and Technical Information of China (English)

    窦刚玉; 陈静云

    2011-01-01

    分析SBS改性沥青老化再生研究的重点、难点,通过对比沥青老化前后化学组分与物理性质变化,结合国内外研究成果,总结SBS改性沥青老化机理,归纳沥青老化理论;而后依靠组分调节理论与相容性理论,指出SBS改性沥青再生的方向,通过试验和理论两方面证实传统沥青再生技术适合于改性沥青再生利用。%The key points and difficulties of SBS modified asphalt aging and recycling research are analyzed.Through the comparison of chemical component and physical property changes before and after aging and combined with the research results at home and abroad,SBS modified asphalt aging mechanism and theory are summarized.Based on component regulatory theory and compatibility theory,recycling direction of SBS modified asphalt is pointed out.The experiment and theory both show that recycling technology for traditional asphalt is suitable for the recycling utilization of modified asphalt.

  9. 新型反应性改性沥青改性剂技术性能研究%Study on Properties of Reactive Asphalt Modifiers

    Institute of Scientific and Technical Information of China (English)

    曹晓娟

    2015-01-01

    对不同种类改性沥青混合料进行了动态模量试验、小梁弯曲疲劳试验、动态蠕变拉伸试验和无侧限拉伸试验,通过对这四种试验结果进行分析研究,对比了不同种类改性沥青混合料的技术性能,评价了 RET改性剂对沥青混合料路用性能的改善效果。%Different types of modified asphalt mixtures were analyzed by dynamic modulus test, beam bending fatigue test, dynamic creep tests and double-edge-notched tension test, technical properties of different types of modified asphalt mixtures were compared, improvement effect of RET modifier for asphalt pavement performance was evaluated.

  10. Experimental Study on Shear Fatigue Behavior and Stiffness Performance of Warm Mix Asphalt by adding Synthetic Wax

    OpenAIRE

    Petit, Christophe; Millien, Anne; Canestrari, Francesco; Pannunzio, Valter; Virgili, Amadeo

    2012-01-01

    Synthetic waxes produced by standard and registered processes may be used to manufacture Warm Mix Asphalt (WMA), which is a modified asphalt concrete produced, applied and compacted at temperatures below those typically required. This feature leads to environmental benefits, such as reduced energy consumption, gas and fume emissions, as well as to economic/operational advantages, such as lower production costs and greater hauling distances for extended construction seasons with tighter schedu...

  11. Experimental Study on Shear Fatigue Behavior and Stiffness Performance of Warm Mix Asphalt by adding Synthetic Wax

    OpenAIRE

    Petit, Christophe; Millien, Anne; Canestrari, Francesco; Pannunzio, Valter; Virgili, Amadeo

    2012-01-01

    International audience; Synthetic waxes produced by standard and registered processes may be used to manufacture Warm Mix Asphalt (WMA), which is a modified asphalt concrete produced, applied and compacted at temperatures below those typically required. This feature leads to environmental benefits, such as reduced energy consumption, gas and fume emissions, as well as to economic/operational advantages, such as lower production costs and greater hauling distances for extended construction sea...

  12. INVESTIGATION OF RHEOLOGICAL PROPERTIES OF MODIFIED BITUMEN

    Directory of Open Access Journals (Sweden)

    Erofeev Vladimir Trofimovich

    2016-08-01

    Full Text Available At the present time the most widely used type of road pavement is asphalt-concrete pavement produced on the basis of oil bitumen. One of the efficient ways to increase the quality and durability of asphalt-concrete pavement is modification of bitumen. Though Russian specialists still don’t have the global view of the ideal and real asphalt cement, the requirements to its quality and durability indicators in the composition of road structure haven’t yet formed. The authors present the investigation results of the properties of oil asphalt cement containing 0.5-2.0% of modifier “Olazol”. The physical, mechanical and rheological properties of the modified bitumen are determined. The dependences of the dynamic viscosity of the modified bitumen from the quantity of introduced modifier, shear rate and reheat temperature are analyzed.

  13. RESEARCH OF THE STRESS STATE OF A MODIFIED IN-SITU CONCRETE

    Directory of Open Access Journals (Sweden)

    D. V. Rudenko

    2016-12-01

    Full Text Available Purpose. The article focuses on investigation of the stress state of a modified in-situ concrete of natural hardening. Methodology. To achieve the aim, the research of the microstructure of the modified cement matrix of concrete, as well as the mechanism of structure formation of modified concrete with natural hardening was conducted; the methods for reliable evaluation of concrete strength were defined. Findings. The development of internal stresses affects the properties of concretedifferently. With an increase in temperature-shrinkage deformations in time and, thus, with increasing structural stresses in the cement sheath around the grains of the filler two opposite processes may develop: zone of plastic flow or cracking. Originality. It was established that the structural features complex of the modified concrete when the load transfer leads to the formation of extensive zones of prefracture which is able to absorb a significant amount of elastic strain energy that provides the design deformation properties of the concrete for special purposes. Ideas about the definition of the criteria of cracking modified concrete, hardening under natural conditions had further development. Practical value. The resulting equations allow to solve the problem about the minimum level of structural stress in monolithic concrete in a saturated large placeholder, as well as to assess the influence of structural stresses on the properties of concrete. In normal concrete with a relatively thin cement sheath at temperature-shrinkage deformations, high tangential and low radial tension occur. In vivo, this stress is higher as a result of higher values of Δε(τ, which is not observed in the modified concrete. In the modified concretes only tangential stresses are the greatest danger to structures. The change of shrinkage stress with time is straightforward. The total temperature-shrinkage deformations have a sawtooth graph. For modified concrete the amplitude is 48

  14. USE OF RECLAIMED ASPHALT PAVEMENT WITH MILLED ROAD PAVEMENT LAYERS

    OpenAIRE

    Andrzej Plewa; Marta Wasilewska; Władysław Gardziejczyk; Paweł Gierasimiuk

    2015-01-01

    The article presents the results of research on the functional properties of asphalt mixes using RAP obtained from milling asphalt road pavements. Asphalt concrete AC 22P with 0%, 10%, 15% and 20% addition of RAP used for base course of road pavements were designed. It was found that asphalt mixes with RAP characterized by comparable and in some cases better functional properties compared to the asphalt mixes without RAP (0%). One should notice the influence of RAP on the performance and ...

  15. POE弹性体改性沥青的结构与性能%Structure and properties of POE modified asphalt

    Institute of Scientific and Technical Information of China (English)

    谢玉阁; 姚鸿儒; 黄健

    2013-01-01

    研究了聚烯烃弹性体(POE)改性沥青的结构和性能,考察了POE用量对两种基质沥青常规性能的影响,并用光学显微镜观察了POE在沥青中的分布状态.结果表明,随着POE用量增加,沥青的软化点增加,25℃针入度减小,高温性能变好.通过储存稳定性实验发现,POE改性沥青后稳定性较差.POE改性沥青相结构研究发现,随着POE用量的增加,POE由分散相变为连续相,POE质量分数为6%时,基质沥青发生相转变.%Polyolefin elastomer (POE) modified asphalt was studied.Two different base asphalts were mixed with POE at various contents.The properties and morphology of the modified asphalt were characterized by classical test methods and optical microscope.The results indicated that POE could improve the conventional properties of base asphalt,while the hot storage stable tests showed a poor compatibility with asphalt.The research of the phase structure showed that,dispersed POE granules changed to continuous phase with its increasing content,the phase transition began at about 6 % polymer content.

  16. Nu merical simulation on electrothermal properties of geogrid reinforced asphalt concrete%格栅增强沥青混凝土电热性能数值模拟

    Institute of Scientific and Technical Information of China (English)

    宋世德; 周卫杰

    2016-01-01

    Carbon/glass fiber geogrid reinforced asphalt concrete is a new type of composite,which not only has good mechanical properties,but also shows excellent electrical conductivity.In this paper,the good electrother-mal properties of carbon/glass fiber geogrid reinforced asphalt concrete were used to heat the asphalt concrete slab,then melt snow and deice the ice.The environment temperature,the wind speed,the heating power and the thickness of ice are four main factors of the asphalt concrete slab deicing efficiency.In this paper,the deicing process of carbon/glass fiber geogrid reinforced asphalt concrete were simulated by ANSYS finite element software to predict deicing effect.The experimental values were used to verify the correctness of the numerical simulation. The results show that under various operating conditions,the numerical values are very close to the experimental values in the deicing process of carbon/glass fiber geogrid reinforced asphalt concrete.%利用碳/玻璃纤维格栅增强沥青混凝土的良好电热性能,使沥青混凝土板升温起到融雪化冰的作用。环境温度、风速、发热功率和冰层厚度是影响沥青混凝土板化冰效率的4个主要因素。应用ANSYS有限元软件对碳/玻璃纤维格栅增强沥青混凝土的化冰过程进行数值模拟来预测其化冰效果,并用试验结果验证有限元模拟的正确性。结果表明:在各种工况下,碳/玻璃纤维格栅增强沥青混凝土化冰过程的模拟值与试验值的吻合度比较高。

  17. On analysis of roadbed damage features of asphalt concrete of heavy traffic%重载交通沥青混凝土路面损坏特征分析

    Institute of Scientific and Technical Information of China (English)

    张丽娟

    2012-01-01

    According to the site investigation and document collection,the paper investigates the typical damages on the asphalt roadbed,analyzes and sums up the damage types and features of the asphalt concrete roadbed structure under the heavy traffic,so as to provide the theoretic reference for the asphalt damage issue in heavy traffic.%通过现场实地调研和资料收集,调查了沥青路面的典型损坏状况,分析并总结了重载交通下沥青混凝土路面结构损坏类型和损坏特征,为解决重载沥青损坏问题提供了理论依据。

  18. Study on Property of Castor Oil Based Polyurethane Modified Asphalt%蓖麻油基聚氨酯改性沥青的性能研究

    Institute of Scientific and Technical Information of China (English)

    夏磊; 张海燕; 曹东伟; 郭燕生

    2016-01-01

    To develop a new type of modified asphalt and its preparation process, the castor oil contained asphalt is obtained with green renewable castor oil instead of petroleum based polyols at first, then the second monomer liquefied MDI is slowly dropped into pitch system with shearing and the castor oil based polyurethane ( PU) modified asphalt is prepared. The dosage of castor oil and the second monomer MDI are calculated by isocyanate index R( -NCO/ -OH) =1. 8, and the modified asphalt with 10% -30% content of castor oil based PU are synthesized. The performance of modified asphalt are characterized by conventional experiment. The experiment result shows that the modifier in asphalt dispersed evenly and both the high and low temperature performance of the castor oil based PU modified asphalt are improved, especially the high temperature performance. The high temperature grade of asphalt is determined by the original grade test and thin film oven tests ( TFOT) grade test on the samples. On the basis of high temperature grade, the high temperature performances of different asphalts after aging are analysed and evaluated by multiple stress creep recovery ( MSCR) test. The result shows that the creep compliance of the modified asphalt declined greatly and recovery rate raised obviously compared with base asphalt, which effectively achieved the effect of increasing elasticity and stiffening. With the increase of the modifier dosage, creep compliance declined and recovery rate raised in the same time, the modification effect is better.%为开发一种新型改性沥青及其制备工艺,以绿色可再生的蓖麻油代替石油基多元醇,先制成含油沥青,在沥青体系中再缓慢滴加第二单体液化二苯基甲烷二异氰酸酯(MDI),边剪切边制成蓖麻油基聚氨酯改性沥青.通过异氰酸酯指数R(-NCO/-OH)=1.8,按10%~30%总体改性剂掺量,计算出蓖麻油及第二单体MDI的用量,分别制备10%~30%的蓖麻油基聚氨酯改性沥青.通

  19. Evolution of the microstructure of unmodified and polymer modified asphalt binders with aging in an accelerated weathering tester.

    Science.gov (United States)

    Menapace, Ilaria; Masad, Eyad

    2016-09-01

    This paper presents findings on the evolution of the surface microstructure of two asphalt binders, one unmodified and one polymer modified, directly exposed to aging agents with increasing durations. The aging is performed using an accelerated weathering tester, where ultraviolet radiation, oxygen and an increased temperature are applied to the asphalt binder surface. Ultraviolet and dark cycles, which simulated the succession of day and night, alternated during the aging process, and also the temperature varied, which corresponded to typical summer day and night temperatures registered in the state of Qatar. Direct aging of an exposed binder surface is more effective in showing microstructural modifications than previously applied protocols, which involved the heat treatment of binders previously aged with standardized methods. With the new protocol, any molecular rearrangements in the binder surface after aging induced by the heat treatment is prevented. Optical photos show the rippling and degradation of the binder surface due to aging. Microstructure images obtained by means of atomic force microscopy show gradual alteration of the surface due to aging. The original relatively flat microstructure was substituted with a profoundly different microstructure, which significantly protrudes from the surface, and is characterized by various shapes, such as rods, round structures and finally 'flower' or 'leaf' structures.

  20. Nanomaterials Applied in Asphalt Modification: A Review

    Institute of Scientific and Technical Information of China (English)

    Changqing Fang; Ruien Yu; Shaolong Liu; Yan Li

    2013-01-01

    Nanotechnology has been gradually penetrated into the field of asphalt modification.Seemingly magic effects of nanomaterials have now been brought to improve the performance of asphalt.To demonstrate many of the prospective applications,researchers have conducted a series of positive and effective efforts dealing with the preparation of modified asphalt to demonstrate the mechanism of modification and the resultant improvement in performance.In this review,various nanomaterials used in asphalt modification are initially presented,followed by the methods employed to modify the asphalt with these materials and finally the effects of nanomaterials on the performance of base asphalt are presented and the modification mechanisms are discussed.Based on the current research results,the influence of preparation process parameters on the compatibility of every phase in the modified asphalt and the stability of the modified asphalt system are described.Finally,the development trend of the topic field is projected.

  1. Dynamic Modulus Test Analysis of Sulfur Modified Asphalt Mixture%硫磺改性沥青混合料的动态模量试验分析

    Institute of Scientific and Technical Information of China (English)

    侯睿; 郭忠印

    2013-01-01

    UTM system was used to test asphalt mixture's dynamic modulus with different sulfur contents (by mass).The influences of temperature,loading frequency and sulfur content on the viscoelastic properties of asphalt mixtures were analyzed.The results show that the temperature and loading frequency have the same influence on dynamic modulus of both sulfur modified asphalt mixture and conventional asphalt mixture.The effect of sulfur contents on viscoelastic properties of asphalt mixtures is different.A small quantity of sulfur will increase asphalt mixture's viscosity and temperature sensitivity,but a large quantity of sulfur will increase asphalt mixture's elasticity and reduce temperature sensitivity.%采用UTM系统对不同硫磺掺量(质量比)的沥青混合料进行动态模量试验,分析了温度、加载频率和硫磺掺量对沥青混合料黏弹特性的影响.结果表明:温度和加载频率对硫磺改性沥青混合料和普通沥青混合料动态模量的影响规律基本相同;不同硫磺掺量对沥青混合料黏弹性能的影响有所不同,硫磺掺量较小时,沥青混合料的黏性增加,温度敏感性增大;硫磺掺量较大时,沥青混合料的弹性增加,温度敏感性降低.

  2. Influence of soft bitumens on the chemical and rheological properties of reclaimed polymer-modified binders from the "old" surface-layer asphalt

    NARCIS (Netherlands)

    Liu, G.; Nielsen, E.; Komacka, J.; Leegwater, G.; Ven, M. van de

    2015-01-01

    Reclaimed asphalt (RA) that contains polymer-modified bitumen (PMB) offers a potential premium material contribution for recycling. This study investigated the influence of soft virgin bitumens on the chemical and rheological properties of three reclaimed PMBs from different "old" surface-layer

  3. USE OF RECLAIMED ASPHALT PAVEMENT WITH MILLED ROAD PAVEMENT LAYERS

    Directory of Open Access Journals (Sweden)

    Andrzej Plewa

    2015-07-01

    Full Text Available The article presents the results of research on the functional properties of asphalt mixes using RAP obtained from milling asphalt road pavements. Asphalt concrete AC 22P with 0%, 10%, 15% and 20% addition of RAP used for base course of road pavements were designed. It was found that asphalt mixes with RAP characterized by comparable and in some cases better functional properties compared to the asphalt mixes without RAP (0%. One should notice the influence of RAP on the performance and durability of the asphalt mixtures, as compared to virgin asphalt mixtures (without RAP.

  4. 土工布在水泥混凝土路面加铺沥青混凝土层结构中的抗剪试验分析%Analysis of Shear-Bearing Test for Geotextile Between Cement Concrete and Asphalt Concrete Overlay

    Institute of Scientific and Technical Information of China (English)

    侯荣国; 牛开民; 田波

    2011-01-01

    在水泥混凝土路面加铺沥青混凝土面层(简称“白加黑”)的路面结构中,利用层间铺设土工布来延缓、减少反射裂缝是一种经常被采用的技术方案.但铺设土工布后,层间黏结力下降,容易造成沥青混凝土加铺层推移而致过早破坏.针对此现象,运用有关力学软件计算分析了水泥混凝土面板与沥青混凝土加铺层结构中的层间剪应力,发现层间光滑时的剪应力大于层间黏结时的剪应力;同时,通过试验路与室内试验,分析了铺有土工布的水泥混凝土面板与沥青混凝土层之间的抗剪能力,发现土工布满足层间抗剪要求,但抗剪富余系数不大,因此铺有土工布的水泥混凝土路面加铺沥青混凝土层的路面结构容易发生推移破坏.%To prevent reflective cracking, the geotextile is often layed between cement concrete pavement and asphalt concrete overlay. But cohesion between two layers is reduced after construction of geotextile, so it creates moving of asphalt concrete overlay. The shear stress between old cement concrete pavement and asphalt concrete overlay is analyzed through finite element model. It is found that shear stress is bigger on the assumption of perfectly smooth compared to the assumption of perfectly junction.Through experiment road and indoor test, shear-bearing capacity between cement concrete pavement and asphalt concrete overlay is analyzed while the geotextile is layed. It is found that the geotextile can satisfy the request for single shear-bearing, but redundancy coefficient is low, so moving of asphalt overlay is created easily when the geotextile is layed between old cement concrete pavement and asphalt concrete overlay.

  5. High-temperature Performance Improvement of Dense-graded Hot Mixing Asphalt Concrete%浅谈提高热拌密级配沥青混凝土的高温性能

    Institute of Scientific and Technical Information of China (English)

    李峰

    2012-01-01

    From improving the dynamic stability of asphalt concrete pavement, the paper explains the mixing content, use and mixing methods of the rutting resistant in mixing asphalt concrete, and after verifying the targeted mixing proportion, proposes treating and improving measures concerning the problems in the experimental mixing.%从提高沥青混凝土路面动稳定度出发,对沥青混凝土(以密级配沥青混凝土AC-20为例)配合比设计中抗车辙剂的掺量、用法、拌和方法进行了分析,并通过沥青混凝土目标配合比的验证,及时针对试验拌和中出现的问题提出处理意见和改进措施。

  6. 土工布在水泥混凝土路面加铺沥青层中的应用%Application of geotextile in cement concrete pavement paving asphalt layer

    Institute of Scientific and Technical Information of China (English)

    王强林

    2011-01-01

    Combining with the application of geotextile in the construction of Gui-Liu highway pavement paving asphalt layer, this paper detailedly elaborated the application of geotextile in cement concrete pavement paving asphalt concrete surface layer, emphatically introduced the materi- al properties and construction technology of geotextile, accumulated valuable experience for future similar projects construction.%结合土工布在桂柳高速公路路面加铺沥青层工程的应用,详细阐述了土工布在水泥混凝土路面加铺沥青混凝土面层中的应用,着重介绍了土工布的材料特性和施工工艺,为今后同类工程施工积累了宝贵经验。

  7. 长寿命沥青混凝土路面结构特点与设计分析%Structural characteristics and design analysis of perpetual asphalt concrete pavements

    Institute of Scientific and Technical Information of China (English)

    张耀将

    2016-01-01

    关于长寿面沥青混凝土路面应用与管理的研究应该形成一个完整的体系,只是对这个话题初步进行了分析了。要加强对沥青混凝土的研究,以路面使用时间短、路面损坏现象严重的问题。%There should be a complete system about the application and management research on perpetual asphalt concrete pavements.This paper preliminarily discusses the topic.It points out that we should strengthen the research of perpetual as-phalt concrete,to solve the problem of use shortly -time -using and badly -damaged pavement.

  8. Influence of Aggregate Coated with Modified Sulfur on the Properties of Cement Concrete

    Directory of Open Access Journals (Sweden)

    Swoo-Heon Lee

    2014-06-01

    Full Text Available This paper proposes the mixing design of concrete having modified sulfur-coated aggregate (MSCA to enhance the durability of Portland cement concrete. The mechanical properties and durability of the proposed MSCA concrete were evaluated experimentally. Melting-modified sulfur was mixed with aggregate in order to coat the aggregate surface at a speed of 20 rpm for 120 s. The MSCA with modified sulfur corresponding to 5% of the cement weight did not significantly affect the flexural strength in a prism concrete beam specimen, regardless of the water-cement ratio (W/C. However, a dosage of more than 7.5% decreased the flexural strength. On the other hand, the MSCA considerably improved the resistance to the sulfuric acid and the freezing-thawing, regardless of the sulfur dosage in the MSCA. The coating modified sulfur of 5% dosage consequently led to good results for the mechanical properties and durability of MSCA concrete.

  9. Research on the Performance of New Reactive Asphalt Modifier%新型反应性沥青改性剂技术性能研究

    Institute of Scientific and Technical Information of China (English)

    曹晓娟

    2015-01-01

    RET 是美国杜邦公司研发的一种新型沥青化学改性剂,通过与沥青中的分子和官能团发生化学反应,从而达到改善沥青使用性能的效果。通过分析研究不同种类改性沥青的 Superpave 性能试验结果及老化前后的低温 PG 分级温度及质量损失,表明 RET 改性剂能够明显改善沥青的高温稳定性和低温抗裂性。%RET(Reactive Elastomeric Terpolymer) is a kind of chemical modifier that was developed by Dupont, it can react with asphalt molecules and functional groups to improve the functional performance of the asphalt. In this paper, Superpave performance test results, low temperature PG grading temperature and mass loss before and after aging of different types of modified asphalt were analyzed and researched. The results show that RET modifier can significantly improve asphalt high temperature stability and low temperature crack resistance.

  10. Analysis of influence of gravel aggregate broken on performance of asphalt concrete core wall%砾石骨料破碎对心墙沥青混凝土的性能影响分析

    Institute of Scientific and Technical Information of China (English)

    仝卫超; 何建新; 王怀义

    2016-01-01

    In view of the problem of choice of coarse aggregate for core wall of asphalt concrete,the paper used natural gravel and broken gravel as coarse aggregate,and took natural river sand as fine aggregate to prepared two kinds of asphalt concrete specimens.It used the method of indoor test to carry out water stability,stretching,compression,bending trabecular penetration,static triaxial tests of asphalt concrete core wall respectively.The results showed that only the compressive and flexural strength of asphalt concrete made from natural gravel coarse aggregate is lower than that from broken aggregate.Natural gravel can be used as the coarse aggregate of mixture ratio priority choice.%针对心墙沥青混凝土中粗骨料的选择问题,本文用天然砾石和破碎砾石作为粗骨料,细骨料均采用天然河砂制备两种沥青混凝土试件.采用室内试验的方法,分别进行沥青混凝土心墙的水稳定性、拉伸、单轴压缩、小梁弯曲、渗透、静三轴试验.结果表明:沥青混凝土用天然砾石做粗骨料仅在抗压、抗弯强度比用破碎骨料低.天然砾石可以作为本次配合比优选的粗骨料.

  11. Mechanical Strength Properties of RCA Concrete Made by a Modified EMV Method

    Directory of Open Access Journals (Sweden)

    Namho Kim

    2016-09-01

    Full Text Available This study used two types of Recycled Concrete Aggregates (RCAs with the same original virgin aggregate, but with different amounts of residual mortars. To verify that the mechanical properties of the concrete were affected by changing the unit volume of residual mortar, fresh mortar, and total mortar of the concrete, a series of paving concrete mixes were made using a modified equivalent mortar volume (EMV mix design, along with a conventional American Concrete Institute (ACI mix design. The test results showed that the RCA concrete with the conventional mix design, which led to a prominent decrease in compressive strength and elastic modulus at each age, had 10% greater total mortar volume than that with the modified EMV mix design. As for the conventional ACI mix, it appears that the replacement ratio of RCA and the volume of the residual mortar in RCA directly affect the modulus of elasticity as well as the compressive strength of concrete. However, for the modified EMV mix, the modulus of elasticity of the concrete may be increased to be equivalent to the companion concrete with natural aggregate by controlling the new mortar volume so that the total mortar volume remains the same regardless of the RCA replacement ratio. It was observed that the smaller new volume requirement makes the RCA paving concrete more environmentally friendly and economically profitable.

  12. The Characteristics of Asphalt Concrete Binder Course (AC-BC Mixture with Bottom Ash as Aggregate Substitute

    Directory of Open Access Journals (Sweden)

    Sugiyanto G.

    2015-01-01

    Full Text Available Highways serve nearly 80-90% of the population mobility and flow of goods. Utilization of bottom ash, a waste from coal combustion, in highway construction is one of the alternatives to reduce environmental pollution and support Clean Development Mechanism Program of Kyoto Protocol. The aim of this study is to analyze the characteristics of AC-BC mixture that uses bottom ash as partial substitute of fine aggregate and comparing with a standard mixture. Laboratory tests are performed on two different types of mixtures. The tests show that optimum asphalt content for AC-BCStandard mixture is 5.20% while AC-BCBottom Ash mixture is 5.25%. Bottom ash has higher porosity along with a little break field and has round shape so that the asphalt absorption is bigger than the crushed stone. Bottom ash can be used as an alternative aggregate to increase the value of flow of the AC-BC mixture, thus converting waste to valuable material.

  13. Durability of Modified Expanded Polystyrene Concrete after Dynamic Cyclic Loading

    Directory of Open Access Journals (Sweden)

    Wenbo Shi

    2016-01-01

    Full Text Available EPS concrete was produced by mixing the expanded polystyrene spheres (EPS and polymer emulsion and thickener to the matrix concrete, and this concrete had good vibration energy absorption characteristics. Based on the experimental data obtained on EPS volume ratio of 0%, 20%, 30%, and 40% by replacing matrix or coarse aggregate, the two design styles had nearly the same compressive strength. By applying frequency of 5 Hz, 50000 or 100000 times, 40 KN, 50 KN, and 60 KN cyclic loading, it is shown that the higher the inclusion size was, the lower the compressive strength of the EPS concrete would be; the larger the applying dynamic cyclic load was, the more obvious the compressive strength changing would be. Meanwhile, the strength of EPS concrete had no evident change after durability test. The results of this research had practical significance on using EPS concrete in some long-term cyclic dynamic load engineering.

  14. An Exploratory Compressive Strength Of Concrete Containing Modified Artificial Polyethylene Aggregate (MAPEA)

    Science.gov (United States)

    Hadipramana, J.; Mokhatar, S. N.; Samad, A. A. A.; Hakim, N. F. A.

    2016-11-01

    Concrete is widely used in the world as building and construction material. However, the constituent materials used in concrete are high cost when associated with the global economic recession. This exploratory aspires to have an alternative source of replacing natural aggregate with plastic wastes. An investigation of the Modified Artificial Polyethylene Aggregate (MAPEA) as natural aggregate replacement in concrete through an experimental work was conducted in this study. The MAPEA was created to improve the bonding ability of Artificial Polyethylene Aggregate (APEA) with the cement paste. The concrete was mixed with 3%, 6%, 9%, and 12% of APEA and MAPEA for 14 and 28 curing days, respectively. Furthermore, the compressive strength test was conducted to find out the optimum composition of MAPEA in concrete and compared to the APEA concrete. Besides, this study observed the influence and behaviour of MAPEA in concrete. Therefore, the Scanning Electron Microscopy was applied to observe the microstructure of MAPEA and APEA concrete. The results showed the use of high composition of an artificial aggregate resulted inferior strength on the concrete and 3% MAPEA in the concrete mix was highest compressive strength than other content. The modification of APEA (MAPEA) concrete increased its strength due to its surface roughness. However, the interfacial zone cracking was still found and decreased the strength of MAPEA concrete especially when it was age 28 days.

  15. Low temperature performance of polyphosphoric acid asphalt and polyphosphoric acid-SBS modified asphalt%多聚磷酸及多聚磷酸-SBS改性沥青低温性能

    Institute of Scientific and Technical Information of China (English)

    王岚; 王子豪; 李超

    2017-01-01

    Based on the bending bean rheometer test (BBR)and DSC measurement of the glass transition tempera-ture,the low temperature properties of asphalt with different dosage of poly phosphoric acid (PPA)and SBS-PPA were studied.The effect of PPA content on the performance of asphalt at low temperature was analyzed using the method of single factor variance.The phase structure characteristics of SBS-PPA composite modified asphalt were observed and analyzed by fluorescence microscope.The results shows that PPA addition can improve the low temperature performance of matrix asphalt and SBS modified asphalt,and with the increase of PPA content,low temperature anti-crack performance of bitumen is better.But with the decrease of temperature,the effect of low temperature improvement is gradually reduced.Effect degree of PPA on the properties of base asphalt at low temperature is different at different temperature.At the temperature of -1 8 -1 2 ℃,PPA has significant effects on the low temperature performance of base asphalt.At the temperature of -30 -24 ℃,PPA has no significant impact on the low temperature performance of base asphalt.While the effect of PPA on the low temperature performance of SBS-PPA modified asphalt at different temperatures is not significant.The low temperature anti-crack performance of SBS-PPA modified bitumen is better than that of PPA modified asphalt,and the addition of PPA can effectively promote the SBS to disperse into small particles and become more uniform distribution in the asphalt,so the storage stability and the space mesh structure of SBS modified asphalt can be improved effectively.%基于弯曲流变试验(BBR)并结合DSC试验测得的玻璃化转移温度,对不同掺量的多聚磷酸(PPA)改性沥青和乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)-PPA 复合改性沥青的低温性能进行了研究。用单因素方差法分析了不同温度下,PPA掺量对沥青低温性能的影响。利用荧光显微镜观察并分析了 SBS

  16. 温拌沥青混凝土技术在阿赛公路改建工程中的应用%Application of Warm Mix Asphalt Concrete Technology in Athy Road Renovation Project

    Institute of Scientific and Technical Information of China (English)

    黄世静; 陈旭茜

    2014-01-01

    In China's highway construction and maintenance ,hot mix asphalt dosage of up to several mil‐lion tons per year .T he use of hot mix asphalt in the construction large-scale is not only need to consume a lot of energy ,and emit large amounts of gas and dust .On the increasingly high demand for energy and environ‐mental protection premise ,many domestic and foreign research scholars believe that reduce the temperature of the asphalt mix in the production process is an effective way to improve and solve this problem .In this article , starting from the construction application combined with Athy road Rebuilding of Grade Two Highways Duofu‐tun to Saierlong section ,the top layer of surface-active type using warm mix asphalt ,discusses and research their production mix ,paving and site construction technology ,and conducted a warm mix asphalt performance detection .The results show that :the surfactant warm mix asphalt type volume index ,asphalt content ,aggre‐gate gradation requirements are met .At the same time ,a significant reduction in the production mix at the same temperature ,to a certain extent ,improve the efficiency of production of asphalt mixture .To promote the use of warm mix asphalt concrete in highway engineering has accumulated rich experience .%本文从施工应用出发,结合阿赛公路多福屯至赛尔龙段二级公路改建工程上面层采用表面活性型温拌沥青混合料的实际,对其生产配合比、现场铺筑的施工工艺及温拌混合料路用性的检测进行了论述。结果表明:表面活性型温拌沥青混合料体积指标、沥青用量、矿料级配均满足要求。其大幅度降低混合料生产温度的同时,在一定程度上也提高了沥青混合料的生产效率,为温拌沥青混凝土在公路工程中的推广应用积累了丰富的经验。

  17. prediction of concrete mix cost using modified regression theory

    African Journals Online (AJOL)

    Kambula

    2013-07-02

    Jul 2, 2013 ... The concrete cost analysis is based on the current market prices of concrete constituent materials. A Price Fluctuation Factor (PFF) can be used to take care of ... techniques to fit empirical models to the data for each ...

  18. 论改性沥青在路面工程中的应用%Application of Modifying Asphalt in Road Surface Project

    Institute of Scientific and Technical Information of China (English)

    穆艳林

    2009-01-01

    文章介绍了改性沥青在我国公路交通建设中的发展情况,从改性沥青的概念、铺筑路面的优点、类型、经济效益及发展前景和存在的问题,改性设备的需求和研究方向进行了论述.%This paper briefed the modifying asphalt in our country highway traffic construction state, from modifying asphalt's concept, the road surface the merit, the type, economic efficiency and prospects for development and existence question, the modified equipment's demand and the research direction have carried on the elaboration.

  19. Structural Design and Mechanical Analysis of Full-Depth High Modulus Asphalt Concrete Pavement%全厚式高模量沥青混凝土路面结构设计及力学分析

    Institute of Scientific and Technical Information of China (English)

    李涛; 刘宁; 张涛

    2013-01-01

    The pavement special program PADS is used to calculate the three kinds of asphalt concrete pavement structure thickness which are full-depth high modulus, full-depth ordinary and semi-rigid base asphalt concrete pavement, respectively. The 3-D element model of asphalt concrete pavement structure is built based on the elastic mechanics to evaluate the design bottom stress state under loads. The rutting of the three kinds of pavement is determined by using asphalt concrete pavement permanent deformation prediction method in MEPDG of the United States. Also, their fatigue life is calculated. The results show that the full-depth high modulus asphalt concrete pavement structure is able to effectively decrease the thickness of the pavement structure, at the same time exhibits the best overall performance in rutting resistance and fatigue properties.%利用路面专用程序PADS计算全厚式高模量、全厚式普通和半刚性基层3种沥青混凝土路面结构厚度;根据弹性层状理论体系,建立了上述3种沥青混凝土路面结构三维有限元模型,对路面结构在荷载作用下的设计层层底应力状态进行对比分析;应用美国MEPDG推荐的沥青混凝土路面永久变形预估方法对沥青混凝土路面结构进行车辙预估,并对其疲劳寿命进行了计算.结果表明,全厚式高模量沥青混凝土路面结构能够有效减薄路面结构厚度,是抗车辙性能及疲劳性能综合最优的路面结构类型.

  20. 沥青混凝土心墙坝水力劈裂发生机理及分析%Mechanism and analysis of occurrence of hydraulic fracturing for asphalt concrete core dam

    Institute of Scientific and Technical Information of China (English)

    邓建伟; 凤炜; 何建新

    2014-01-01

    The influence of hydraulic fracturing problem of soil core wall dam on the safety of embank-ment dam has been paid great attention in engineering field.This paper analyzed the mechanism that hy-draulic fracturing occurs in asphalt concrete core wall, and proposed that the horizontal seam produced in construction of compacted core wall's caused by “pine cone effect” and the low permeability of asphalt concrete are the important material conditions of hydraulic fracturing, while the“arch effect” and power-ful “water wedge effect” produced by transition material and core wall interactions are the hydraulic frac-ture mechanics conditions.The analysis of examples proved that the soil core wall and the asphalt con-crete core wall all exist the risk of hydraulic fracturing,which need to pay close attention in the field of water conservancy sector.It noted that high asphalt concrete core wall dam should be carefully studied and the core wall's impervious safety and reliability be evaluated.The result has a certain reference value for the design and construction of asphalt concrete core wall dam.%土质心墙坝的水力劈裂问题对土石坝安全的影响已引起工程界的高度重视。本文分析了沥青混凝土心墙发生水力劈裂的机理,提出心墙碾压施工“松塔效应”产生的水平缝和沥青混凝土的低透水性是发生水力劈裂的重要物质条件,而过渡料与心墙相互作用产生的“拱效应”及强大的“水楔”作用是发生水力劈裂的力学条件。通过实例分析证明沥青混凝土防渗心墙与土质心墙一样也存在水力劈裂的风险,需引起水利界的高度重视,对于高沥青混凝土心墙坝应审慎研究并评价心墙的防渗安全可靠性。分析结果对沥青混凝土心墙坝的设计与施工有一定参考意义。

  1. A comparison of flexural strengths of polymer (SBR and PVA modified, roller compacted concrete

    Directory of Open Access Journals (Sweden)

    John N. Karadelis

    2015-09-01

    Full Text Available This brief article aims to reveal the flexural performance, including the equivalent flexural strength of PVA (Polyvinyl Alcohol modified concrete by comparing it primarily with that of SBR (Styrene Butadiene Rubber concrete. This data article is directly related to Karadelis and Lin [6].

  2. A comparison of flexural strengths of polymer (SBR and PVA) modified, roller compacted concrete.

    Science.gov (United States)

    Karadelis, John N; Lin, Yougui

    2015-09-01

    This brief article aims to reveal the flexural performance, including the equivalent flexural strength of PVA (Polyvinyl Alcohol) modified concrete by comparing it primarily with that of SBR (Styrene Butadiene Rubber) concrete. This data article is directly related to Karadelis and Lin [6].

  3. A comparison of flexural strengths of polymer (SBR and PVA) modified, roller compacted concrete

    OpenAIRE

    Karadelis, John N.; Lin, Yougui

    2015-01-01

    This brief article aims to reveal the flexural performance, including the equivalent flexural strength of PVA (Polyvinyl Alcohol) modified concrete by comparing it primarily with that of SBR (Styrene Butadiene Rubber) concrete. This data article is directly related to Karadelis and Lin [6].

  4. The Compression-deformation Behaviour of Concrete with Various Modified Recycled Aggregates

    Institute of Scientific and Technical Information of China (English)

    DU Ting; LI Huiqiang; WU Xianguo; QIN Yawei

    2005-01-01

    Modified recycled aggregates were prepared with three different cement-admixture grouts. The physical properties, such as water absorption, apparent density, crushing index, slump and compressive strength of the recycled aggregate and the recycled concretes were tested, and the tests for the compression-deformation behavior of the concretes were also performed. The experimental results show that the cement-Kim powder grout is satisfied for enhancing the recycled concrete, and the modification of the recycled aggregate with the grouts can improve the toughness and the deformation ability of the concretes.

  5. Research on Influencing Factors for Compaction Performance of Asphalt Concrete Pavement%沥青混凝土路面压实性能影响因素分析

    Institute of Scientific and Technical Information of China (English)

    韩树峰

    2013-01-01

    The compaction quality of an asphalt concrete pavement has a pivotal role on the long-term performance of the pavement. Focusing on the main influencing factors such as the material composition of asphalt mixture, pavement structure, natural environment conditions, compaction machinery and so on, the impact mode and impact extent on the compaction performance of asphalt pavement are explored and discussed here in detail. The research results could provide some references for the design of asphalt pavement materials, structure and construction.%沥青混凝土路面的压实质量对路面的长期性能具有举足轻重的作用.重点从沥青混合料的组成材料因素、路面结构、自然环境条件、压实机械设备等方面探讨其对沥青路面压实性能的影响方式和影响程度.研究成果可为沥青路面材料和结构设计及施工等方面提供一定的参考价值.

  6. THE FORMATION OF THE MODIFIED CONCRETE STRUCTURE FOR PIPE COLLECTORS

    Directory of Open Access Journals (Sweden)

    V. M. Pylypenko

    2009-03-01

    Full Text Available In the article main points of developed technology of vibroimpact-pulse compaction of concrete mix for producing the pipes of sewage collectors are stated. It is shown that using the offered technology ensures the intensive growth of concrete strength at an initial period of hardening, the reduction of duration of heat treatment or its absolute avoidance, the manufacture of products with the stability and longevity of structures.

  7. Preparation and Performance of PAN-based Carbon Fiber Conductive Asphalt Concrete%PAN基碳纤维导电沥青混凝土的制备及性能

    Institute of Scientific and Technical Information of China (English)

    冯新军; 查旭东; 程景

    2012-01-01

    In order to prepare conductive asphalt concrete for melting ice and snow on road surface,preparation and performance of PAN-based carbon fiber conductive asphalt concrete were studied.Through resistivity test of Marshall specimen,chopped length of PAN-based carbon fiber was determined.After the mixing test and Marshall compaction test of asphalt mixture,mixing techniques of PAN-based carbon fiber conductive asphalt concrete was put forward.The optimal oil-stone rate of PAN-based carbon fiber conductive asphalt concrete was determined with Marshall test design method,and the technical standards were adjusted according to their structural characteristics.Through tests of resistivity,rutting,trabecular bending,immersion Marshall and freezing-thawing splitting,variation laws of conductive properties and pavement performance with PAN-based carbon fiber quality fraction of conductive asphalt concrete were analyzed.The results show that conductive asphalt concrete with 0.1% PAN-based carbon fiber quality fraction has excellent conductive properties and pavement performance.%为制备能够融冰化雪的导电沥青混凝土,对聚丙烯腈(PAN)基碳纤维导电沥青混凝土的制备及性能进行了研究。通过沥青混合料马歇尔试件的电阻率测试试验,确定了碳纤维的短切长度。通过沥青混合料拌和试验和马歇尔击实试验,提出了导电沥青混合料的拌和工艺。采用马歇尔试验配合比设计方法,根据导电沥青混合料的结构特征调整了技术标准,确定了导电沥青混合料的最佳油石比。通过电阻率试验、车辙试验、小梁低温弯曲试验、浸水马歇尔试验和冻融劈裂试验,分析了导电沥青混合料的导电性能和路用性能随碳纤维掺量的变化规律。结果表明:当PAN基碳纤维掺量(质量分数)取0.1%时,导电沥青混凝土既可以获得优良的导电性能,也可以获得优良的路用性能。

  8. Composite Concrete Modifier CM 02-10 and Its Impact on the Strength Characteristics of Concrete

    Directory of Open Access Journals (Sweden)

    Akimov Luka

    2016-01-01

    Full Text Available The main aim of this research is the investigation of effect of the composite additive (a mixture of hyperplasticizer and microsilica CM 02-10 (10 % of MS and 0.2 % of HP on strength characteristics of concrete. Interaction of concrete with plasticizing and siliceous additives individually depending on their percentage content by the weight of cement is also investigated. Results of experiments with such additives on the fluidity of concrete mix and strength of concrete are presented. Additives used in the experiment: superplasticizer S-3, fused microsilica FMS-85, hyperplasticizer PENTAFLOW AC 2, and composite additive CM 02-10. In this paper results of tests of samples aged 3, 7 and 28 days are presented.

  9. Improving Asphalt Mixtures Performance by Mitigating Oxidation Using Anti-Oxidants Additives

    Science.gov (United States)

    Dessouky, Samer; Diaz, Manuel

    Polymer modified additives are typically used to improve rheological properties of asphalt binder as well as mechanical properties of asphalt concrete mix. In this study, polymer-modified binder PG70-22 is mixing with two co-polymers enhanced with anti-oxidant agents namely; Solution Styrene-Butadiene Rubber (SSBR) and Solution Ethylene-Butylene/Styrene (SEBS). The objective of this study is to characterize the effect of those additives into the rheological properties of the asphalt binder using temperature sweep test and mechanical properties of asphalt mixes. The aging index is determined to evaluate the role of additives to reduce brittleness after aging of the binder. The performance of asphalt mixes were characterized by Hamburg Wheel Tracking Test for moisture damage, Beam Fatigue Test for fatigue properties and Flow Number Test for rutting performance. It is found that the asphalt mixes with enhanced binders are improving its rutting and moisture resistance but decreased its fatigue life compared to the control mix.

  10. Research on Performance of Asphalt Modified by Polyethylene Made from Recycled Plastics%废旧塑料合成MPE颗粒对沥青改性效果的试验研究

    Institute of Scientific and Technical Information of China (English)

    王家主

    2011-01-01

    Granular modified polyethylene made from recycled plastics and tackifier can be added to asphalt mix plant to modify asphalt, which avoids the process of modifying asphalt in the factory. Two virgin asphalts, with their four components content tested, are chosen to study the MPE modified asphalt. Asphalts with different quantities of MPE are prepared by high speed shearing machine. And asphalt performance of every sample is tested, which varied with different MPE content, meanwhile, curves of performance versus MPE content are drawn. Last, all the test results and analysis indicate that MPE can obviously improve asphalt performances such as high temperature performance, aging resistance and anti-stripping. However, there is an optimal MPE content which is 6% of asphalt mass.%采用废旧塑料和增黏剂合成的MPE颗粒,可在道路沥青混合料拌和时直接投入,起到对道路沥青改性的作用,省去了在加工厂制备生产改性沥青的过程.为研究MPE对沥青的改性作用,选取两种基质沥青,测定其四组分含量,通过高速剪切设备制备不同MPE掺量的改性沥青,分别对其进行沥青性能的检测,绘制各项沥青性能随MPE掺量的变化曲线.试验结果表明,MPE对沥青的高温、老化和水稳定性能具有明显的改善作用,同时MPE存在一个最佳掺量,约为沥青质量的6%.

  11. Influence of association of "EVA-NBR" on indirect tensile strength of modified bituminous concrete

    Science.gov (United States)

    Chinoun, M.; Soudani, K.; Haddadi, S.

    2016-04-01

    The aim of this work is to contribute to the improvement of the mechanical properties of bituminous concrete by modification of bituminous concrete. In this study, we present the results of the indirect tensile strength "ITS" of modified bituminous concrete by the combination of two modifiers, one is a plastomer EVA (Ethylene Vinyl Acetate) and the other is a industrial waste from the shoe soles grinding NBR (Nitrile Butadiene Rubber) as crumb rubber. To modify the bitumen a wet process was used. The results show that the modification of bitumen by EVA-NBR combination increases their resistance to the indirect traction "ITS" compared to the bituminous concrete control. The mixture of 5% [50% EVA+ 50% NBR] is given the best result among the other associations.

  12. Evaluation on Low Temperature Performance of Recycled Asphalt Mixture Using Warm Mix Asphalt Technology

    Directory of Open Access Journals (Sweden)

    Xiaolan Duan,

    2015-04-01

    Full Text Available In this paper, the basic idea is about the recycled technology of asphalt mixture, more in-depth study of the lowtemperature performance of warm mix asphalt(WMA.First of all, Including the evaluation of low temperature performance of WMA made of reclaimed asphalt pavement (RAP (passed and not passed 2.36mm screen, and the influence of WMA with RAP mixed of different dosage of dispersant. Then, using the SBS modified asphalt and base asphalt were test at low temperature, research on the influence of different type of asphalt to the low temperature performance of WMA.

  13. Explore the Damage Problems and Effective Protection Measures of Highway Asphalt Concrete Pavement%探究高速公路沥青混凝土路面破损问题及有效防护措施

    Institute of Scientific and Technical Information of China (English)

    何娅兰

    2014-01-01

    高速公路是我国重要的交通设施,对我国的经济发展具有极大影响。本文列举了高速公路沥青混凝土路面破损的几种类型,并对沥青路面破损的原因和防护措施进行了分析。%Highway is Chinese important traffic facilities, which has a great influence on the economic development of China. This paper enumerates several types of highway asphalt concrete pavement damage and carries on the analysis of the causes and protective measures of the asphalt pavement da-mage.

  14. Corrosion of Modified Concrete with Sugar Cane Bagasse Ash

    Directory of Open Access Journals (Sweden)

    R. E. Núñez-Jaquez

    2012-01-01

    Full Text Available Concrete is a porous material and the ingress of water, oxygen, and aggressive ions, such as chlorides, can cause the passive layer on reinforced steel to break down. Additives, such as fly ash, microsilica, rice husk ash, and cane sugar bagasse ash, have a size breakdown that allows the reduction of concrete pore size and, consequently, may reduce the corrosion process. The objective of this work is to determine the corrosion rate of steel in reinforced concrete by the addition of 20% sugar cane bagasse ash by weight of cement. Six prismatic specimens (7×7×10 cm with an embedded steel rod were prepared. Three contained 20% sugar cane bagasse ash by weight of cement and the other three did not. All specimens were placed in a 3.5% NaCl solution and the corrosion rate was determined using polarization resistance. The results showed that reinforced concrete containing sugar cane bagasse ash has the lowest corrosion rates in comparison to reinforced concrete without the additive.

  15. Study on Applicability of Natural Gravel Aggregate in Asphalt Concrete Core Wall of Wuyi Reservoir%五一水库天然砾石骨料在沥青混凝土心墙中的适用性研究

    Institute of Scientific and Technical Information of China (English)

    王文政; 唐新军; 何建新; 张涛; 朱西超

    2014-01-01

    Taking the asphalt concrete core wall of Wuyi reservoir sand gravel dam as research object ,the adhesion ex-periment between natural aggregate and asphalt ,mixture ratio designing of natural gravel aggregate ,asphalt and concrete , compression test ,penetration test ,trabecular bending test as well as water stability test were conducted .Then the results were compared with the related data of alkaline dolomite aggregate asphalt concrete .The result suggest that cement ,as filler and the improvement medium ,can significantly improve the adhesion between natural gravel aggregate and asphalt . On this account ,the natural gravel aggregate asphalt concrete can meet the requirements of design specifications ,and it is almost as good as alkaline dolomite aggregate asphalt concrete .%以新疆五一水库砂砾石坝沥青混凝土心墙为例,进行了天然砾石骨料与沥青的黏附性试验、天然砾石骨料沥青混凝土配合比试验以及压缩试验、渗透试验、小梁弯曲试验、水稳定性试验,并与碱性白云岩骨料沥青混凝土相关性能进行对比。结果表明,以水泥作为填料又兼做提高沥青与骨料黏附力的措施,可明显改善天然砾石骨料与沥青胶浆的黏附性,使天然砾石骨料沥青混凝土各项性能指标满足规范要求,且近似达到碱性白云岩骨料沥青混凝土的性能。

  16. HIGHLY EFFECTIVE CHEMICAL MODIFIERS FOR PRODUCTION OF CONCRETES WITH PRE-SET PROPERTIES

    Directory of Open Access Journals (Sweden)

    Tkach Evgeniya Vladimirovna

    2012-10-01

    Full Text Available The paper demonstrates the application of industrial by-products and recycled materials. Waterproofing admixtures improve the structure and the properties of the cement stone. Development and preparation of highly effective waterproofing modifiers of durable effect, as well as development of the process procedure parameters, including mixing, activation, heat treatment, etc. are to be implemented. The composition of waterproofing modifiers is to be fine-tuned to synergize the behaviour of various ingredients of cement systems to assure the substantial improvement of their strength, freeze- and corrosion resistance. Multi-functional waterproofing admixtures were used to produce highly effective modified concretes. The key idea of the new method of modifying cement-based building materials is that the waterproofing admixture concentration is to exceed 10% of the weight of the binding agent within the per-unit weight of the cement stone, given that its strength does not deteriorate. GKM-type modifier coupled with organo-mineral waterproofing admixture concentration agent GT-M may be recommended for mass use in the manufacturing of hydraulic concrete and reinforced concrete products. Overview of their practical implementation has proven that waterproofing modifier GKM-S, if coupled with waterproofing admixture concentration agent GT-M, improves the corrosion control inside the cement stone and makes it possible to manufacture durable concrete and reinforced concrete products that demonstrate pre-set physical and processing behaviour. Comprehensive concrete modification by modifier GKM-S and waterproofing admixture concentration agent GT-M may be regarded as one of the most ambitious methods of production of highly effective waterproof concretes.

  17. 有机蒙脱土/废胶粉复合改性沥青的性能%Properties of Organic Montmorillonite/Crumb Rubber Compound Modified Asphalt

    Institute of Scientific and Technical Information of China (English)

    肖新颜; 杨泽清

    2013-01-01

    Organic montmorillonite (OMMT)/crumb rubber compound modified asphalt was prepared via melt blending,and the microstructure of the product was characterized and analyzed by means of XRD and AFM.Moreover,the physical properties,thermal oxidative aging properties and thermal storage stability of the product were investigated.The results show that (1) the dispersion of crumb rubber in the modified asphalt becomes more uniform and an exfoliated structure forms due to the doping of OMMT; (2) as compared with the crumb rubber modified asphalt,OMMT/crumb rubber compound modified asphalt is of improved high-temperature performances,for instance,with the increase of OMMT dosage,the softening point sharply increases,and the penetration (25 ℃) and the ductility (5 ℃) both decrease ; and (3) after the doping of OMMT,both the thermal oxidative aging properties and the thermal storage stability of the compound modified asphalt improve significantly.%采用熔融共混法制备了有机蒙脱土(OMMT)/废胶粉复合改性沥青,通过X射线衍射(XRD)分析和原子力显微镜(AFM)分析表征了复合改性沥青的微观结构,研究了复合改性沥青的物理性能、抗热氧老化性能和热储存稳定性.结果表明:OMMT的掺入使废胶粉在沥青中的分散更加均匀,OMMT/废胶粉复合改性沥青形成剥离结构;与废胶粉改性沥青相比,OMMT/废胶粉复合改性沥青的高温性能得到改善,随着OMMT掺量的增加,软化点大幅升高,25℃针入度及5℃延度减小;与废胶粉改性沥青相比,OMMT/废胶粉复合改性沥青的抗热氧老化性能和热储存稳定性明显提高.

  18. Evaluation of bitumen-rubber asphalt manufactured from modified binder at lower viscosity

    CSIR Research Space (South Africa)

    O'Connell, Johannes S

    2010-08-01

    Full Text Available In South Africa, crumb tyre-modified bitumen commnly known as bitumen-rubber binder has viscosity limits specified by the current edition of TG1: The Use of Modified Bituminous Binders in Road Construction. As the crumb rubber is 'digested...

  19. 黄金坪深覆盖层上沥青混凝土心墙堆石坝数值分析%Numerical analysis for Huangjinping Rockfill Dam with asphalt concrete core construed on deep overburden

    Institute of Scientific and Technical Information of China (English)

    林道通; 朱晟; 稽红刚; 伍小玉

    2011-01-01

    By means of 3-D non-linear finite element methods, the stresses and deformations of Huangjinping Roelcfill Dam with asphalt concrete core constructed on deep overburden were calculated and analyzed. Some conclusions are drawn as follows: the stresses and deformations of Huangjinping Rockfill Dam during the completion and impoundment periods are within the allowable range of the Chinese codes. The distribution rules of the displacement are reasonable. Hydraulic fracture and shear failure will not occur in the core wall. The deformation between the asphalt concrete core wall and the bed of concrete is small. The structural design of Huangjinping Rockfill Dam is rational.%采用三维非线性有限元数值分析方法对坐落于深覆盖层上的黄金坪沥青混凝土心墙坝进行应力变形计算,结果表明:在竣工期和满蓄期大坝的应力与变形都在规范允许范围内;位移分布规律基本合理;心墙不会发生水力劈裂,没有发生剪切破坏;沥青混凝土心墙与河床中央混凝土廊道和混凝土基座之间的错动变形较小;大坝结构设计是合理的.

  20. Evaluation of the Permanent Deformations and Aging Conditions of Batu Pahat Soft Clay-Modified Asphalt Mixture by Using a Dynamic Creep Test

    Directory of Open Access Journals (Sweden)

    Al Allam A. M.

    2016-01-01

    Full Text Available This study aimed to evaluate the permanent deformation and aging conditions of BatuPahat soft clay–modified asphalt mixture, also called BatuPahat soft clay (BPSC particles; these particles are used in powder form as an additive to hot-mix asphalt mixture. In this experiment, five percentage compositions of BPSC (0%, 2%, 4%, 6%, and 8% by weight of bitumen were used. A novel design was established to modify the hot-mix asphalt by using the Superpave method for each additive ratio. Several laboratory tests evaluating different properties, such as indirect tensile strength, resilient stiffness modulus, and dynamic creep, was conducted to assess the performance of the samples mixed through the Superpave method. In the resilient modulus test, fatigue and rutting resistance were reduced by the BPSC particles. The added BPSC particles increased the indirect tensile strength. Among the mixtures, 4% BPSC particles yielded the highest performance. In the dynamic creep test, 4% BPSC particles added to the unaged and short-term aged specimens also showed the highest performance. Based on these results, our conclusion is that the BPSC particles can alleviate the permanent deformation (rutting of roads.

  1. 信息动态%A Research on the Pavement Performance of Warm Mix Buton Mastic Asphalt

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Compositing modified asphalt mixture is a kind of asphalt mixture which uses Buton Mastic Asphalt(BMA) and warm modifier compound modification. It is proved that the composite modified asphalt mixture technology can greatly reduce the mixing temperature, save energy and protect the environment, and can guarantee good road performance. Employing Buton Mastic Asphalt as modifier can obviously increase the high temperature stability of asphalt mixture, with little impact on low temperature performance.

  2. Performance of skid resistance of warm-mix asphalt with buton natural asphalt-rubber (BNA-R) and zeolite additives as a result of road surface temperature changes

    Science.gov (United States)

    Anagi, Natasha; Hadiwardoyo, Sigit Pranowo; Sumabrata, R. Jachrizal; Wahjuningsih, Nurul

    2017-06-01

    Roughness of the road surface acts as an obstacle for the vehicle wheel slip on the road surface especially in wet conditions. Road surface roughness can be generated from the properties of the aggregate or bitumen as a characteristic of asphalt mixture. Various types of added material have been used to improve the performance of hot mix asphalt mixture as well as the warm mix asphalt. The addition of BNA-R and zeolite on the warm asphalt mixtures has been investigated, particularly related with its effect on the value of the skid surface due to the wheels track of the vehicle. The study was conducted in an asphalt mixture before and after the traversed wheel condition. In this study, 7.560 trajectory path using the Wheel Tracking Machine and skid resistance test using a modified British Pendulum Tester, were conducted. Skid resistance test involved various temperatures on the surface of the specimen. The results showed that the addition of BNA-R can increase the value of the skid at the beginning of the track, but at the last track, skid resistance performance was stagnant. Zeolite additive material in warm mix asphalt has improved skid resistance, especially the resistance of asphalt concrete mixture to temperature changes.

  3. 基于流变学的RA改性沥青性能研究%Study on properties of RA modified asphalt based on rheology

    Institute of Scientific and Technical Information of China (English)

    刘黎萍; 王明

    2014-01-01

    将沥青组分(RA)从印度尼西亚布敦岩沥青(简称为 BRA)中抽提出来,作为基质沥青的改性剂。选取3个不同的掺配比例(10%,15%和20%),制备 RA改性沥青。采用 SHRP 试验,对改性沥青的高温性能、低温性能及粘温性能进行研究。分析结果表明:BRA 中的沥青组分是一种良好的天然改性剂。随着其掺量的增加,基质沥青的抗车辙因子和高温粘度均有所提高,高温性能和粘温性能均得到显著改善;低温时,蠕变劲度增大,蠕变劲度变化率变小,低温性能有所下降。因此,工程实际应用时,应兼顾沥青的高、低温及粘温性能,建议以基质沥青为基数,沥青组分的掺配比例不宜超过15%。%RA was extracted out from the BRA as the asphalt modifier.Three different blending proportion(10%,15%和 20%)are selected for the preparation of RA modified asphalt.SHRP test is used to study high-temperature properties,low temperature per-formance,viscosity-temperature properties of these modified asphalts.The results show that:RA bitumen component is a good natural modifiers,with the increase of its con-tent,the asphalt rutting factor,high temperature viscosity increase significantly and high-temperature performance and viscosity-temperature properties are improved,low creep stiffness increases,low temperature performance decreases.Therefore,during the practical application of engineering,both high pitch,low-temperature and viscosity-tem-perature performance should be considered,it is proposed that base asphalt as the base, the proportion of bitumen blending component should not exceed 15%.

  4. Influence of Crumb-Rubber in the Mechanical Response of Modified Portland Cement Concrete

    OpenAIRE

    Retama, J.; Ayala, A. G.

    2017-01-01

    The influence of crumb-rubber on the mechanical properties of Portland cement concrete (PCC) is studied by experimental tests and numerical simulations. The main hypothesis of the study is that replacing part of the stone aggregate with crumb-rubber in the mix modifies the energy dissipation during the cracking process and affects the concrete behaviour under monotonically increasing loads. The experimental research program characterizes the mechanical properties of PCC for three different ty...

  5. Tensile Bond Strength of Latex-Modified Bonded Concrete Overlays

    Science.gov (United States)

    Dubois, Cameron; Ramseyer, Chris

    2010-10-01

    The tensile bond strength of bonded concrete overlays was tested using the in-situ pull-off method described in ASTM C 1583 with the goal of determining whether adding latex to the mix design increases bond strength. One slab of ductile concrete (f'c > 12,000 psi) was cast with one half tined, i.e. roughened, and one half steel-troweled, i.e. smooth. The slab surface was sectioned off and overlay mixtures containing different latex contents cast in each section. Partial cores were drilled perpendicular to the surface through the overlay into the substrate. A tensile loading device applied a direct tensile load to each specimen and the load was increased until failure occurred. The tensile bond strength was then calculated for comparison between the specimens.

  6. Effects of an AMPS-modifi ed Polyacrylic Acid Superplasticizer on the Performance of Concrete Materials

    Institute of Scientific and Technical Information of China (English)

    CHEN Baofan

    2015-01-01

    A self-made 2-acrylamide-2-methyl propylene sulfonic (AMPS)-modified polyacrylic acid superplasticizer and two other commercially available superplasticizers with different molecular structures are used in this study to investigate the effect of an AMPS-modifi ed polyacrylic acid superplasticizer on the properties of concrete materials. In the experiments, initial and 1.5 h slumps over time after admixtion are determined by adding different dosages of three superplasticizers into the premixed concrete to characterize the slump loss resistance of the premixed concrete. The water-reducing rates of three different types of concrete are determined to characterize the water-reducing capacity of the concrete with each superplasticizer. The 3, 7 and 28 d compressive strength is determined to characterize the mechanical properties of the concrete with each superplasticizer. In the meanwhile, 1, 1.5 and 2.0 h slump loss rates over time after admixtion are determined by adding different dosages of the three superplasticizers into the high-performance concrete (HPC) to characterize the slump loss resistance of HPC. The 7, 28, 60 and 90 d compressive strength is determined to characterize the compressive properties of HPC with each superplasticizer. The dry shrinkage rates of three different types of HPC are determined with each superplasticizer. Electricfl ux after standard curing for 56 d and chloride ion diffusion coeffi cient after curing for 28 d of HPC are determined to characterize the impermeability of HPC with each superplasticizer. The cross-section was examined using a scanning electron microscopy (SEM) system. Results demonstrate that the AMPS-modifi ed polyacrylic acid superplasticizer has better water-reducing effect and slump than the two commercially available polyacrylic acid superplasticizers. The AMPS-modifi ed polyacrylic acid superplasticizer also shows signifi cant improvement of the compressive strength, especially in comprehensive performance of HPC. In

  7. Influence Factors Research on Performance of SBR Modified Emulsion Asphalt%SBR 改性乳化沥青路用性能影响因素研究

    Institute of Scientific and Technical Information of China (English)

    陈益平

    2014-01-01

    为了研究基质沥青、SBR改性剂、乳化剂等原材料对SBR改性乳化沥青性能的影响,对不同基质沥青及不同SBR改性剂和乳化剂掺量下的SBR改性乳化沥青路用性能进行分析。结果表明:SBR胶乳掺量的增加使改性乳化沥青蒸发残留物低温性能和高温性能增强;乳化剂对改性乳化沥青储存稳定性有显著影响。%In order to study the impact of matrix asphalt , SBR latex , emulsifiers and other raw materials on the performance of modified e-mulsified asphalt , the emulsified asphalt performance of different matrix asphalt , latex and emulsifier dosages was analyzed .The results show that the increasing of dosage of SBR latex increased the cryogenic property and elevated temperature property of evaporated modified e -mulsified asphalt residue;and emulsifier has a significant effect on the storage stability of modified emulsified asphalt .

  8. Development of asphalts and pavements using recycled tire rubber. Phase 1, Technical feasibility. Technical progress report, September 1, 1994--August 31, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Bullin, J.A.; Davison, R.R.; Glover, C.J. [and others

    1996-06-01

    About 285 million tires are discarded every year; less than 100 million are currently being recycled, with the rest being placed in landfills and other waste sites. A solution to reduce the littering of the environment is to use ground tire rubber in road construction. Currently, about 27 million tons of asphalt are used each year in road construction and maintenance of the country`s 2 million miles of roads. If all of the waste tire rubber could be combined with asphalt in road construction, it would displace less than 6% of the total asphalt used each year, yet could save about 60 trillion Btus annually. Purpose of this project is to provide data needed to optimize the performance of rubber-asphalt concretes. The first phase is to develop asphalts and recycling agents tailored for compatibility with ground tire rubber. Chapter 2 presents results on Laboratory Testing and Evaluation: fractionate asphalt material, reblending for aromatic asphalts, verifying optimal curing parameters, aging of blends, and measuring ductilities of asphalt-rubber binders. Chapter 3 focuses on Evaluating Mixture Characteristics (modified binders). Chapter 4 covers Adhesion Test Development (water susceptibility is also covered). The final chapter focuses on the Performance/Economic Update and Commercialization Plan.

  9. Use of Recycling Building Demolition waste As Coarse Aggregate in Hot Mix Asphalt

    Directory of Open Access Journals (Sweden)

    Nabil I. Al- Sarrag* Hanaa Khaleel A Suham E. Saleh Al-Maliky

    2014-04-01

    Full Text Available At the recent years in Iraq, building demolition increase because of wars and the processes of destruction that lead to increase concrete waste, causing extreme pressure on the available land-filled sites that’s becomes a new challenge to local environment, in addition to south region from country poor from aggregate source.  So this study make as first evaluation to return use concrete aggregate for old and demolition building in concrete asphalt mix, the concrete aggregate obtained from building to live long more than 20 years after crash reinforcement concrete and sieving to get requirement granular particle to make locally asphalt mixture (Type IIIB depends on modified specification of State Commission of Roads and Bridges (2003 with percent (0,25,50,75,100% from weight of coarse aggregate.  Asphalt mixtures were tested by Marshall test, Indirect tensile strength test, and the loss of stability test.

  10. The Concrete and Pavement Challenge

    Science.gov (United States)

    Roman, Harry T.

    2012-01-01

    The modern world is characterized by the extensive use of concrete and asphalt pavement. Periodically, these materials are replaced and the old materials disposed of. In this challenge, students will be asked to develop ways to reuse the old materials. It is important for students to understand how concrete and asphalt are made and applied, as…

  11. The Concrete and Pavement Challenge

    Science.gov (United States)

    Roman, Harry T.

    2012-01-01

    The modern world is characterized by the extensive use of concrete and asphalt pavement. Periodically, these materials are replaced and the old materials disposed of. In this challenge, students will be asked to develop ways to reuse the old materials. It is important for students to understand how concrete and asphalt are made and applied, as…

  12. 纳米材料改性沥青路用结合料的性能%Performance of Nanomaterial Modified Asphalt as Paving Materials

    Institute of Scientific and Technical Information of China (English)

    孙璐; 辛宪涛; 王鸿遥; 顾文钧

    2012-01-01

    The anomaterial organobentonite, nano-SiO2 and SBS at different dimensions and scales were used to modify base asphalt material. The processing methods of modified asphalt were applied according to the structural properties of different modifier. The general performance and unconventional performance indicators were used to assess the performance of modification. The general indicators contain penetration, softening point, ductility and brookfield viscosity as well. The unconventional indicators contain rutting factor, zero shear viscosity and flexural creep stiffness as well. The results show that the nanomaterial as modifiers can improve significantly the performance of asphalt binder as paving materials.%选择不同形状和尺寸的纳米有机膨润土、纳米SiO2及苯乙烯–丁二烯共聚物(SBS)为改性剂,研究其对基质沥青的改性作用。针对各改性剂不同的结构属性确定了相应的改性沥青制备工艺。通过针入度、软化点、延度和Brookfield黏度等路用性能常规指标以及车辙因子、零剪切黏度、弯曲蠕变劲度等非常规试验指标评价了纳米层状硅酸盐改性沥青和复合材料改性沥青的路用性能。结果表明这些纳米材料改性沥青的路用性能得到了显著改善。

  13. Performance experiments of carbon fiber-reinforced conductive SBS modified asphalt mixture%碳纤维导电SBS改性沥青混合料性能试验

    Institute of Scientific and Technical Information of China (English)

    查旭东; 蔡良; 曹艳霞

    2014-01-01

    In order to analyze pavement performances and ice-melting effects of conductive asphalt concrete,the chopped polyacrylonitrile-based carbon fibers were incorporated into SBS modified asphalt mixture AC-13C to prepare the carbon fiber-reinforced conductive modified asphalt mixtures.Five kinds of carbon fiber contents were selected respectively to conduct the laboratory experiments such as mix ratio design,pavement performances and simulated ice-melting etc.The results show,with the increase of carbon fiber content,the optimum asphalt-aggregate ratios of SBS modified asphalt mixture increase linearly;the dy-namic stability,the immersion residual Marshall stability and the freeze-thaw split strength ratios change in parabolic relationship;the low-temperature flexural-tensile strengths and the failure strains increase in"S"curve,but the stiffness moduli decrease in"Z"curve.It il-lustrates when the proper carbon fibers were incorporated into the SBS modified asphalt mixture,the pavement performances such as high-temperature anti-rutting,low-tempera-ture anti-cracking and moisture damage resistance etc can be improved because of the bridg-ing,reinforced and toughening effects of carbon fiber.However,the excessive carbon fibers can cause the decrease of enhancement effect because of poor dispersion and easy cluster. Simultaneously,when the carbon fiber contents are more than 0.3%,the carbon fibers in-side mixtures are lapped each other to form the good conductive network with the fine ice-melting results.On the whole,when the carbon fiber content is 0.4%,the pavement per-formances,the electrical conductivity and the ice-melting efficiency of carbon fiber-rein-forced SBS modified asphalt mixture are the best.%为了分析导电沥青混凝土的路用性能和融冰效果,将短切聚丙烯腈基碳纤维掺入 SBS改性沥青混合料 AC-13 C中,制备成碳纤维导电改性沥青混合料。选取5种碳纤维掺量分别进行了配合比设计、路用性能和模拟

  14. A Study on the Properties and Chloride Resistance of Modified Sulfur Concrete for Nuclear Power Plant and Marine Structures

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Soon Myun; Chang, Hyun Young; Park, Heung Bae [KEPCO EnC, Seongnam (Korea, Republic of)

    2015-05-15

    The mechanical, physical and chemical properties of concrete with modified sulfur have been compared and assessed against ordinary concrete. As its excellent chloride resistance and extended service life have been verified, the technology to apply modified sulfur to the construction of nuclear power plant and marine structures has been developed and secured. Recently, modified sulfur concrete has been applied for road pavement and repair works in more than 20 sites including highway and airport in Korea. Also, in the U.S., Federal Highway Administration and Virginia Department of Transportation are implementing tests to apply modified sulfur to bridge road pavement, and the modified sulfur concrete has been recognized for its good performance. Based on these cases, this study carried out tests on physical, mechanical and chemical properties of concrete after adding modified sulfur by building concrete specimens based on the concrete mix design employed to construct the Shin-Kori Units 3 and 4 containment building. Multiple tests were performed particularly for chemical resistance, a factor directly related to concrete service life. As a result, it has been verified that concrete with 5% modified sulfur content relative to cement weight has equal mechanical properties (compressive strength, tensile strength, etc.) and much better workability (slump change) and chemical resistance (resistance to chloride ion penetration, concrete carbonation) compared with ordinary concrete. Based on this, it has been concluded that an addition of modified sulfur can double the service life of concrete. In general, studies demonstrate that a significant amount of slag should be mixed into concrete to raise chemical resistance (but with decreasing mechanical properties). Considering this, this study is unparalleled.

  15. Experimental study on storage stability of crumb rubber modified asphalt%橡胶改性沥青储存稳定性试验研究

    Institute of Scientific and Technical Information of China (English)

    何亮; 黄晓明; 马育; 庄大新; 马涛

    2011-01-01

    Asphalt rubber (AR) and desulfurized rubber asphalt (DRA) were prepared, and their storage stability tests under different temperature or different storage time were conducted. Research shows that DRA is more segregated than AR after static storage at high temperature. After high speed shearing process, the large desulfurized crumb rubber particles are dispersed as minimal ones in the asphalt , its original particle size will not affect the performance of crumb rubber modified asphalt; but the ordinary crumb rubber mainly keep their particle cores after shearing. After high temperature storage and mechanical blending, the performance stability of DRA is obviously better than that of AR.%制作了普通橡胶沥青和脱硫橡胶沥青,并进行了不同储存温度或不同储存时间条件下2种橡胶改性沥青的稳定性试验.研究表明,脱硫橡胶沥青经高温静态储存后比普通橡胶沥青更易离析.经过高速剪切工艺,大颗粒的脱硫橡胶粒在沥青里大多分散成无明显颗粒的细小物质,其胶粉颗粒大小在2种橡胶沥青的性能比较中不产生影响;而普通橡胶粉剪切后基本保持其原有颗粒核心.热储存橡胶改性沥青经机械搅拌混匀后,脱硫橡胶沥青的针入度、黏度和低温黏度的稳定性明显好于普通橡胶沥青.

  16. 基于微观结构的北美岩沥青改性机理研究∗%Study on the North American rock asphalt modified mechanism based on microstructure

    Institute of Scientific and Technical Information of China (English)

    黄文通; 徐国元; 刘宇; 王端宜

    2015-01-01

    采用软化点实验和动态剪切温度扫描实验分析了北美岩沥青改性沥青的高温性能;利用电子扫描电镜法、荧光显微镜法、差示扫描量热法、核磁共振波谱法,对不同掺量的北美岩沥青改性沥青进行微观结构的改性机理研究。结果表明,北美岩沥青有效提高沥青流变性能和热稳定性能,改善沥青抗车辙能力和耐老化能力。北美岩沥青增强沥青分子间作用力,提高沥青粘度,改善沥青温度敏感性。北美岩沥青对基质沥青存在物理改性和化学改性的双重改性作用。%The softening point test and dynamic shear temperature sweep test have been used to analyze high temperature performance of North American rock modified asphalt.Fluorescence microscopy,differential scan-ning calorimetry and nuclear magnetic resonance spectrum have been used to study modified asphalt microstruc-ture with various mixing amounts of the North American rock asphalt.The results suggest that the North A-merican rock asphalt can:(1 )increase the rheological performance and thermal stability of asphalt effectively, thereby improving the anti-rutting properties and the anti-aging properties of modified asphalt;(2)reinforce as-phalt intermolecular forces,improving viscosity and temperature sensitivity of modified asphalt;(3)the North American rock asphalt has a double modifying function on base asphalt,physically and chemically.

  17. Research on Distribution Rule of Long -Term Durability Performance of Asphalt Concrete in Statistics%沥青混凝土长期耐久性能在统计学上的分布规律研究

    Institute of Scientific and Technical Information of China (English)

    赵前军; 潘红伟; 车小磊

    2012-01-01

    The existing research usually adopts normal distribution to describe the fatigue durability of asphalt concrete, however, due to variability of materials and test environment, the test result of fatigue durability perform- ance has great discreteness. According to a large amount of indoor tests and preferable selection of typical data source, with double parameter Weihull distribution theory, the distribution rule of fatigue durability performance of asphalt concrete in statistics is verified and fatigue life equation under the conditions of different probability of fail- ure is obtained through regression. The result shows that the distribution features of fatigue durability of asphalt con- crete under complicated conditions of multi factors could be described well with Weibull distribution theory.%已有研究通常采用正态分布来描述沥青混凝土的疲劳耐久性,但是由于材料本身以及试验环境条件的变异性,试验所得的疲劳耐久性能具有很大的离散性。依据大量室内试验并优选代表性强的数据源,利用双参数Weibull分布理论验证沥青混凝土材料的疲劳耐久性能在统计学上的分布规律,并回归得到了不同失效概率条件下的疲劳寿命方程。结果表明:Weibull分布理论能够较好地描述多因素复杂条件下沥青混凝土的疲劳耐久性分布特征。

  18. The Construction Technology and Quality Control of Hot Mix Asphalt Concrete Pavement%热拌沥青混凝土路面施工工艺及质量控制

    Institute of Scientific and Technical Information of China (English)

    卢宪法

    2014-01-01

    热拌沥青混凝土作为公路路面施工的重要组成部分,其选材、施工工艺、质量控制等流程对公路的建成性能都具有决定性的影响。笔者结合近年来的学习工作经验,主要从材料、沥青混凝土的配比、施工工艺、质量控制几个方面作简要阐述。%Hot mix asphalt concrete as an important part of highway pavement construction, the material selection, constr-uction technology and quality control hasa decisive influence on the process of highway completed performance. The author combines with work experience in recent years to elaborate from several aspects of material, the ratio of asphalt concrete, construction technology, and quality control, etc.

  19. Performance Evaluation of Asphalt Modified with Municipal Wastes for Sustainable Pavement Construction

    Directory of Open Access Journals (Sweden)

    Muhammad Nasir Amin

    2016-09-01

    Full Text Available The severe hot temperature and high traffic loadings in the Kingdom of Saudi Arabia (KSA are causing distress in flexible pavements within a few years of service. Secondly, the conventional bitumen extracted from Saudi oil refineries have a performance grade of 64-10 (PG 64-10, which does not meet the SuperPave performance grade requirement for most of the KSA’s regions. In order to improve the performance grade of bitumen, different percentages of municipal wastes (plastic and crumb rubber were used as bitumen additives. The performance of bitumen at low, intermediate, and high temperatures was evaluated. This is important as the waste production is rising significantly due to the fast urbanization and high population growth in the KSA. Particularly, when there are very few ways of recycling these wastes (municipal, as well as industrial, which in fact have great impact on the environment. High-density polyethylene (HDP, low-density polyethylene (LDP, and crumb rubber (CR with 5%, 10%, and 15% by weight of bitumen, were mixed with the base bitumen (PG 64-10. Rotational viscometer (RV, dynamic shear rheometer (DSR, and bending beam rheometer (BBR were used to evaluate the viscosity, rutting, fatigue, and low-temperature behavior of base and modified binders. The test results indicated that the rutting (permanent deformation and fatigue resistance were significantly improved in modified binders due to the improvement in the visco-elastic properties.

  20. Modified virtual internal bond model for concrete subjected to dynamic loading

    Science.gov (United States)

    Patil, Mayuri

    Concrete is often used as a primary material to build protective structures. There is a wide range of research work being performed to simulate the behavior of reinforced concrete under impact and blast loading. This behavior is studied from both material and structural points of view. The research study presented in this thesis focuses on material aspects of modeling. LS-DYNARTM is an effective software for modeling and finite element analysis of structural members. It allows the user to define the material through commercially available or user-defined constitutive material models. Each material model has a distinct set of parameters to define a material which is further assigned to elements and used for simulations. This research study presents a user defined material model called Modified Concrete Virtual Internal Bond Model (MC-VIB). The basic constitutive model of VIB assumes the body as a collection of randomly oriented material points interconnected by a network of internal bonds. The model was modified by several researchers for different purposes. This research presents the MC-VIB for concrete under dynamic loading and studies its implementation into LS-DYNARTM. The modifications include incorporation of shear behavior and accounting for the difference in behavior of concrete in tension and compression. This project includes the calibration of the model based on stress-strain behavior of single element and cylinder model of concrete. The parameters are based on concrete with a uniaxial compressive strength of 27.6 MPa (4 ksi). These numerical curves are compared to those obtained from conventionally used material models for concrete and standard curves obtained by accepted equations to check the accuracy of prediction. The material model available in LS-DYNARTM requires a number of input parameters to define concrete behavior. These properties are normally derived from actual tests performed on the concrete under consideration. Often the properties are

  1. Concrete

    OpenAIRE

    2015-01-01

    Concrete is a component of coherent transition between a concrete base and a wooden construction. The structure is based on a quantity of investigations of the design possibilities that arise when combining digital fabrication tools and material capacities.Through tangible experiments the project discusses materiality and digitally controlled fabrications tools as direct expansions of the architect’s digital drawing and workflow. The project sees this expansion as an opportunity to connect th...

  2. Evaluation on Low Temperature Performance of Recycled Asphalt Mixture Using Warm Mix Asphalt Technology

    OpenAIRE

    Xiaolan Duan,; Chunge Li

    2015-01-01

    In this paper, the basic idea is about the recycled technology of asphalt mixture, more in-depth study of the lowtemperature performance of warm mix asphalt(WMA).First of all, Including the evaluation of low temperature performance of WMA made of reclaimed asphalt pavement (RAP) (passed and not passed 2.36mm screen), and the influence of WMA with RAP mixed of different dosage of dispersant. Then, using the SBS modified asphalt and base asphalt were test at low temperature, researc...

  3. Possibilities for improving corrosion protection of reinforced concrete by modified hydrotalcites: a literature review

    NARCIS (Netherlands)

    Yang, Z.; Fischer, H.R.; Polder, R.B.

    2012-01-01

    Modified Hydrotalcites (MHTs) represent a group of technologically promising materials for improving corrosion protection in concrete owing to their low cost, relative simplicity of preparation, and plenty of composition variables. Numerous academic and commercial studies on MHTs have been carried o

  4. A new smart additive of reinforced concrete based on modified hydrotalcites: Preparation, characterization and anticorrosion applications

    NARCIS (Netherlands)

    Yang, Z.; Fischer, H.; Polder, R.

    2012-01-01

    A carbonate form of Mg-Al-hydrotalcite and its p-aminobenzoate (pAB) modified derivative (i.e.,Mg(2)Al-pAB) were synthesized and characterized by means of XRD and FT-IR. The anticorrosion behavior was evaluated based on open circuit potential (OCP) of carbon steel in simulated concrete pore solution

  5. Analysis on the Application of Modified Emulsified Asphalt in Expressway Pavement Construction%改性乳化沥青在高速路面施工中的应用分析

    Institute of Scientific and Technical Information of China (English)

    张佳

    2013-01-01

    This article discusses the technology characteristics of modified emulsified asphalt, carries out the analysis and dis-cussion of the modified emulsified asphalt applied in the exp-ressway pavement construction, and has a deep understanding to the relevant contents, aims at providing some enlightenment and thinking to the application of modified emulsified asphalt.%文章论述了改性乳化沥青的技术特点,并着重就改性乳化沥青在高速路面施工中的应用做出了分析与探讨,对其相关内容有了一个深入的了解,意在为改性乳化沥青的现实应用提供借鉴与思路。

  6. 基于性能的水坝防渗面板沥青混凝土设计方法%Performance-based design-method for asphalt-concrete as seepage prevention face of embankment dams

    Institute of Scientific and Technical Information of China (English)

    葛折圣

    2011-01-01

    To improve the mechanical properties of asphalt-concrete in embankment dam seepage prevention facing, a method for determination of the minimum value of voids in coarse aggregate and the index of skeleton-interlocking of densegap graded mixture were put forward, in order to improve the coarse aggregate void filling method. A dense-gap-grade full- asphalt-concrete was designed by using the improved method, and its properties were tested through Marshal-test, slop-flow test, permeability-test and small girder bending test at low temperature. These properties satisfied the requirements of the Specifications for Construction of Hydraulic Roller Compacted Bituminous Concrete. The results show that the improved coarse aggregate void filling method is an effective performance-based method for the design of asphalt-concrete.%为全面提高水坝防渗面板沥青混凝土力学性能,提出粗集料间隙率最小值的测定方法和沥青混凝土中粗集料骨架嵌挤的新标准,改进基于性能的粗集料空隙填充法,用于设计一种水坝防渗面板密断级配富沥青混凝土;通过试验评价设计混凝土的稳定度、流值、斜坡流淌值、渗透系数和低温弯拉破坏应变等力学性能,各项力学指标均满足《水工碾压式沥青混凝土施工规范》(DL/T5363-2006)的要求。结果表明,改进的粗集料空隙填充法是一种基于性能的有效的沥青混凝土组成设计方法,具有广泛的推广和应用价值。

  7. Waste Tire Particles and Gamma Radiation as Modifiers of the Mechanical Properties of Concrete

    Directory of Open Access Journals (Sweden)

    Eduardo Sadot Herrera-Sosa

    2014-01-01

    Full Text Available In polymer reinforced concrete, the Young’s modulus of both polymers and cement matrix is responsible for the detrimental properties of the concrete, including compressive and tensile strength, as well as stiffness. A novel methodology for solving such problems is based on use of ionizing radiation, which has proven to be a good tool for improvement on physical and chemical properties of several materials including polymers, ceramics, and composites. In this work, particles of 0.85 mm and 2.80 mm obtained from waste tire were submitted at 250 kGy of gamma radiation in order to modify their physicochemical properties and then used as reinforcement in Portland cement concrete for improving mechanical properties. The results show diminution on mechanical properties in both kinds of concrete without (or with irradiated tire particles with respect to plain concrete. Nevertheless such diminutions (from 2 to 16% are compensated with the use of high concentration of waste tire particles (30%, which ensures that the concrete will not significantly increase the cost.

  8. SBS/金属皂复配改性沥青性能研究%Research on the performance of SBS and metal soap composite modified asphalt

    Institute of Scientific and Technical Information of China (English)

    梁寿国; 王铁宝; 张涛; 陈淼

    2011-01-01

    研究了金属皂对SBS改性沥青常规性能、储存稳定性以及微观组织的影响,并测试了SBS/佥属皂复配改性沥青混合料的路用性能.研究结果表明:SBS/金属皂复配改性沥青的最佳配比为4%SBS+0.45%金属皂.其SBS改性沥青储存稳定性效果最佳,软化点差仅为0.3℃,PI值由0.39提高到0.93,并且金属皂的含量对低温延度的影响较小.在此配比条件下,沥青混合料的抗高温车辙性能和抗低温开裂性能均提高为原来的1.2倍.这主要是因为金属皂加入后,促使SBS与沥青分子之间交联,使改性沥青中聚合物分散非常均匀,改善了SBS和沥青的相容性.%The influence of metal soap on the normal performance, storage stability, microstmcture of SBS modified asphalt was investigated, and the performance of composite modified asphalt mixture was also tested. The results show that the optimum of composite modified asphalt was 4%SBS and 0.45%metal soap. The addition of 0.45 percent of metal soap gets the best storage stability. The softening point difference was only 0.3℃. The PI index was increased from 0.39 to 0.93 and the influence on the low temperature ductility was not obvious. Under this condition, rutting resistance at high temperature and cracking resistance at low temperature were both improved and the ratiowas 1.2. It is mainly because the addition of the metal soap can improve erosslinking and it makes the polymer disperse so homogeneous that the compatibility is improved significantly between SBS and asphalt.

  9. Influence of Garlic Powder on Properties of Asphalt Modified with High Content Rubber Powder%大蒜粉对高用量胶粉改性沥青性能的影响

    Institute of Scientific and Technical Information of China (English)

    刘欣; 万振高; 王乐英; 邵晓瑜

    2016-01-01

    以大蒜粉作胶粉改性沥青的降粘剂,采用布氏粘度计测试了不同胶粉用量+不同大蒜粉用量的改性沥青粘度,还测试了添加大蒜粉后胶粉改性沥青的软化点、针入度和延度等性能,并讨论了降粘剂对胶粉改性沥青降粘效果的影响。结果表明,大蒜粉对胶粉改性沥青有明显的降粘效果,对其他性能也有一定影响;当基质沥青中加入25%胶粉和3%大蒜粉后降粘效果和性能均最佳。%By using garlic powder as viscosity reducer of asphalt modified with rubber powder ,the viscosity of asphalt modified with different content of rubber powder and different content of garlic powder was measured by Brookfield viscometer .The softening point ,penetration and ductility of the asphalt modified with rubber powder were tested after adding garlic powder ,and the influence of vis‐cosity reducer on viscosity reduction effect of the modified asphalt was discussed .The results showed that garlic powder had apparent viscosity‐reducing effect to the modified asphalt ,and the other proper‐ties were also effected .Viscosity‐reducing effect and properties were good after adding 25% rubber pow der and 3% garlic pow der to the base asphalt ,respectively .

  10. 聚合物改性沥青水泥砂浆的试验研究%Experimental research on the polymer modified asphalt and cement mortar

    Institute of Scientific and Technical Information of China (English)

    曾三海; 王鹏; 王光辉; 比干旭光

    2012-01-01

    This paper mainly researched mechanical properties of polymer modified emulsified asphalt and cement mortar and analyzed the experiment results. The study results showed that neoprene latex can, to a certain extent, improve the workability of polymer modified emulsified asphalt and cement mortar, reduce pressure off ratio, improve failure modes of the mortar, and fundamentally improve the capability of resistance to brittle fracture at low-temperature and resistance to deformation at high temperature.%研究了聚合物改性乳化沥青水泥砂浆的力学性能,并对其试验结果进行了分析.研究表明,氯丁橡胶乳液可以在一定程度上改善乳化沥青水泥砂浆的工作性,降低压折比,改善砂浆的破坏形态,可从根本上改善水泥乳化沥青砂浆的低温抗脆裂和高温抗变形能力.

  11. Research on the properties of SBS modified asphalt with silica hydrated%SBS/白炭黑复配改性沥青性能的研究

    Institute of Scientific and Technical Information of China (English)

    陈淼; 陈浩; 王洪涛; 聂英斌

    2013-01-01

    通过对SBS单一改性沥青和SBS/白炭黑复配改性沥青基本性能的测试,研究了不同改性剂及其掺量对基质沥青性能的影响.结果表明:掺4%SBS改性沥青能够改善基质沥青的高温性能、低温性能和感温性能;掺4%SBS+3%白炭黑复配改性沥青也能改善基质沥青的高温性能、低温性能和感温性能,并且其改善效果优于掺4%SBS单一改性沥青.%In this paper,the properties of SBS modified asphalt with/without silica hydrated were tested,the influence of different modified asphalt and different content of it on the base bitumen were also researched.The results showed that:the hightemperature behavior,low-temperature performance and sensitivity for temperature were improved with 4%SBS content,and the properties can also be improved with 4%SBS and 3% silica hydrated,the latter was better than the former.

  12. Rheological behaviour of polymer-modified bituminous mastics : a comparative analysis between physical and chemical modification

    OpenAIRE

    Shivokhin, Maxim; García Morales, Moisés; Partal López, Pedro; Cuadri Vega, Antonio Abad; Gallegos Montes, Críspulo

    2012-01-01

    Mastic, a bitumen/filler blend which naturally forms when bitumen is mixed with aggregates is the actual product used to bind coarse mineral particles in the asphalt mixtures. As a result, the characterisation of mastics is essential to improve the understanding of the response and performance of asphalt concrete pavements. On the other hand, the lack of experimental data concerning the behaviour of mastics and, above all, polymer-modified mastics has been lately claimed. In that sense, this ...

  13. Rheological behaviour of polymer-modified bituminous mastics : a comparative analysis between physical and chemical modification

    OpenAIRE

    Shivokhin, Maxim; García Morales, Moisés; Partal López, Pedro; Cuadri Vega, Antonio Abad; Gallegos Montes, Críspulo

    2012-01-01

    Mastic, a bitumen/filler blend which naturally forms when bitumen is mixed with aggregates is the actual product used to bind coarse mineral particles in the asphalt mixtures. As a result, the characterisation of mastics is essential to improve the understanding of the response and performance of asphalt concrete pavements. On the other hand, the lack of experimental data concerning the behaviour of mastics and, above all, polymer-modified mastics has been lately claimed. In that sense, this ...

  14. Performance of Recycled Porous Hot Mix Asphalt with Gilsonite Additive

    Directory of Open Access Journals (Sweden)

    Ludfi Djakfar

    2015-01-01

    Full Text Available The objective of the study is to evaluate the performance of porous asphalt using waste recycled concrete material and explore the effect of adding Gilsonite to the mixture. As many as 90 Marshall specimens were prepared with varied asphalt content, percentage of Gilsonite as an additive, and proportioned recycled and virgin coarse aggregate. The test includes permeability capability and Marshall characteristics. The results showed that recycled concrete materials seem to have a potential use as aggregate in the hot mix asphalt, particularly on porous hot mix asphalt. Adding Gilsonite at ranges 8–10% improves the Marshall characteristic of the mix, particularly its stability, without decreasing significantly the permeability capability of the mix. The use of recycled materials tends to increase the asphalt content of the mix at about 1 to 2% higher. With stability reaching 750 kg, the hot mix recycled porous asphalt may be suitable for use in the local roads with medium vehicle load.

  15. Development of criteria for the use of asphalt-rubber as a Stress-Absorbing Membrane Interlayer (SAMI)

    Science.gov (United States)

    Newcomb, D. E.; McKeen, R. G.

    1983-12-01

    This report documents over 2 years of research efforts to characterize asphalt-rubber mixtures to be used in Stress-Absorbing Membrane Interlayers (SAMI). The purpose of these SAMIs is to retard or prevent reflection cracking in asphalt-concrete overlays. Several laboratory experiments and one field trial were conducted to define significant test methods and parameters for incorporation into construction design and specification documents. Test methods used in this study included a modified softening point test, force-ductility, and Schweyer viscosity. Variables investigated included (1) Laboratory-mixing temperature; (2) Rubber type; (3) Laboratory storage time; (4) Laboratory storage condition; (5) Laboratory batch replication; (6) Laboratory mixing time; (7) Field mixing time; (8) Laboratory test temperature; (9) Force-Ductility elongation rates; and (10) Asphalt grade. It was found that mixing temperature, mixing time, rubber type, and asphalt grade all have significant effects upon the behavior of asphalt-rubber mixtures. Significant variability was also noticed in different laboratory batch replications. Varying laboratory test temperature and force-ductility elongation rate revealed further differences in asphalt-rubber mixtures.

  16. Mechanical Properties of Light Weight Polymer Modified Concrete Made with Chopped Rubber Tires

    Directory of Open Access Journals (Sweden)

    Hassanien Mohammed Thiyab

    2017-07-01

    Full Text Available Lightweight concrete is highly used as loaded and unloaded parts in structures. The low values of compressive strength leads to the production of lightweight concrete blocks that can be used in partitions and the types that have more than 17 MPa and in some structural members that are not highly loaded. This research includes study of mechanical properties of this type of concrete which produced from the waste materials ( chopped rubber tires that are used as a percentage from coarse aggregates by the replacing method. The replacement was as 10%, 20%, 30%, 40% and 50% by weight of coarse aggregates. The mixes were modified by using the styrene butadiene rubber (SBR to increase the values of the mechanical properties and durability. The aim of this investigation is to product special mixes of concrete with a low density and good mechanical properties to reduce the dead load and more economic construction . This study proof the CRT effect on compressive strength whereas it dropped from 62.5 Mpa to 40.8 Mpa by increase percentage of the CRT from 10% to 50%, but in the same time the density lowered up to 33%. The mixes with 10%, 20%, 30% can be regarded as a structural lightweight concrete (exceeded 17 MPa and the other mixes can be used for the production of lightweight blocks used in partitions.

  17. The Asphalt Handbook.

    Science.gov (United States)

    Asphalt Inst., College Park, MD.

    The new and completely revised edition of the Asphalt Handbook, a standard reference work in the field of asphalt technology and construction, summarizes with reference the information contained in other Asphalt Institute technical manuals. Major areas discussed include the following--(1) uses of asphalt, (2) terms relating to asphalt and its…

  18. Porous Flame-retarded Asphalt Pavement for Highway Tunnel

    Institute of Scientific and Technical Information of China (English)

    HU Shuguang; HUANG Shaolong; Ding Qingjun

    2008-01-01

    A new way to improve the tunnel fire protection by using flame-retarded porous asphalt pavement containing ATH powders was introduced. Based on the miniature burning test designed and conducted, the burning time and temperature of porous asphalt (PA) and flame-retarded porous asphalt (FRPA) were studied comparing with cement concrete pavement, dense-graded HMA and S MA. Results of burning test and pavement performance test indicate that FRPA is appropriate and suitable as the pavement material of highway tunnel.

  19. A New Life for Cross-Linked Plastic Waste as Aggregates and Binder Modifier for Asphalt Mixtures

    Directory of Open Access Journals (Sweden)

    Liliana M. B. Costa

    2017-06-01

    Full Text Available Every year, millions of tons of plastic waste, with potential to be reused, are wasted in landfills. Based on a literature review and in a local market analysis, cross-linked polyethylene (PEX waste arose as the material with the greatest potential to be tested for incorporation in asphalt mixtures due to the difficulty in its recycling and the lack of solutions for its reuse. Thus, in the present work, mixtures produced with and without PEX were tested in order to compare their performance, aiming at understanding if this waste could successfully be used as an alternative material for this type of application. Thus, water sensitivity, rutting resistance, stiffness modulus and fatigue cracking resistance tests were carried out on asphalt mixtures with up to 5% PEX. Based on the results obtained, it can be concluded that the incorporation of PEX in asphalt mixtures is a viable solution for paving works, especially when high service temperatures are expected. It also decreases the density of the mixture, which can be attractive to lighten structures. Thus, this technology contributes to give new life to cross-linked polyethylene plastic waste.

  20. Influence of Crumb-Rubber in the Mechanical Response of Modified Portland Cement Concrete

    Directory of Open Access Journals (Sweden)

    J. Retama

    2017-01-01

    Full Text Available The influence of crumb-rubber on the mechanical properties of Portland cement concrete (PCC is studied by experimental tests and numerical simulations. The main hypothesis of the study is that replacing part of the stone aggregate with crumb-rubber in the mix modifies the energy dissipation during the cracking process and affects the concrete behaviour under monotonically increasing loads. The experimental research program characterizes the mechanical properties of PCC for three different types of concrete with a variable content of crumb-rubber. The experimental results showed that fracture energy and other properties are directly related to the rubber fineness used in the mixture. The material properties derived for these laboratory tests are used to study, by numerical models, its response through its damage evolution. The numerical model used to simulate the damage evolution of the concrete is the Embedded Discontinuity Method (EDM. One characteristic of the EDM is that it does not need to modify the mesh topology to propagate the damage through the continuum solid. For this study, the Disk-Shaped Compact Tension specimen geometry, normed by the D7313-13 of the ASTM, is used. Results showed that the numerical methods provide good approximation of the experimental curve in the elastic and softening branches.

  1. Sustainable asphalt pavement: Application of slaughterhouse waste oil and fly ash in asphalt binder

    Science.gov (United States)

    Sanchez Ramos, Jorge Luis

    Increasing energy costs, lack of sufficient natural resources and the overwhelming demand for petroleum has stimulated the development of alternative binders to modify or replace petroleum-based asphalt binders. In the United States, the petroleum-based asphalt binder is mainly used to produce the Hot Mix Asphalt (HMA). There are approximately 4000 asphalt plants that make 500 million tons of asphalt binder valued at roughly 3 billion/year. The instability of the world's oil market has pushed oil prices to more than 80 per barrel in 2012, which increased the cost of asphalt binder up to $570 per ton. Therefore, there is a timely need to find alternative sustainable resources to the asphalt binder. This paper investigates the possibility of the partial replacement of the asphalt binder with slaughterhouse waste and/or fly ash. In order to achieve this objective, the asphalt binder is mixed with different percentages of waste oil and/or fly ash. In order to investigate the effect of these additives to the performance of the asphalt binder, a complete performance grade test performed on multiple samples. The results of the performance grade tests are compared with a control sample to observe how the addition of the waste oil and/or fly ash affects the sample. Considering the increasing cost and demand of asphalt, the use of slaughterhouse waste oil and/or fly ash as a partial replacement may result in environmental and monetary improvements in the transportation sector.

  2. Effect of Crumb Rubber and Warm Mix Additives on Asphalt Aging, Rheological, and Failure Properties

    Science.gov (United States)

    Agrawal, Prashant

    Asphalt-rubber mixtures have been shown to have useful properties with respect to distresses observed in asphalt concrete pavements. The most notable change in properties is a large increase in viscosity and improved low-temperature cracking resistance. Warm mix additives can lower production and compaction temperatures. Lower temperatures reduce harmful emissions and lower energy consumption, and thus provide environmental benefits and cut costs. In this study, the effects of crumb rubber modification on various asphalts such as California Valley, Boscan, Alaska North Slope, Laguna and Cold Lake were also studied. The materials used for warm mix modification were obtained from various commercial sources. The RAF binder was produced by Imperial Oil in their Nanticoke, Ontario, refinery on Lake Erie. A second commercial PG 52-34 (hereafter denoted as NER) was obtained/sampled during the construction of a northern Ontario MTO contract. Some regular tests such as Dynamic Shear Rheometer (DSR) and Bending Beam Rheometer (BBR), Multiple Stress Creep Recovery (MSCR) and some modified new protocols such as the extended BBR test (LS-308) and the Double-Edge Notched Tension (DENT) test (LS-299) are used to study, the effect of warm mix and a host of other additives on rheological, aging and failure properties. A comparison in the properties of RAF and NER asphalts has also been made as RAF is good quality asphalt and NER is bad quality asphalt. From the studies the effect of additives on chemical and physical hardening tendencies was found to be significant. The asphalt samples tested in this study showed a range of tendencies for chemical and physical hardening.

  3. Asbestos Tailings as Aggregates for Asphalt Mixture

    Institute of Scientific and Technical Information of China (English)

    LIU Xinoming; XU Linrong

    2011-01-01

    To use many asbestos tailings collected in Ya-Lu highway, and to explore the feasibility of using asbestos tailings as aggregates in common asphalt mixtures, and properties of some asphalt mixtures were evaluated as well. X-ray diffraction (XRD), X-ray fluorescent (XRF), and atomic absorption spectrophotometry (AAS) were employed to determine the solid waste content of copper, zinc, lead, and cadmium. Volume properties and pavement performances of AC-25 asphalt mixture with asbestos tailings were also evaluated compared with those with basalt as aggregates.XRD and XRF measurement results infer that asbestos tailing is an excellent road material. Volume properties of AC-25 asphalt mixture with asbestos tailings satisfied the related specifications. No heavy metals and toxic pollution were detected in AAS test and the value of pH test is 8.23, which is help to the adhesion with asphalt in the asphalt concrete. When compared with basalt, high temperature property and the resistance to low temperature cracking of AC-25 asphalt mixture was improved by using asbestos tailings as aggregates. In-service AC-25 asphalt pavement with asbestos tailings also presented excellent performance and British Pendulum Number (BPN) coefficient of surface.

  4. Experimental Research on the Gravel Aggregate Water Stability Performance of Asphalt Concrete Core Wall%采用砾石骨料的心墙沥青混凝土水稳定性能试验研究

    Institute of Scientific and Technical Information of China (English)

    何建新; 朱西超; 杨海华; 王文政

    2014-01-01

    To further study the water stable performance of using gravel aggregate's core wall asphalt concrete ,gravel aggregate as raw material preparation of asphalt concrete specimen ,water stability test ,soaking and vacuum saturated marshal test and improved freeze-thaw splitting test were carried out .The results show that water stability specimen stability coefficient is 0 .99 ,and meets the regulatory requirements .immersion and vacuum water saturated specimens with immersion time increasing the residual stability de‐cline ,the immersion specimens and vacuum saturated specimens'residual stability biggest decline rates are 1 .4% and 3 .9% respec‐tively ,the decline is not obvious .The porosity was still able to meet the specification requirements of within 2% .It can be seen that the core wall asphalt concrete's water stability is still guaranteed under harsh conditions .This paper serves as a reference for impro‐ving the water stability of asphalt concrete core wall test methods and gravel aggregate applications .%为进一步研究采用砾石骨料的心墙沥青混凝土水稳定性能,以砾石骨料为原材料制备沥青混凝土试件,进行了水稳定试验、浸水及真空饱水马歇尔试验和改进的冻融劈裂试验,试验结果表明:水稳试件的水稳定系数为0.99,满足规范大于0.90的要求;浸水及真空饱水试件随着浸泡时间的增加其残留稳定度有所下降,浸水试件及真空饱水试件残留稳定度最大下降率分别为1.4%、3.9%,下降不明显。劈裂抗拉强度比随冻融循环次数的增加有所下降,劈裂抗拉强度比最大下降率为5%;冻融劈裂试件密度随着冻融循环次数的增加略有下降,下降值在0.2%~0.9%之间,但孔隙率仍能满足规范中不大于2%的要求,可以看出心墙沥青混凝土在恶劣试验条件下水稳定性仍然是有保证的。为完善心墙沥青混凝土水稳定性试验方法及砾

  5. 老化对 PE改性沥青混合料高温性能的影响%Influence of Different Aging State on the Performance of PE Modified Asphalt Mixture at High-Temperature

    Institute of Scientific and Technical Information of China (English)

    宋玉珠

    2014-01-01

    Taking AH-70 asphalt as base asphalt,the modified asphalt mixture was prepared by polyethylene (PE ),The high temperature performance of PE modified asphalt mixture were studied according to wheel rutting test,the static creep test and dynamic creep test,in this study,the influence of aging on the dynamic stability,stiffness modulus, permanent deformation and flow number were researched.The results show that the high temperature performance of PE modified asphalt mixture were improved when aged.Rutting test reflects the deformation of asphalt mixture focused on the short term aging stage,and the aging influenced the stiffness modulus,and flow number,while decreased the perma-nent deformation.%以 AH-70沥青为基质沥青,选用 PE 为改性剂制备改性沥青混合料,考察了老化对 PE 改性沥青混合料高温性能的影响,并采用了车辙试验、静态蠕变试验和动态蠕变试验,分析了老化对 PE 改性沥青混合料动稳定度、劲度模量、永久变形量及流变次数的影响。试验结果表明,PE 改性沥青混合料在老化后,其高温稳定性得到了提高,车辙试验反映沥青混合料的变形主要集中在短期老化阶段。老化后的沥青混合料劲度模量增大,其永久变形量降低、流变次数增大。

  6. Research on the Fracture Properties and Modification Mechanism of Polyester Fiber and SBR Latex Modified Cement Concrete

    Directory of Open Access Journals (Sweden)

    Mingkai Zhou

    2016-01-01

    Full Text Available Polyester fiber and SBR latex cement concrete is prepared as pavement surface material; its fracture properties including fracture toughness, fracture energy, CMOD, and flexural strength are studied comparing with those of normal concrete (NC, polyester fiber modified concrete (FMC, SBR polymer modified concrete (SMC, and the combination of polyester fiber and SBR polymer modified concrete (FSMC. The modification mechanism of the latex and fiber on the concrete was also studied by the methods including X-ray test, chemically combined water, heat of hydration, water loss, and scanning electron microscope. Results indicated that the concrete modified by latex and polyester fiber has flexural strength, fracture toughness, and fracture energy of 44.4%, 397.0%, and 462.8% higher than the reference normal concrete, the polymer retarded the hydration process and reduced the hydration degree of cement at early age, while the hydration degree is promoted by the polymer film for its excellent water resistance after 28 d, and the bond between the fiber and cement paste is improved by the latex.

  7. Application of Permeable Asphalt Concrete Surface Layer in Municipal Road Engineering%透水性沥青混凝土面层在市政道路工程中的应用

    Institute of Scientific and Technical Information of China (English)

    严应斌

    2012-01-01

    改革开放之后,我国的经济发展日新月异,城市社会发展越来越快,而交通作为经济发展的基础,也得到了速度的发展,而市政道路的质量高低,直接影响着交通的顺畅与否,所以越来越得到政府的重视.城市市政道路工程是一个城市的形象工程,其工程质量关系到政府的形象和城市市容市貌.本文通过对透水性沥青混凝土面层的材料选择、配合比等方面的探讨,研究结果表明,透水性沥青混凝土面层具有较好的路用性能、经济效益和社会效益.%After the reform and opening up, the rapid development of China's economy and the increasingly rapid development of urban society, as the basis of economic development, traffic has been gotten rapid development, while the quality of municipal roads directly affect traffic smoothly or not, so it is gotten more and more attention by the government. The city municipal road project is the urban image engineering and its quality of the project is related to the government's image and the urban appearance of the city. This paper discussed permeable asphalt concrete surface layer's choice of materials, mix proportion. The study results show that permeable asphalt concrete surface layer has good pavement performance, economic and social benefits.

  8. The Dynamic Model Based on PFC of Asphalt Concrete Cutting Process and Optimization of Tools Installation%基于PFC的沥青混凝土铣削仿真及刀具安装优化

    Institute of Scientific and Technical Information of China (English)

    周里群; 李军; 邢国

    2012-01-01

    In this paper, based on the superiority of the simulation of the discrete element method with the rheological properties on asphalt concrete, it simulates milling machine cutting process of asphalt concrete , overcome the limitations of the macro continuity hypothesis based on traditional continuum mechanics model, and can make this cutting process visible from microcosmic angle. The research results indicated that the model checked by uniaxial compression test, gets change rule of cutting force and friction force in different cutting angle on cutting knife surface of cutting tools, and gets the conclusion that 5~20 degrees cutting angle in installation tools is good to tools' life.%基于离散元对沥青混凝土流变特性模拟的优越性,对其切削过程进行动态仿真,克服了传统连续介质力学模型的宏观连续性假设的局限性,可以从徽观角度对切削过程进行可视化的数值模拟.研究结果表明:通过单轴压缩试验校正后的模型,得到在不同切削角下切削过程中刀具前刀面受力变化规律,并得出刀具在安装工程中优先选择5~20°切削角的结论,为工程实际提供了参考.

  9. Study on mix proportion design and performance of casting asphalt concrete composed of natural gravel aggregate%采用天然砾石骨料的浇筑式沥青混凝土配合比设计及性能研究

    Institute of Scientific and Technical Information of China (English)

    郭鹏飞; 何建新; 刘亮; 刘录录

    2012-01-01

    在进行沥青混凝土配合比设计时,为保证骨料与沥青的粘附性及心墙的安全可靠性,沥青混凝土骨料多采用碱性岩石破碎的人工碎石,当采用天然砾石骨料配置沥青混凝土时,材料的配合比及水稳定性越来越受到工程界的关注.本文采用广泛分布于新疆的天然砂砾料作为原材料,进行沥青混凝土配合比设计.提出当丁朴荣公式中沥青含量为8.3% ~8.6%、填料用量为10% ~ 14%、级配指数0.33或0.34时,采用天然砂砾料配置的沥青混凝土仍具有良好的流动性能,同时也符合沥青混凝土的水稳定性要求.%In the mix proportion design of casting asphalt concrete, alkaline and broken artificial stone of the aggregate of asphalt concrete is taken to guarantee adhesion between aggregate and asphalt as well as reliability of the core, when natural gravel aggregate is applied in configurating asphalt concrete, mix proportion of material and water stability attract more and more attention in engineering field. This paper used natural gravel which is widely distributed in Xinjiang to cany out. It indicates when asphalt content is 8. 3% to 8. 6% .mineral filler content is 0% to 14% and grading index is 0. 33 or 0. 34 in Ding Purong formula, asphalt concrete using natural gravel aggregate configuration has good fluidity and also accords with the requirement of water stability for asphalt concrete.

  10. Experimental Study on Shear Fatigue Behavior and Stiffness Performance of Warm Mix Asphalt by adding Synthetic Wax

    CERN Document Server

    Petit, Christophe; Canestrari, Francesco; Pannunzio, Valter; Virgili, Amadeo

    2012-01-01

    Synthetic waxes produced by standard and registered processes may be used to manufacture Warm Mix Asphalt (WMA), which is a modified asphalt concrete produced, applied and compacted at temperatures below those typically required. This feature leads to environmental benefits, such as reduced energy consumption, gas and fume emissions, as well as to economic/operational advantages, such as lower production costs and greater hauling distances for extended construction seasons with tighter schedules. The present article serves to compare the mechanical performance of a WMA produced by adding synthetic wax with a traditional Hot Mix Asphalt (HMA) specimen, in terms of shear fatigue response and both complex and stiffness moduli. The experimental results and related modeling work demonstrate that adding synthetic wax into the WMA composition does not hinder either the destructive or non-destructive performance of an HMA, and this finding is corroborated by respectively measuring fatigue life and stiffness.

  11. 废旧塑料改性沥青混合料动态模量研究%Research on dynamic modulus of waste plastic modified asphalt mixture

    Institute of Scientific and Technical Information of China (English)

    张倩; 谢来斌; 李彦伟; 何勇海; 刘建

    2011-01-01

    Waste plastic is reused in pavement engineering in this research. The purpose of the study is to probe the possibility of using waste plastic in asphalt mixture as a kind of modifier so as to find a way to solve the problem of the waste plastic disposal. High Density Polyethylene plastic bags obtained from supermarket were shredded into pieces and were added into asphalt mixture at three percentages of 2%, 5% and 8%. The corresponding control samples were also made and tested. Three different temperatures were used (4°C, 21. 3°C and 39. 2°C) and the frequencies ranged from 0. 1 Hz to 25 Hz in this dynamic modulus test. When compared with the test results of the control samples, almost all the dynamic modulus of the plastic modified samples( except 4 results) are greater than those of the control samples. No regular pattern is shown in the test results of the phase angle. Modified asphalt mixture with 2% plastic is of the greatest dynamic modulus and phase angle.%针对目前大量废旧塑料处置问题,尝试将其用于改性沥青混合料,以探索其在道路工程中使用的可能性.采用超市废旧高密度聚乙烯购物塑料袋,将其切碎后按照2%.5%和8%的掺量制作沥青混合料试件,采用三种试验温度在六种加载频率下进行动态模量试验,与未掺加塑料混合料的相应指标进行对比.试验结果显示在各个试验温度和加载频率下,掺加塑料屑的混合料动态模量普遍提高.掺加塑料与否对相位角指标的影响未呈现一定规律.在各个试验温度和加载频率下,2%塑料掺量混合料均具有较高的动态模量和相位角.

  12. Characterization of crumbe rubber and modified asphalt from brazilian petroleum; Caracterizacao de borracha de pneu moido e de asfalto modificado oriundo de petroleo brasileiro

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Expedito F. dos; Feitosa, Judith P.A. [Ceara Univ., Fortaleza, CE (Brazil). Dept. de Quimica Organica e Inorganica]. E-mail: judith@dqoi.ufc.br, expeditoflavio@uol.com.br; Soares, Jorge B. [Ceara Univ., Fortaleza, CE (Brazil). Dept. de Engenharia de Transporte; Leite, Leni F.M. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas

    2003-07-01

    Initially it was made an evaluation of the thermal behavior, grain composition and elastomer content of a crumb rubber sample. It was verified a thermal resistance of the crumb rubber and an elastomer content ranging from 56 to 68 %. The asphalt binders were obtained from Brazilian CAP (Fazenda Alegre, State of Espirito Santo) and blended with crumb rubber from 2 to 22 %. The asphalt binder presented smaller penetration than pure CAP. The pure asphalt and binder was aged by the RTFOT system. It was observed a C=O band due oxidation. In the asphalt binder with 2 and 5 % of crumb rubber was verified a smaller effect of the oxygen than in the pure asphalt, which suggests larger aging resistance. Apparent viscosity analysis showed that the pure asphalt has a Newtonian behavior in temperature higher than 150 deg C, while a pseudoplastic behavior of the asphalt binder increases with crumb rubber concentration. (author)

  13. Modified-sulfur cements for use in concretes, flexible pavings, coatings, and grouts

    Science.gov (United States)

    McBee, W. C.; Sullivan, T. A.; Jong, B. W.

    1981-05-01

    A family of modified-sulfur cements was developed for the preparation of construction materials with improved properties. Various types of sulfur cements were prepared by reacting sulfur with mixtures of dicyclopentadiene and oligomers of cyclopentadiene. Durable cements were prepared with structural characteristics ranging from rigid to flexible. These cements were used to prepare corrosion-resistant materials for use in a wide variety of industrial applications where resistance to acidic and salt conditions is needed. These materials were prepared as rigid concretes, flexible pavings, spray coatings, and grouts. Production of modified-sulfur cements in a commercial-size plant was demonstrated.

  14. Storm Water General Permit 3 for Rock and Asphalt

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — General permit #3 for storm water discharges associated with industrial activity for Asphalt Plants, Concrete Batch Plants, Rock Crushing Plants and Construction...

  15. Research on the relationship between water stability and aggregate gradation of asphalt pavement

    OpenAIRE

    Zhao Bing; Zhao Bo

    2015-01-01

    In the early destruction of asphalt pavement, water damage is the most major form.In this paper, experimental study was conducted on the composition of asphalt concrete,Marshall specimens were made in different types of aggregate gradation with the same kind of asphalt. Water immersion tests were conducted in order to analysis the relationship between the water stability and aggregate gradation of asphalt pavement.

  16. Research on the relationship between water stability and aggregate gradation of asphalt pavement

    Directory of Open Access Journals (Sweden)

    Zhao Bing

    2015-05-01

    Full Text Available In the early destruction of asphalt pavement, water damage is the most major form.In this paper, experimental study was conducted on the composition of asphalt concrete,Marshall specimens were made in different types of aggregate gradation with the same kind of asphalt. Water immersion tests were conducted in order to analysis the relationship between the water stability and aggregate gradation of asphalt pavement.

  17. 水泥路面加铺沥青改造质量控制技术%Paving asphalt concrete pavement quality control techniques

    Institute of Scientific and Technical Information of China (English)

    王小兵

    2014-01-01

    总结归纳了旧路面病害检测的内容及方法,从施工管理角度出发,对沥青面层的加铺进行了质量控制,包括沥青、集料、设置试验段等内容,并通过平整度、渗水系数等控制掺量检验,对改造工程质量进行了检查验收。%This paper sums up the old road surface plant disease detection contents and methods, from the angle of construction management of asphalt road surface of the road to quality control, such as asphalt, aggregate, set up test section content, finally, through permeable coefficient control parameter inspection, inspection on project quality acceptance.

  18. Durability of crystalline phase in concrete microstructure modified by the mineral powders: evaluation by nanoindentation tests

    Directory of Open Access Journals (Sweden)

    Rajczakowska Magdalena

    2016-03-01

    Full Text Available This paper presents the nanoindentation investigation of the evolution of concrete microstructure modified by the Internal Crystallization Technology mineral powders. The samples under study were retrieved from a fragment of a circular concrete lining of the vertical mine shaft at a depth of approximately 1,000 m. Due to the aggressive environment and exposure to contaminated water, the internal surface of the structure was deteriorated, decreasing its strength significantly. The mineral powders were applied directly on the surface lining. The specimens were investigated one month, three months and one year after the application of the aforementioned substance in order to verify the time dependence of the strengthening processes and durability of the crystalline phase. The microstructural changes of concrete were assessed with the use of nanoindentation technique. The testing procedure involved including the previously cut specimens in the epoxy resin and grinding and polishing in order to reduce the surface roughness. As a result of the nanoindentation tests the hardness as well as Young’s modulus of the material were evaluated. The results were then compared and statistically analyzed. As a consequence, the disintegration time of the crystalline network in the pores of concrete was identified.

  19. Experimental study of the effect of the thermal conductivity of EAF slag aggregates used in asphaltic concrete of wearing courses on the durability of road pavements

    OpenAIRE

    Barra Bizinotto, Marilda; Aponte Hernández, Diego Fernando; Vázquez Ramonich, Enric; Méndez Candelario, Braulio Aquilino; Miró Recasens, José Rodrigo; Valls del Barrio, Susanna

    2017-01-01

    Electric Arc Furnace (EAF) steel slag is the basic material used to obtain good quality aggregates in different layers of road pavements. Many scientific papers have reported on the high frictional and abrasion resistance of this material. EAF slag aggregates are hard, dense, chemically stable and have good adhesion with bitumen, all characteristics related with its high alkaline character. These properties are important in hot mix asphalt for wearing courses where high wear is present and op...

  20. Application of Modified Asphalt in Permeable Asphalt Concrete%改性沥青在透水沥青混凝土中的应用

    Institute of Scientific and Technical Information of China (English)

    付春杰

    2016-01-01

    透水沥青混合料目前在国内外已经得到了广泛应用,与普通密级配沥青混合料相比,透水沥青混合料的空隙率较高,因此抗拉和抗剪强度受到一定的影响.通过试验对3种不同的沥青混合料进行抗压强度、高温稳定性、耐水稳定性和透水性能比较,结果表明将改性沥青应用到透水路面上,可以获得良好的路面性能.

  1. Improving Mechanical Properties of Polymer Modified Concrete Using Micro-Steel Fiber and Silica Fume

    Directory of Open Access Journals (Sweden)

    Muhammad Abed Attiya

    2017-03-01

    Full Text Available The use of Steel Fiber Reinforced Concrete (SFRC is to improve the structural behavior such as increasing the resistance to cracking and crack propagation. This work has been made to study the properties of polymer modified concrete when micro-steel fiber is incorporated at different volumetric percentages from 0.1 % to 2 %. Two mixes (1:1.5:2 and 1:2:4 have been used and modified with styrene butadiene rubber resin (SBR and silica fume with maintaining water cement ratio at 0.45. It has been found that increasing steel fiber content in concrete has a significant influence on the increase compressive, tensile, flexural strength, modulus of elasticity and stress- strain relationship. Flexural strength increases from 4.14 MPa (for 0% steel fiber to 11.83 MPa (for 2% steel fiber. Whereas, the modulus of elasticity is improved by about 77% (for 1:1.5:2 mixes and 91% (for 1:2:4 mixes.

  2. Asphalt World

    OpenAIRE

    Bedwell, Simon A.

    2009-01-01

    'What, in the end, makes advertisement so superior to criticism? Not what the moving red neon sign says - but the fiery pool reflecting it in the asphalt.' Benjamin, One-Way Street 'The parade has nothing to do with women, everything to do with men... Women are simply the scenery onto which men project their narcissistic fantasies.' Mulvey, Visual & Other Pleasures With invested irony, Simon Bedwell makes drip paintings from used advertising posters, in a messy conflation of a...

  3. Rheological Evaluation of Polymer Modiifed Asphalt Binders

    Institute of Scientific and Technical Information of China (English)

    WANG Lan; CHANG Chunqing

    2015-01-01

    The microstructure and dynamic rheological characteristics of asphalt containing different polymer modifiers (crumb rubber, styrene-butadiene-styrene and crumb rubber mix with styrene-butadiene-styrene) at mid and high service temperature levels were investigated by using scanning electron microscopy(SEM), dynamic shear rheometer(DSR) and repeat creep test. The main objective of the investigation was to rank the modifiers based on their effect on performance characteristics of asphalt under service conditions. To evaluate the effect of different modiifers on the viscoelastic response of asphalt, the temperature and frequency dependences of the dynamic viscoelastic properties were compared. The mid-temperature fatigue resistance and high-temperature rutting resistance of three polymer modiifed asphalts were evaluated to predict their ifeld performance in roads. Based on the current results, an improved rutting factor was proposed to determine the rutting resistance of asphalt pavements. In addition, the viscous stiffness (Gv), deifned as the reciprocal of viscous compliance, was used to evaluate the high-temperature deformation resistance of asphalt mixtures. The experimental results indicate that the asphalt containing crumb rubber only shows superior performance at mid and high service temperatures in all three modiifed asphalt binders due to the action of the crumb rubber.

  4. Effectiveness of Micro- and Nanomaterials in Asphalt Mixtures through Dynamic Modulus and Rutting Tests

    Directory of Open Access Journals (Sweden)

    Hui Yao

    2016-01-01

    Full Text Available The objectives of this research are to use micro- and nanomaterials to modify the asphalt mixture and to evaluate the mechanical performance of asphalt mixtures. These micro- and nanomaterials, including carbon microfiber, Nanomer material, nanosilica, nonmodified nanoclay, and polymer modified nanoclay, were selected to blend with the control asphalt to improve the overall performance of the modified asphalt binders and mixtures. The microstructures of original materials and asphalt binders were observed by the field emission scanning electron microscope (FE-SEM. The mixture performance tests were employed to evaluate the resistance to rutting and permanent deformation of the modified asphalt mixtures. Test results indicate that (1 the dynamic modulus of micro- and nanomodified asphalt mixtures improved significantly; (2 the rutting susceptibility of the modified asphalt mixtures was reduced significantly compared to that of the control asphalt mixture; (3 the microstructures of modified asphalt binders were different from the control asphalt, and the structures determine the improvement in the performance of modified asphalt mixtures. These results indicate that the addition of micro- and nanomaterials enhanced the rutting performance and strength of asphalt mixtures. In addition, the analysis of variance (ANOVA was used to analyze the modifying effects of micro- and nanomaterials on the performance.

  5. Effect of Modulated Coal Tar Pitch on Performance of Composite Modified Emulsified Asphalt%调制煤沥青对复合改性乳化沥青性能的影响

    Institute of Scientific and Technical Information of China (English)

    王红亮; 李其祥; 丁浩; 宋健伟; 王智勇; 伍林

    2014-01-01

    In order to improve the performance of modified emulsified asphalt,composite modified emulsified asphalt was prepared by adding modulated coal tar pitch and modified by SBS.Results showed that,with the in-crease of addition of modulated coal tar pitch,the ductility and softening point became better.After adding 20%modulated coal tar pitch,ductility increased to 30 cm,softening point increased to 70 ℃,composite modified e-mulsified asphalt had good performance in high or low temperature.Fluorescence microscopy and infrared spec-tral analysis showed that there were some chemical grafting reactions happened between SBS and asphalt mate-rials in the process of modification besides the physical modification,SBS formed network structure in asphalt material,so modification improved the bonding strength of SBS and asphalt material,and made the asphalt sys-tem more stable.%为提高复合改性乳化沥青的使用性能,采用加入调制煤沥青的方式和用 SBS改性制备复合改性乳化沥青。结果表明,随着调制煤沥青添加量的增加,复合改性乳化沥青的延度和软化点得到改善。当添加20%调制煤沥青后,延度提高至30 cm,软化点升到70℃,复合改性乳化沥青已具有良好的高低温性能。荧光显微图像和红外光谱分析表明,在改性过程中 SBS与沥青材料之间除物理改性外,还发生了某种化学接枝反应形成网络构架,从而提高了 SBS与沥青材料的结合强度,使得沥青体系更加稳定。

  6. Linking asphalt binder fatigue to asphalt mixture fatigue performance using viscoelastic continuum damage modeling

    Science.gov (United States)

    Safaei, Farinaz; Castorena, Cassie; Kim, Y. Richard

    2016-08-01

    Fatigue cracking is a major form of distress in asphalt pavements. Asphalt binder is the weakest asphalt concrete constituent and, thus, plays a critical role in determining the fatigue resistance of pavements. Therefore, the ability to characterize and model the inherent fatigue performance of an asphalt binder is a necessary first step to design mixtures and pavements that are not susceptible to premature fatigue failure. The simplified viscoelastic continuum damage (S-VECD) model has been used successfully by researchers to predict the damage evolution in asphalt mixtures for various traffic and climatic conditions using limited uniaxial test data. In this study, the S-VECD model, developed for asphalt mixtures, is adapted for asphalt binders tested under cyclic torsion in a dynamic shear rheometer. Derivation of the model framework is presented. The model is verified by producing damage characteristic curves that are both temperature- and loading history-independent based on time sweep tests, given that the effects of plasticity and adhesion loss on the material behavior are minimal. The applicability of the S-VECD model to the accelerated loading that is inherent of the linear amplitude sweep test is demonstrated, which reveals reasonable performance predictions, but with some loss in accuracy compared to time sweep tests due to the confounding effects of nonlinearity imposed by the high strain amplitudes included in the test. The asphalt binder S-VECD model is validated through comparisons to asphalt mixture S-VECD model results derived from cyclic direct tension tests and Accelerated Loading Facility performance tests. The results demonstrate good agreement between the asphalt binder and mixture test results and pavement performance, indicating that the developed model framework is able to capture the asphalt binder's contribution to mixture fatigue and pavement fatigue cracking performance.

  7. 关于沥青混凝土道面公路飞机跑道结构设计方法的分析与研究%Analysis and Research on Structure Design Method of Asphalt Concrete Pavement Airfield Runway on Highway

    Institute of Scientific and Technical Information of China (English)

    曲旭光; 王建宇

    2014-01-01

    This paper put forward a structural design method of asphalt concrete airport pavement about the airfield runway on highway,by study the structural design method of asphalt concrete pavement about the airfield runway,including structure design theories foundation,design indexes,control standard, mechanical response of the pavement and the design steps and flow-chart etc.%从公路飞机跑道沥青混凝土道面结构设计的理论基础、设计指标、控制标准、道面结构力学响应分析、设计流程及步骤等方面进行分析研究,提出了公路飞机跑道沥青混凝土道面结构设计方法。

  8. 基于常水头渗透试验的 PAC 排水和抗堵塞能力%Drain and anti-clogging ability of porous asphalt concrete based on constant head permeability experiment

    Institute of Scientific and Technical Information of China (English)

    王宏畅; 葛辉; 周明刚

    2016-01-01

    In order to clarify the drain and clogging behaviors of porous asphalts pavement, permea-bility coefficients were tested by using asphalt mixture homemade permeability testing device to sim-ulate multi-cycle drainage clogging experiment of porous asphalt concrete ( PAC) , and the fine ag-gregate with certain gradation was chosen as a plugging agent.The influences of asphalt mixture de-sign parameters such as the porosity, the normal maximum sizes of the aggregate, grading on the drain ability and anti-clogging ability of PAC were researched.The experimental results indicate that the porosity has an obvious influence on PAC drain ability and anti-clogging ability.The normal maximum size of the aggregate has an obvious influence on PAC anti-clogging ability, but no obvi-ous influence on the drain ability.PAC with the coarser graduation has a better performance on drain ability and anti-clogging ability.Asphalt type changes a little on PAC ability of drain and anti-clog-ging ability.The location of blocking occurred is concentrated on the top 40 mm of PAC-13 speci-men, fine particles with sizes of about 0.15 to 2.36 mm are the key particle size causing the clog-ging in the PAC-13 specimen.%为研究多空隙沥青路面的排水堵塞行为特性,通过自制常水头渗透测试装置,模拟多空隙沥青混合料( PAC)的循环堵塞试验,选用具有一定级配的细集料作为堵塞剂,测试其渗透系数.研究空隙率、最大公称粒径、级配类型等变化对PAC的排水及抗堵塞能力的影响规律.结果表明:PAC空隙率越大,其排水能力越强,抗堵塞的能力也越强;PAC的最大粒径变化对其排水能力没有明显的影响,但最大公称粒径较大的PAC试件抗堵塞的效果更好;与细型级配相比,粗型级配PAC的排水及抗堵塞能力更强;多孔沥青混合料PAC-13发生堵塞的位置集中在试件最上部的40 mm内,粒径为0.15~2.36 mm的颗粒则是造成混合料空隙堵塞的关键.

  9. 库什塔依水电站冬季施工的碾压式土石坝沥青混凝土心墙配合比试验研究%Experimental Study on the Mix Proportion of the Asphalt Concrete Core Wall of Rolled Earth-rock Dam in Winter Construction of Cush Kobita Bea Hydropower Station

    Institute of Scientific and Technical Information of China (English)

    张庆春

    2014-01-01

    库什塔依水电站位于寒冷地区,沥青混凝土心墙施工期较短,为加快工程施工进度,提前发挥发电效益,对其沥青混凝土心墙冬季低温施工的配合比进行了试验研究,并通过模拟试验验证了-25℃低温条件下的施工工艺。主要包括确定适合冬季低温施工的配合比,冬季施工沥青混凝土的分离度、层间结合性能、压实效果、接合面渗透性及沥青混凝土的力学特性。试验成果表明,沥青混凝土的各项性能均满足设计要求。%Cush Kobita Bea Hydropower Station is located in cold region of Xinjiang ,which leaves shorter time for the construction of asphalt concrete core wall of the rolled earth-rock dam .In order to shorten the construction time and make it possible for the station to operate in advance ,the mix propotion of asphalt concrete core wall were studied for winter low temperature construction .The construction process were simulated at -25℃ to test for resolution ,performance be-tween the layers ,compaction effect ,permeability of contact face and physical-mechanical properties of the asphalt con-crete .The results indicate that the properties of the asphalt concrete can meet the design requirements .

  10. Mechanical properties of sand modified resins used for bonding CFRP to concrete substrates

    Directory of Open Access Journals (Sweden)

    Aziz. I. Abdulla

    2016-12-01

    Full Text Available This study is an experimental investigation into the properties of adhesive before and after mixing with fine sand, and its behavior on reinforced concrete beams strengthened by CFRP to show the effects of modified adhesive on load-carrying capacity, ductility, stiffness and failure mode of the reinforced concrete beams. Compressive strength, flexural strength and the effect of high temperature on these properties were the focus of the current study in order to prove the efficiency of adding fine sand to improve adhesive properties and reduce cost. Based on the compressive and flexural tests, results indicated that the addition of sand to the adhesive improved its mechanical properties when sand is 50% of the total weight of the adhesive. However, its effect on the modulus of elasticity is minimal. Using adhesive with fine sand increased the ultimate load bearing capacity, ductility, stiffness and toughness of the reinforced concrete beams strengthened by CFRP. The ratio of the fine sand to the adhesive equal to 1 is considered the best in terms of the cost reduction, maintaining workability, as well as maintaining the mechanical properties. Lastly, the use of fine sand with adhesive ensured a significant reduction in the cost of the adhesive and increased the adhesive resistance to temperature.

  11. Surface Modification of Fire-retardant Asphalt with Silane Coupling Agent

    Institute of Scientific and Technical Information of China (English)

    CHEN Huiqiang; TANG Boming

    2012-01-01

    The theory and approach of the surface modified of asphalt fire-retardant with silane coupling agent were introduced,The optimum silane dosage was determined,and the structure and properties of the asphalt fire-retardant before and after the surface modification were characterized by infrared spectrum and thermo gravimetric analysis.The dispersion effect of asphalt fire-retardant was studied.The influence of the surface modification on the hydrophilicity and lipophilicity of the asphalt fire-retardant was analyzed.The experimental results showed that there were physical and chemical interactions between the silane coupling agent and the asphalt fire-retardant,which reduced the surface polarity of the asphalt fire retardant.The optimum silane coupling agent dosage was 0.95% of the asphalt fire retardant.The surface modification improved the thermal stability,dispersibility and lipophilicity of the asphalt fire retardant,which enhanced the compatibility between asphalt fire retardant and asphalt.

  12. Experimental research of MAC modified large stone porous asphalt mixture%MAC改性沥青大粒径透水性沥青混合料试验研究

    Institute of Scientific and Technical Information of China (English)

    王恩东; 张洪亮; 王选仓

    2008-01-01

    In order to improve the road performances of base course made of large stone porous asphalt mixture(LSPM), MAC(multigrade asphalt cement) modified asphalt was used in LSPM, the performances of matrix aphalt, MAC modified asphalt and SBS modified asphalt were compared, the material composition design, construction technology and the road performances of MAC modified LSPM, such as high-temperature stability, anti-fatigue property, permeability and anti-reflective crack property, were studied, and test roads were constructed. Test result shows that the porosity of LSPM is between 13% and 18%, its asphalt membrane is thicker than 12 μm, its modulous is between 400 and 600 MPa, the rut depth of test road opening to traffic for two years is between 4 and 8 mm. Obviously, MAC modified LSPM has better road performances. 4 tabs, 2 figs, 16 refs.%为了提高大粒径透水性沥青混合料(LSPM)基层的路用性能,以MAC改性沥青作为LSPM结合料,对MAC改性沥青、基质沥青和SBS改性沥青的性能进行了对比,提出了MAC改性沥青LSPM高温稳定性、水稳定性、抗疲劳性、渗透性、抗反射裂缝性等路用性能要求,并进行了MAC改性沥青LSPM材料组成设计、施工技术研究和试验路修筑.试验结果表明:MAC改性沥青LSPM空隙率为13%~18%,沥青膜的厚度大于12 μm,模量为400~600 MPa,试验路通车2年后车辙量在4~8 mm之间,这表明MAC改性沥青LSPM具有较高的路用性能.

  13. The methods of receiving coal water suspension and its use as the modifying additive in concrete

    Science.gov (United States)

    Buyantuyev, S. L.; Urkhanova, L. A.; Lkhasaranov, S. A.; Stebenkova, Y. Y.; Khmelev, A. B.; Kondratenko, A. S.

    2017-01-01

    Results of research of the coal water suspension (CWS) from a cake received in the electrodigit ways in the fluid environment and gas are given in article and also the possibilities of its use as the modifying additive in concrete are considered. Use of a coal cake is perspective as it is a withdrawal of the coal and concentrating enterprises and has extremely low cost. Methods of receiving CWS and possibility of formation of carbon nanomaterials (CNM) are given in their structure. Research and the analysis of a microstructure of a surface of exemplars before electrodigit processing, their element structure, dependence of durability of a cement stone on a look and quantity of an additive of CWS is conducted. For modification of cement the carbon nanomaterials received from the following exemplars of water coal suspensions were used: foams from a cake from a scrubber of the plasma modular reactor, coal water suspension from a cake from electrodigit installation. The product which can find further application for a power engineering as fuel for combustion, and also in structural materials science, in particular, as the modifying additive in concrete allows to receive these methods.

  14. Effects of parameters of asphalt concrete surfacing on mechanical property of paving layer%沥青混凝土铺装层各参数对铺装层力学性能的影响

    Institute of Scientific and Technical Information of China (English)

    钱振东; 黄卫

    2003-01-01

    The important parameters that influence the mechanical property of the paving layer on an orthotropic steel bridge deck are the paving layer thickness and modu lus of the asphalt concrete surfacing. Three important indices that control the typical failures of the paving layer are the maximum tensile stress of paving l ayer, the maximum shear stress between the steel deck and the paving layer, and the maximum deflection on the paving surface. In this paper, the analytical model of paving systems on orthotropic steel bridge deck is established, and the finite element method is adopted to study the stress and strain of paving system. With the variation of asphalt concrete modulus in high or low temperature season, the influences of paving layer thickness on three control indices are researc hed. The results provide a theoretical basis for the determination of thickness of the paving layer on the steel bridge deck.%影响正交异性钢桥面铺装层力学性能的重要参数有铺装层的厚度和沥青混凝土铺装层的模量.铺装层典型破坏的3个控制指标是铺装层的最大横向拉应力、钢板和铺装层间的最大剪切应力和铺装层的最大挠度.本文建立正交异性钢桥面铺装体系分析模型,用有限元方法进行了铺装体系的受力分析,研究在高、低温季节沥青混凝土模量变化的情况下,不同铺装层厚度对三大控制指标的影响.研究结果对钢桥面铺装层厚度的确定提供了理论依据.

  15. The Test of Adhesion between TLA Modified Asphalt with Limestone and Calcite%TLA改性沥青与石灰石、方解石的粘附性试验

    Institute of Scientific and Technical Information of China (English)

    何萍

    2012-01-01

    The paper investigated the test of adhesion between TLA modified asphalt with limestone and calcite. The results show that adhesion between TLA modified asphalt with limestone and calcite are fifth grade. Because calcite is a soft stone, the pure calcite is cleared out by hand and the content of calcite in limestone is strictly controlled in the highway construction.%TLA改性沥青与石灰岩、方解石的粘附性试验表明:TLA改性沥青与石灰岩、方解石的粘附性均为5级.方解石属于软石,对于石灰岩中纯净的方解石应通过人工挑选的方法加以清除,对于夹杂有方解石的石灰岩应严格控制石灰岩中方解石的含量.

  16. Laboratory and Field Asphalt Fatigue Performance, Matching Theory with Practice

    NARCIS (Netherlands)

    Pramesti, F.P.

    2015-01-01

    This thesis investigates the relationship between predicted and observed fatigue life of asphalt. This study also investigates the positive effects of modifying bitumen with Retona, a bitumen modifier produced in Indonesia from natural asphalt rock sources, on pavement performance in terms of increa

  17. 无机阻燃改性沥青结构表征及阻燃机理研究%Structural expressions and retarding mechanism of inorganic modified fire-retardant asphalt

    Institute of Scientific and Technical Information of China (English)

    王朝辉; 董彪; 高志伟; 刘志胜; 贺海

    2014-01-01

    Considering the problem of heavy smoke,toxic,high cost of some flame retardants,two new inorgan-ic flame retardants were developed,and the fire-retardant modified asphalts were prepared;in order to study the internal structure and the flame-retardant mechanism of our new developed flame-retardant asphalt,the combi-nation between flame retardant particles and asphalt were analyzed by scanning electron microscopy (SEM)test and the effect of the flame retardants on the functional groups was studied by infrared spectroscopy (FT-IR) test.The effect of inorganic fire-retardants on the nature of asphalt was analyzed by using TG experiment.The research results showed that the flame retardant effect of the modified asphalt was well;the inorganic fire-re-tardant modifiers can be evenly distributed in asphalt and there was no phenomenon of reunion.FT-IR test shows that there was no covalent generating when the two flame retardants are added into the asphalt.The ther-mal weightlessness of inorganic modified fire-retardant asphalt was greater than that of base asphalt.%针对目前某些阻燃剂发烟量大、有毒和成本较高问题,研发了两种新型无机阻燃剂,并制备了无机阻燃改性沥青;借助扫描电镜(SEM)实验和红外光谱(FT-IR)实验,探究了两种阻燃剂与沥青的结合状况以及二者对沥青官能团的影响;通过热重(TG)实验,分析了两种阻燃剂对沥青燃烧过程中热失重变化的影响,探究了两种阻燃改性沥青的作用机理。结果表明,两种新型无机阻燃沥青性能良好;无机阻燃剂颗粒可均匀地分布在沥青中,没有团聚现象,两种阻燃剂各颗粒与沥青具有良好的粘结性;两种新型阻燃剂加入到沥青中,未与沥青形成新的共价键;燃烧过程中无机阻燃改性沥青的热失重大于基础沥青,无机阻燃沥青主要凭借阻燃剂的结合水分挥发以及金属化合物烧结覆盖作用发挥阻燃作用。

  18. 努尔加水库碾压式土石坝沥青混凝土心墙酸性砂砾石料的配合比试验研究%Experiment on mix proportion of acidic gravel stone for asphalt concrete core wall of rolled earth rockfill dam in Nulga reservoir

    Institute of Scientific and Technical Information of China (English)

    张庆春

    2014-01-01

    努尔加水库周围天然砂砾石料丰富,而碱性岩石料源距离坝址较远,为节省工程投资,对碾压式土石坝沥青混凝土心墙采用酸性砂砾石料进行了配合比试验研究,主要包括抗剥落剂的选型和沥青混凝土的水稳定试验,并对所推荐配合比的沥青混凝土进行了压缩、拉伸、弯曲、静三轴和渗透试验。结果表明:推荐配合比的沥青混凝土其各项物理力学性能均满足设计要求。%The natural material of gravel stone around Nulga reservoir is rich but the material of rock stone is far from dam area , in order to save the engineering investment , the paper researched mix propor-tion about asphalt concrete core wall which adopted acidic gravel stone of rolled fill dam in Nulga reser -voir.The work mainly included the selection of antistripping agent and water stability test of asphalt con -crete.It also carried out compression , stretching, bending, static triaxial and penetration test for asphalt concrete of recommended mix proportion .The results show that the various physical and mechanical prop-erties of asphalt concrete of recommended mix proportion can satisfy the requirement of design .

  19. 高海拔地区碾压式沥青混凝土心墙施工技术--以旁多水利枢纽大坝为例%Construction technology of roller-compacted asphalt concrete core walls in high-altitude areas:A case study of dams in Pangduo Hydraulic Project

    Institute of Scientific and Technical Information of China (English)

    向尚君; 石林; 廖佼

    2014-01-01

    为总结碾压式沥青混凝土心墙在高海拔地区的施工经验,以首次在西藏高海拔地区应用的西藏旁多水利枢纽大坝碾压式沥青混凝土心墙施工为例,从原材料、施工机械设备、沥青混合料施工配合比、沥青混合料拌和、沥青混凝土心墙施工方法、温度控制及防护措施等方面针对制约高海拔地区碾压式沥青混凝土心墙施工的主要问题进行了总结,指出高地震烈度、强紫外线辐射、深覆盖层、高寒等地质和气候特点是制约高海拔地区碾压式沥青混凝土心墙施工的主要问题,初步探寻出了加大沥青含量提高变形能力、采用帆布覆盖措施防止紫外线辐射、采取棉被和砂砾石覆盖措施进行保温等解决方法,并在旁多水利枢纽大坝碾压式沥青混凝土心墙施工中得到成功应用。%In order to summarize the construction experience of roller-compacted asphalt concrete core walls in high-altitude areas, the construction of core walls of the dams in the Pangduo Hydraulic Project, which were first used in the high-altitude area in Tibet, was taken as an instance. The construction technology for the roller-compacted hydraulic asphalt concrete cores in high-altitude areas is discussed, including raw materials, construction machinery and equipment, the construction mixing ratio of the asphalt mixture, the mixing technology of the asphalt mixture, construction methods of asphalt concrete core walls, temperature control and protective measures. It is concluded that geological and climatic characteristics such as high seismic intensity, strong ultraviolet radiation, deep overburden, and the extremely cold climate mainly affected the construction of roller-compacted asphalt concrete core walls in high-altitude areas. Methods to solve these problems are proposed, such as improving the deformation capacity by increasing the asphalt content, preventing ultraviolet radiation by using a

  20. Evaluación de las propiedades mecánicas de una mezcla densa en caliente modificada con asfaltita/Mechanical Properties Evaluation of a hot Asphalt Mixture Modified with Asphaltite

    Directory of Open Access Journals (Sweden)

    Hugo Alexander Rondón Quintana

    2012-12-01

    Full Text Available El trabajo evaluó en laboratorio la resistencia mecánica bajo carga monotónica, el módulo resiliente y la resistencia a la deformación permanente que experimenta una mezcla asfáltica cuando se modifica con una asfaltita. Adicionalmente, fue evaluada durante dos años, la influencia del medio ambiente de la ciudad de Bogotá D.C., sobre las propiedades mecánicas de la mezcla modificada. Se concluye que la resistencia mecánica de la mezcla asfáltica modificada incrementa en comparación con la convencional. La tendencia general de las mezclas con el tiempo de exposición al medio ambiente de Bogotá D.C., es experimentar un aumento en los valores de rigidez debido principalmente a procesos de endurecimiento por envejecimiento del ligante asfáltico. Sin embargo, para el caso de las mezclas modificadas y fabricadas con CA 60-70 en los primeros cinco meses de exposición, la rigidez disminuye.The strength under monotonic load, resilient modulus and rutting were evaluated on a hot-mix asphalt (HMAmodified with a natural sphaltite. Additionally, the influence of the environmental conditions of BogotáD.C., was evaluated during two years on the mechanical properties of a modified asphalt mixture. The results show that the mechanical properties evaluated were better for the HMA mixes modified in compared with those with neat asphalts. The asphaltite produces higher mechanical resistance in HMA. The general tendency of the mixtures is increase the modulus with time due to aging of the asphalt cement. However, modified mixtures with AC 60- 70, decrease in stiffness during the first months.

  1. Application of modified-alginate encapsulated carbonate producing bacteria in concrete: a promising strategy for crack self-healing

    Directory of Open Access Journals (Sweden)

    Jianyun eWang

    2015-10-01

    Full Text Available Self-healing concrete holds promising benefits to reduce the cost for concrete maintenance and repair as cracks are autonomously repaired without any human intervention. In this study, the application of a carbonate precipitating bacterium Bacillus sphaericus was explored. Regarding the harsh condition in concrete, B. sphaericus spores were first encapsulated into a modified-alginate based hydrogel (AM-H which was proven to have a good compatibility with the bacteria and concrete regarding the influence on bacterial viability and concrete strength. Experimental results show that the spores were still viable after encapsulation. Encapsulated spores can precipitate a large amount of CaCO3 in/on the hydrogel matrix (around 70% by weight. Encapsulated B. sphaericus spores were added into mortar specimens and bacterial in-situ activity was demonstrated by the oxygen consumption on the mimicked crack surface. Specimens with free spores added showed no oxygen consumption. This indicates the efficient protection of the hydrogel for spores in concrete. To conclude, the AM-H encapsulated carbonate precipitating bacteria have great potential to be used for crack self-healing in concrete applications.

  2. Application of modified-alginate encapsulated carbonate producing bacteria in concrete: a promising strategy for crack self-healing.

    Science.gov (United States)

    Wang, Jianyun; Mignon, Arn; Snoeck, Didier; Wiktor, Virginie; Van Vliergerghe, Sandra; Boon, Nico; De Belie, Nele

    2015-01-01

    Self-healing concrete holds promising benefits to reduce the cost for concrete maintenance and repair as cracks are autonomously repaired without any human intervention. In this study, the application of a carbonate precipitating bacterium Bacillus sphaericus was explored. Regarding the harsh condition in concrete, B. sphaericus spores were first encapsulated into a modified-alginate based hydrogel (AM-H) which was proven to have a good compatibility with the bacteria and concrete regarding the influence on bacterial viability and concrete strength. Experimental results show that the spores were still viable after encapsulation. Encapsulated spores can precipitate a large amount of CaCO3 in/on the hydrogel matrix (around 70% by weight). Encapsulated B. sphaericus spores were added into mortar specimens and bacterial in situ activity was demonstrated by the oxygen consumption on the mimicked crack surface. While specimens with free spores added showed no oxygen consumption. This indicates the efficient protection of the hydrogel for spores in concrete. To conclude, the AM-H encapsulated carbonate precipitating bacteria have great potential to be used for crack self-healing in concrete applications.

  3. Properties of concrete modified with waste Low Density Polyethylene and saw dust ash

    Science.gov (United States)

    Srimanikandan, P.; Sreenath, S.

    2017-07-01

    The increase in industrialization creates need for disposal of large quantity of by-products. To overcome the difficulty of disposal, these by-products can be used as a replacement for raw material. In this concern, non-conventional industrial wastes such as plastic bags, PET bottles, pulverized waste Low Density Polyethylene (LDPE) and biological waste such as saw-dust ash, coconut coir were used as a replacement in concrete. In this project, saw-dust ash and pulverized waste LDPE were introduced as the partial replacement for cement and fine aggregates respectively. 0%, 5%, 10%, 15% and 20% of sand by volume was replaced with LDPE and 0%, 1%, 3%, 5% and 10% of cement by volume was replaced with saw dust ash. Standard cube, cylinder and prism specimens were cast to assess the compressive strength, split tensile strength and flexural strength of modified concrete after 28 days of curing. Optimum percentage of replacement was found by comparing the test results. The mix with 5% of LDPE and 3% of saw dust ash showed a better result among the other mixes.

  4. Low temperature asphalt mixtures

    OpenAIRE

    Modrijan, Damjan

    2006-01-01

    This thesis presents the problem of manufacturing and building in the asphalt mixtures produced by the classical hot procedure and the possibility of manufacturing low temperature asphalt mixtures.We will see the main advantages of low temperature asphalt mixtures prepared with bitumen with organic addition Sasobit and compare it to the classical asphalt mixtures. The advantages and disadvantages of that are valued in the practical example in the conclusion.

  5. Laboratory Investigation upon the Rheological Property of Activated Coal Gangue-modified Asphalt Binder%活化煤矸石改性沥青胶浆流变性能实验研究∗

    Institute of Scientific and Technical Information of China (English)

    杨晓凯; 熊锐; 范天奇; 杨涛; 盛燕萍

    2015-01-01

    The coal gangue is one of the greatest industrial solid waste emissions in our country at present,but few researches concentrate on using coal gangue as the filler to enhance the properties of asphalt both at home and abroad.Cone penetration test,dynamic shear rheological test (DSR)and bending beam rheological test (BBR)were adopted to investigate the high and low temperature rheological properties of the activated coal gangue-modified asphalt mortar under the condition of different filler-bitumen ratios,compared with mineral powder modified asphalt mortar. Based on that,the modification mechanism of coal gangue upon asphalt mortar was explored.The results showed that the substitution of activated coal gangue for mineral powder could make the shear strength and high temperature per-formance of asphalt mortar increase sharply,while the low temperature performance remained almost the same.The research results can provide a basis for the feasibility of substituting activated coal gangue mineral powder for common mineral powder as filling powder in asphalt mixture.%煤矸石是我国目前排放量最大的工业固体废弃物之一,以粉体煤矸石为填料对沥青进行改性在国内外鲜有研究涉及。采用锥入度实验、动态剪切流变实验(DSR)和弯曲梁流变实验(BBR),研究了不同粉胶比条件下活化煤矸石改性沥青胶浆的剪切强度及高、低温流变性能变化规律,并与矿粉改性沥青胶浆进行对比;在此基础上,初探了活化煤矸石改性沥青胶浆作用机理。结果表明,采用活化煤矸石替代矿粉后,沥青胶浆的抗剪强度和高温性能大幅提高,低温性能则基本相当。研究成果为活化煤矸石替代矿粉作为沥青混合料填料的可行性提供了依据。

  6. On application of rubber modified asphalt in heavy-loaded roadbed%橡胶改性沥青在重交通荷载路面上的应用

    Institute of Scientific and Technical Information of China (English)

    张光明

    2012-01-01

    结合已建工程实例,运用相关数据对橡胶改性沥青的优良性能进行了综合分析评价,阐述了橡胶沥青的应用工艺和施工注意事项,通过在北方低温寒冷地区重交通荷载路面上推广应用,可较好地提高路面性能与使用寿命,为国家处理"废旧轮胎污染环境"问题提供了持续性的解决方案,为发展"节约型经济"作出贡献。%Combining with the established engineering cases, the paper adopts relative data to have the comprehensive analysis evaluation of the excellent performance of the rubber modified asphalt, illustrates the application craft of the rubber asphalt and precautions in the construction, improves the road performance and lifespan by enhancing the application of the rubber modified asphalt in the heavy-loaded roadbeds in cold areas in north of China, and provides some solution to the problems of the "wasted tire pollution in environment" by national government, so as to make some contribution to the development of the "conservation-minded economy".

  7. Application of Energy Efficient Warm Mix Asphalt Concrete in Pavement Construction in Extremely Cold Areas%低能耗温拌沥青混凝土施工技术在高寒地区路面工程中的应用

    Institute of Scientific and Technical Information of China (English)

    唐忠平; 宋远慧

    2011-01-01

    温拌温铺沥青混凝土初次在青藏高原公路施工技术上的尝试和应用,克服了低温作业的影响,有效降低有害气体和粉尘颗粒排放,同时又保证了与热拌沥青混凝土基本相同的路用性能和施工和易性,为工程顺利实施赢得时间效益。%The first application of warm mix asphalt concrete in highway construction in Qinghai-Tibet Plateau overcame the impact of low temperature,reduced harmful gas and dust particles effectively and at the same time ensured the same pavement performance and construction workability with that of hot mix asphalt,which gained time efficiency for successful implementation of pavement engineering.

  8. Modified hydrotalcites as a new emerging class of smart additive of reinforced concrete for anticorrosion applications: a literature review

    NARCIS (Netherlands)

    Yang, Z.; Fischer, H.R.; Polder, R.B.

    2013-01-01

    Modified hydrotalcites (MTHs) represent a group of technologically promising materials for addition to concrete to improve its durability in aggressive environment, owing to their low cost, relative simplicity of preparation, and plenty of unique composition variables that may be adopted. Up to date

  9. Strength and durability of concrete modified by sulfur-based impregnating compounds

    OpenAIRE

    MASSALIMOV Ismail Alexandrovich; YANAKHMETOV Marat Rafisovich; CHUYKIN Alexander Eugenyevich

    2015-01-01

    The aim of the research was to determine how sulfur-containing compound impregnation influences on concrete compressive strength and the impact resistance of concrete tiles. The results of these studies indicate that impregnation of vibropressed concrete paving tiles and concrete samples of dif-ferent strength classes with aqueous solutions based on calcium polysulfide leads to a significant increase of compressive strength and impact resistance. These data show that the strength of the pr...

  10. 掺加废旧轮胎热解油的聚合物改性沥青性能研究%Performance of Polymer Modified Asphalt Mixed with Waste Tire Pyrolysis Oil

    Institute of Scientific and Technical Information of China (English)

    张跃峰

    2014-01-01

    Through vacuum pyrolysis of waste tire, two kinds of residual oil H09 and H18 can be got. Through related experiments on performance of SHRP and conventional asphalt, it can be got that adding polymer and H18 pyrolysis residue into asphalt under normal and high temperature can improve the per-formance of asphalt. Trough observing and analyzing microstructure of modified asphalt by using optical microscope, it can be got that the microphase separation effect of Ostwald ripening mechanism on discrete polymer is very small. Study finds that, the changes of polyethylene structure in the mixture are unrelated to the type of the asphalt;there are 20℃difference of the high temperature standard between SHRP sys-tem and universal law the system;the high and low temperature performance of asphalt mixture containing 10%H18 and 1%polymer is the best.%对废旧轮胎进行真空裂解,可以得到两种残留热解油H09和H18。通过SHRP以及常规沥青性能的相关试验可知,在常温和高温条件下,向沥青中加入聚合物和H18热解残留物可以改善沥青的性能。通过采用光学显微镜对改性沥青的微观结构进行观察分析,可知奥氏熟化机制对离散的聚合物产生微相分离的作用非常小。研究发现,聚乙烯结构在混合物中的变化与沥青的类型无关;SHRP体系中高温标准与环球法高温标准在系统上有20℃的差异;含10%H18和1%聚合物的沥青混合物高低温性能最好。

  11. Comparing Production and Placement of Warm-Mix Asphalt to Traditional Hot-Mix Asphalt for Constructing Airfield Pavements

    Science.gov (United States)

    2013-08-01

    pressure cells ( EPC ), single depth deflectometers (SDD), and asphalt strain gauges (ASG) are indicated by symbols denoted on the figures. Further...gauges, I-buttons, ASGs, SDDs, and EPCs to measure the pavement response to simulated aircraft loading. The asphalt concrete strain gauges (Figure 55...gauge in backscatter mode. The type of roller used for each pass is indicated on each figure. The contractor determined how many roller passes to use

  12. Numerical analysis of wetting-induced deformation of Xiyu conglomerate gravel dam with asphalt concrete core%西域砾岩砂砾料沥青混凝土心墙坝湿化变形数值分析

    Institute of Scientific and Technical Information of China (English)

    邹德高; 杨小龙; 刘京茂; 孔宪京; 周扬

    2015-01-01

    Gravel from Xiyu conglomerate, which is easily softened and disintegrated when inundated,is widely used as filling materials of dam in Xinjiang region of China.Therefore,the wetting deformation problem of earth dams during the reservoir filling is a serious concern in engineering field.The generalized plastic model and wetting model based on the wetting tests of Xiyu conglomerate gravel are incorporated into procedure, and numerical analyses of wetting-induced collapse of an asphalt concrete core dam are performed.Analytical results show that the generalized plastic model combined with the wetting model can well reflect the wetting deformation and stress distribution of the dam.Wetting collapse that happened in the upstream shell increases the horizontal displacement toward the upstream direction and settlement significantly,the maximum horizontal displacement increases from 1.5 cm to as much as 22 cm and the maximum settlement increases from 0.17% to 0.53% of the dam height,which leads to the significant deformation of the asphalt concrete core.Wetting deformation of Xiyu conglomerate gravel is apparently larger than the granite rockfill, for the maximum settlement is nearly 3 times of that of the granite rockfill.Particularly,small tensile stress is observed around the dam crest, which may result in cracks nearby. Therefore, close attention should be paid to the wetting deformation during reservoir impoundment for dams filled with Xiyu conglomerate gravel in Xinjiang arid region.%我国新疆地区广泛使用西域砾岩砂砾料作为筑坝材料,由于西域砾岩砂砾料浸水后易软化、崩解,大坝蓄水后的湿化变形分析成为工程界广泛关注的问题.联合广义塑性模型和西域砾岩砂砾料湿化模型,对某沥青混凝土心墙坝进行了湿化变形有限元分析.结果表明:广义塑性模型和西域砾岩砂砾料湿化模型能够很好地反映大坝湿化变形及应力分布规律;上游蓄

  13. Evaluation of Asphalt Concrete Pavement Based on Passenger Ride Comfort Level%基于驾乘舒适性的沥青混凝土路面评价

    Institute of Scientific and Technical Information of China (English)

    王锋; 张金喜

    2014-01-01

    In order to provide a theoretical basis for the ride comfort level evaluation, daily management,and maintenance of asphalt concrete pavement,the performance parameters and three-directional acceleration data of highway pavements were measured indoors and outdoors. Using these data,the relationship between the mean square of weighted acceleration and the pavement performance was studied. A linear regression equation that reflects the relationship between the root mean square of weighed acceleration,speed,and roughness was obtained by fitting 214 groups of experimental data. In addition,the outdoor experimental results were verified using a driving simulator. The results show that the root mean square of weighed acceleration is strongly correlated with roughness,moderately correlated with the speed,and weakly correlated with the dynamic friction coefficient. Given a certain dynamic friction coefficient,the ride comfort level of an asphalt concrete pavement reduces with its roughness and driving speed increasing. When the roughness is 1. 35 and 3. 05 mm/m,the maximum speed with an appropriate ride comfort level is 124. 1 and 88. 7 km/h,respectively.%为给沥青混凝土路面舒适性评价及日常管理养护提供理论依据,在测得室内外大量道路路面性能参数及三向加速度数据的基础上,研究了加权加速度均方根值与道路路面性能参数之间的关系.运用214组有效室外实验数据,拟合了加权加速度均方根、行驶速度与平整度关系的线性回归方程,并用驾驶模拟舱对室外实验结论进行了验证.结果表明:加权加速度均方根与平整度强相关,与速度中等程度相关,与动态摩擦系数弱相关,在动态摩擦系数一定的条件下,驾乘舒适性随平整度及行驶速度的增加而降低;当平整度为1.35和3.05 mm/m时,满足驾乘舒适性的最大速度分别为124.1和88.7 km/h.

  14. Application of Conductive Materials to Asphalt Pavement

    Directory of Open Access Journals (Sweden)

    Hai Viet Vo

    2017-01-01

    Full Text Available Snow-melting pavement technique is an advanced preservation method, which can prevent the forming of snow or ice on the pavement surface by increasing the temperature using an embedded heating system. The main scope of this study is to evaluate the impact of conductive additives on the heating efficiency. The electrical resistivity and thermal conductivity were considered to investigate effects of conductive additives, graphite, and carbon fibers on the snow-melting ability of asphalt mixtures. Also, the distribution of the conductive additives within the asphalt concrete body was investigated by microstructural imaging. An actual test was applied to simulate realistic heating for an asphalt concrete mixture. Thermal testing indicated that graphite and carbon fibers improve the snow-melting ability of asphalt mixes and their combination is more effective than when used alone. As observed in the microstructural image, carbon fibers show a long-range connecting effect among graphite conductive clusters and gather in bundles when added excessively. According to the actual test, adding the conductive additives helps improve snow-melting efficiency by shortening processing time and raising the surface temperature.

  15. Analysis of Adhesive Characteristics of Asphalt Based on Atomic Force Microscopy and Molecular Dynamics Simulation.

    Science.gov (United States)

    Xu, Meng; Yi, Junyan; Feng, Decheng; Huang, Yudong; Wang, Dongsheng

    2016-05-18

    Asphalt binder is a very important building material in infrastructure construction; it is commonly mixed with mineral aggregate and used to produce asphalt concrete. Owing to the large differences in physical and chemical properties between asphalt and aggregate, adhesive bonds play an important role in determining the performance of asphalt concrete. Although many types of adhesive bonding mechanisms have been proposed to explain the interaction forces between asphalt binder and mineral aggregate, few have been confirmed and characterized. In comparison with chemical interactions, physical adsorption has been considered to play a more important role in adhesive bonding between asphalt and mineral aggregate. In this study, the silicon tip of an atomic force microscope was used to represent silicate minerals in aggregate, and a nanoscale analysis of the characteristics of adhesive bonding between asphalt binder and the silicon tip was conducted via an atomic force microscopy (AFM) test and molecular dynamics (MD) simulations. The results of the measurements and simulations could help in better understanding of the bonding and debonding procedures in asphalt-aggregate mixtures during hot mixing and under traffic loading. MD simulations on a single molecule of a component of asphalt and monocrystalline silicon demonstrate that molecules with a higher atomic density and planar structure, such as three types of asphaltene molecules, can provide greater adhesive strength. However, regarding the real components of asphalt binder, both the MD simulations and AFM test indicate that the colloidal structural behavior of asphalt also has a large influence on the adhesion behavior between asphalt and silicon. A schematic model of the interaction between asphalt and silicon is presented, which can explain the effect of aging on the adhesion behavior of asphalt.

  16. 布敦岩沥青复合改性SMA-13混合料设计及性能%Mixture design and pavement performance for BRA compound modified asphalt mixture SMA-13

    Institute of Scientific and Technical Information of China (English)

    2016-01-01

    In order to improve the high-temperature anti-deformation capacity of SMA pavement,the Buton rock asphalt (BRA)is used as the modifier to conduct the experi-mental research on the mixture design and pavement performance of compound modified stone mastic asphalt mixture SMA-13 of BRA and SBS modified asphalt (abbrevd BSS-MA-13)with five kinds of BRA mixing amount.According to the contents of pure nat-ural asphalt and mineral in the BRA as well as the material composition of asphalt mix-ture,the calculation method of mixture ratio of BRA modified asphalt mixture is put forward to provide an analysis basis for its mixture design.The mixture design results show that the BRA can be replaced by a part of SBS modified asphalt,fine aggregate and mineral powder,but the pure natural asphalt in BRA should not be applied for e-quivalent replacement of SBS modified asphalt.The total optimum oil-stone ratio of BSSMA-13 increases slightly with the increase of BRA mixing amount,and it increases about 0.1%~0.3% in the range of BRA mixing amount 2%~5%.The pavement per-formance tests show that the incorporation of BRA can effectively improve the high-temperature stability,water stability,flexural tensile strength and bond behavior of BSSMA-13 with the favorable performances of anti-permeability and skid resistance, but it has a certain influence on the low-temperature anti-deformation capacity.Hereby, the suitable mixing amount of BRA is obtained as 3%~4%.Therefore,BRA is a kind of modifier with excellent performance,and its modified SMA-13 is suitable for the as-phalt pavement of heavy traffic road in the special road sections including bridge deck, tunnel,large longitudinal slope and bend,etc.,in southern China's rainy region.%为了提高SMA路面的高温抗变形能力,以布敦岩沥青(BRA)作为改性剂,对5种BRA掺量的BRA与SBS改性沥青复合改性沥青玛蹄脂碎石混合料SMA-13(简记为BSSMA-13)的配合比设计和路用性能进行了试验研究.根据BRA

  17. Asphalt Pavement Aging and Temperature Dependent Properties Using Functionally Graded Viscoelastic Model

    Science.gov (United States)

    Dave, Eshan V.

    2009-01-01

    Asphalt concrete pavements are inherently graded viscoelastic structures. Oxidative aging of asphalt binder and temperature cycling due to climatic conditions being the major cause of non-homogeneity. Current pavement analysis and simulation procedures dwell on the use of layered approach to account for these non-homogeneities. The conventional…

  18. Use of waste crushed glass for the production of hot-mix asphalt

    CSIR Research Space (South Africa)

    Anochie-Boateng, Joseph

    2016-08-01

    Full Text Available presents the development and evaluation of a new asphalt concrete mix that utilizes a sustainable crushed glass as a replacement material of a natural aggregate. The ultimate goal is to produce a cost-effective asphalt wearing course with comparative...

  19. 石棉尾矿酸浸渣填充改性道路沥青的研究%Research on Road Asphalt Filled and Modified with Acid-leaching Residue of Asbestos Tailings

    Institute of Scientific and Technical Information of China (English)

    孙志明; 郑水林; 文明; 吴照洋

    2009-01-01

    The acid-leaching residue of asbestos tailings is silicon slag of asbestos tailings, one kind of solid waste after acid leaching extraction of magnesium. In this experiment, using acid leaching residue of asbestos tailings after calcination as the filler of asphalt modifier, through the test of penetration, ductility, softening point of modified asphalt, the effects of the adding volume and mixing conditions (temperature, time, etc.) of the acid leaching residue on the performance of road asphalt has been studied. The results showed that the appropriate conditions of modified process is that the adding volume of acid leaching residue 6%, mixing temperature 140℃, and heating mixing time 20rain. In this condition, the performance of modified asphalt material, such as high temperature and low temperature performance, temperature sensitivity, and anti-aging property have been significantly improved.%石棉尾矿酸浸渣是石棉尾矿蛇纹石酸浸提取氧化镁后的硅质粉体材料.本实验以煅烧后的石棉尾矿酸浸渣作为道路沥青填充改性剂,通过测定改性沥青的针入度、延度、软化点等指标,研究了酸浸渣填充量、混合控温以及加热混合时间对道路沥青综合性能的影响.结果表明,石棉尾矿酸浸渣填充改性沥青适宜的填充工艺条件为填充量6%,混合控温140℃,加热混合时间20min;在适宜的填充工艺条件下,改性沥青的高温性能、低温性能、高低温稳定性以及抗老化性均得到显著改善或提高.

  20. 南京铁心桥钢桥面热拌环氧混凝土铺装工艺研究%Hot-mixing Epoxy Asphalt Concrete Pavement Technology for Steel BridgeDeck Pavement of Tiexin Bridge in Nanjing City

    Institute of Scientific and Technical Information of China (English)

    潘军; 杨文

    2016-01-01

    Based on the steel bridge deck pavement engineering of Tiexin bridge in Nanjing city,the pavement technologies of hot mixing epoxy asphalt concrete using on steel deck were studied,inclu-ding the pavement structure design,mix design,pavement performance evaluation and construction technology.The difference of pavement construction between hot mixing and warm mixing epoxy as-phalt were also introduced in this paper.Research results show that hot mixing epoxy asphalt is suit-able for steel deck pavement due to its high stability,excellent high temperature performance and con-venient workability.%结合南京铁心桥钢桥面环氧铺装实体工程,对热拌环氧沥青混凝土铺装结构形式、热拌环氧沥青性能与混合料配合比设计、路用性能评价,以及施工工艺进行了系统研究,全面比较了热、温拌环氧沥青铺装施工工艺的区别。结果表明,热拌环氧沥青混凝土具有高强度、出色的高温稳定性,以及便捷的施工可操作性,非常适用于大跨钢桥铺装工程。

  1. Early age performance of latex-modified concrete bridge deck overlays

    Science.gov (United States)

    Sujjavanich, Suvimol

    Environmental factors and physical properties of latex modified concrete (LMC) are hypothesized to contribute to early age cracking in bridge deck overlays. Cracking permits the ingress of moisture and aggressive solutions into the substrate and may contribute to other subsequent distresses. Understanding the material properties and mechanisms involved is necessary to minimize these distresses. This research consisted of a two part study: first, the development of LMC strength and fracture properties at ages ranging from 5 hours to 28 days was studied, and secondly, the effects of the environment on LMC distresses were modelled. Environmental conditions: temperature, solar energy, and wind speed were determined from weather records. A fracture mechanics based model, the Fictitious Crack Model (FCM), incorporating finite element analyses and superposition techniques was employed with material properties from the first part of study on LMC performance. Different bilinear strain softening diagrams were used to predict fracture performance at different ages. The predictions agreed well with the test data. The impacts of temperature differentials on crack development were studied. The shrinkage effect was also indirectly incorporated through the temperature analysis. The material properties study indicated significant changes in strength, deformability and fracture properties, particularly during the early age. The developments differ slightly from conventional concrete. Test results indicated a significant improvement in reducing and bridging microcracks, especially in the prepeak-load region. Fracture toughness and deformability increased significantly with time. Fracture energy varied from 2.3 to 133.1 N/m, depending on age, and to some degree, on notch depth ratio. In the second stage, the FCM provided a reasonable prediction for crack initiation and propagation when only temperature effects are of concern. Age, surface conditions and structural restraint strongly

  2. Hanford Permanent Isolation Barrier Program: Asphalt technology development

    Energy Technology Data Exchange (ETDEWEB)

    Freeman, H.D.; Romine, R.A.

    1994-11-01

    An important component of the Hanford Permanent Isolation Barrier is the use of a two-layer composite asphalt system, which provides backup water diversion capabilities if the primary capillary barrier fails to meet infiltration goals. Because of asphalt`s potential to perform to specification over the 1000-year design life criterion, a composite asphalt barrier (HMAC/fluid-applied polymer-modified asphalt) is being considered as an alternative to the bentonite clay/high density poly(ethylene) barriers for the low-permeability component of the Hanford Permanent Isolation Barrier. The feasibility of using asphalt as a long-term barrier is currently being studied. Information that must be known is the ability of asphalt to retain desirable physical properties over a period of 1000 years. This paper presents the approach for performing accelerated aging tests and evaluating the performance of samples under accelerated conditions. The results of these tests will be compared with asphalt artifact analogs and the results of modeling the degradation of the selected asphalt composite to make life-cycle predictions.

  3. Mechanism of Fume Suppression and Performance on Asphalt of Expanded Graphite for Pavement under High Temperature Condition

    Institute of Scientific and Technical Information of China (English)

    HUANG Gang; HE Zhaoyi; HUANG Yangcheng; ZHOU Chao; YUAN Xiaoya

    2014-01-01

    Fume suppression mechanisms and the effect of expanded graphite on the performance of asphalt were studied by applying infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and comprehensive thermal analysis (TG, DSC). The experimental results confirm that asphalt which is mixed with expandable graphite will expand in the process of hot mix, and the expanded graphite layer will swell by the light component in the asphalt. The light component in the asphalt and PAHs adsorption on expanded graphite surface or part of the plug in the expanded graphite layer between plates made nucleation crystallization growth. And the Van der Waals force and the bonding of the lattice can effectively restrain the asphalt fume release. Meanwhile, the expanding agent with oxidative can spread into the asphalt, leading to asphalt oxygenated and plastic abate, while the ductility decreases. Expanded graphite, SBS modifier and environment- friendly plasticizers are used to composite modified asphalt. According to asphalt fume release experiment, normal test of asphalt performance, Brookfield viscosity test, RTFOT test and asphalt mixture tests (high temperature stability, low temperature stability, water stability), it has been proven that the modified asphalt’s performance is better than that of matrix asphalt and equivalent to that of SBS modified asphalt. Furthermore, it has good fume suppression effect.

  4. Aging of Asphalt Symposium, September 17th 2014, Delft, the Netherlands

    OpenAIRE

    Erkens, S.M.J.G.; Scarpas, A.; Blab, R.; Glaser, R; Glover, C.; Oeser, M.; Porot, L.; Soenen, H.

    2015-01-01

    Technical specifications for the asphalt concrete properties are developed to be able to specify mixtures that will perform well in pavement applications. Being able to identify and determine properties related to pavement performance in practice is crucial for both road authorities and contractors, since it allows for design and risk management by determining design life times and reliability. However, the properties of Asphalt Concrete (AC) change over its lifetime and since most pavement l...

  5. Effect of the Amount of Mineral Powder on the Ultraviolet Aging Properties of Asphalt

    Directory of Open Access Journals (Sweden)

    Xiangbing Xie

    2016-01-01

    Full Text Available Mortar has an important influence on the viscosity and durability of a mixture. The effects of the amount of mineral powder in asphalt mortar on the ultraviolet (UV aging properties of asphalt were investigated by a Fourier transform infrared spectrum (FTIR, gel permeation chromatography (GPC, and dynamic shear rheometer (DSR. The FTIR results show that the UV-resistant aging ability of asphalt mortar was superior to asphalt and that the carbonyl indices of the SBS- (styrene-butadiene-styrene- asphalt mortar and matrix asphalt mortar were more significant. The GPC results show that the molecular weight distribution coefficient (Mw/Mn of the SBS-asphalt-filler mastic is 1.0 and that of the matrix asphalt-filler mastic is 1.2, which is the largest. The macro-property is the most stable. The DSR results show that the matrix asphalt-filler mastic ranging from 1.0 to 1.2 and the SBS-modified asphalt-filler mastic ranging from 0.8 to 1.0 show the best UV aging resistance. Therefore, the effects of the amount of mineral powder cannot be ignored, suggesting that the best mass ratio of the matrix asphalt mortar is 1.2 and that of the SBS-modified asphalt mortar is 1.0 during the UV aging process.

  6. Strength and durability of concrete modified by sulfur-based impregnating compounds

    Directory of Open Access Journals (Sweden)

    MASSALIMOV Ismail Alexandrovich

    2015-06-01

    Full Text Available The aim of the research was to determine how sulfur-containing compound impregnation influences on concrete compressive strength and the impact resistance of concrete tiles. The results of these studies indicate that impregnation of vibropressed concrete paving tiles and concrete samples of dif-ferent strength classes with aqueous solutions based on calcium polysulfide leads to a significant increase of compressive strength and impact resistance. These data show that the strength of the products can be controlled by varying duration and frequency of the impregnation and by using pre-vacuum method. Impregnation with a solution of calcium polysulfide density of 1,23 g/cm³ can be recommended to increase strength of concrete products that are exposed to intense hydration and mechanical stress.

  7. Mechanical Behavior of Concrete Modified by Replacement of Cement by Rice Husk Ash

    Directory of Open Access Journals (Sweden)

    M.M. Saravanan

    Full Text Available ABSTRACT Construction industry is in need of lump sum quantities of materials which has increased both their demand and price. The use of large quantities of cement leads to increasing CO2 emission and as a consequence, the greenhouse effect. Consumption of wastes and byproducts from various sources in the manufacture of concrete has gained a great deal of importance in present days. Various researches are currently being conducted concerning the use of such products in concrete. RHA is a carbon neutral green product. Lots of ways are being thought of for disposing them by making commercial use of this. Rice husk ash is a good super-pozzolan which can be used to make special concrete mixes. The rice husk ash has been taken for this present study due to its easy availability and effective pozzolonic properties that are expected to improve the mechanical strength properties of concrete. Concrete specimens were made for evaluation of Compressive, Split Tensile, Flexural strength and Stress-Strain Behavior of concrete. The tests were conducted at the age of 7 and 28 days. Generally all mixes containing RHA achieved better properties than the conventional mix without RHA. By the experimental investigation the recommendation is given for using optimum percentage of RHA in concrete.

  8. Rutting Resistance of Asphalt Overlay with Multilayer Wheel Tracking Test

    Institute of Scientific and Technical Information of China (English)

    LIAO Weidong; CHEN Zheng; WU Shaopeng; MO Liantong; LIU Gang

    2006-01-01

    The rutting resistance of multilayer asphalt overlay was researched by using laboratory wheel tracking test. The effects of loading level and test temperature on rutting resistance of asphalt overlay structure were evaluated by means of multilayer specimens .In comparison with multilayer tests, standard specimens of various layers were also conducted to evaluate the rutting resistance. Experimental results indicated that the test temperature and applied load have a significant effect on rutting resistance of asphalt concrete. Higher test temperature and heavier applied load resulted in higher rut depths. In addition, the mutilayer wheel tracking test has been demonstrated to be a more reasonable solution in evaluation on rutting resistance of asphatt pavement structure beasuse it reflects the cumulative permanent deformation in all of asphalt layers.

  9. Effects of Material Parameters of Asphalt Concrete Core Wall Dam on the Working Conditions of Core Wall%土石坝沥青混凝土心墙材料参数对其工作性状的影响

    Institute of Scientific and Technical Information of China (English)

    王建祥; 唐新军; 凤炜

    2013-01-01

    During the design of asphalt concrete core wall dam,the test and design were closely linked as the calculation considering all parameters was used to guide the test and then to adjust and optimize the mix ratio design,therefore achieving the better working conditions for the dam.In this study,an asphalt concrete core wall dam in Xinjiang was used as the example.Each part of the dam was examined by the triaxial tests to obtain the parameters for the Duncan-Chang E—u model.Moreover,the Asphalt concrete core wall dam was analyzed using the three-dimensional non-linear finite element method.Based on the temperature control parameters reduction method,the effects of Duncan-Chang E-u model parameters on the maximum horizontal and vertical displacements,and the major and minor principal stresses of the asphalt concrete core wall were investigated.The results showed that the cohesion c,internal friction Angle (),and the parameters k and G have larger impacts on the maximum horizontal and vertical displacements and the major principal stress of core wall,but insignificant impacts on the minor principal stress.Additionally,other parameters had slight impacts on the maximum displacement,and the major and minor principal stresses.The results can provide the basis and reference for the optimization design and numerical calculation of mix ratio between asphalt and concrete.%在沥青混凝土心墙坝的设计中,应将试验和设计紧密相连,综合考虑各参数的影响,利用计算来指导试验,调整优化配合比设计,使大坝达到较佳的工作状态.针对新疆某沥青混凝土心墙坝,对坝体的各部分材料进行了三轴试验,得到邓肯-张E-u模型参数,并对沥青混凝土心墙坝进行三维非线性有限元分析.根据温控参数折减法,研究了邓肯-张E-u模型参数对沥青混凝土心墙的最大水平、竖向位移及大、小主应力的影响.结果表明:黏聚力c、内摩擦角φ、参数k和G对心墙的最大水平

  10. Mechanical evaluation of asphalt-aggregate mixtures prepared with fly ash as a filler replacement

    Energy Technology Data Exchange (ETDEWEB)

    Tapkin, T. [Anadolu Univ., Eskisehir (Turkey). Dept. of Civil Engineering

    2008-01-15

    This paper examined methods of introducing fly ash waste products as a filler in asphalt concrete mixtures. A literature review of studies involving fly ash and asphalts was conducted. The effect of fly ash filler replacements on the mechanical properties of asphalt-aggregate mixtures was investigated. A dense bituminous calcareous aggregate was used as a reference mixture for a series of tests. Three types of fly ash were investigated, notably (1) portland cement; (2) lime; and (3) control specimens. Changes in elastic strain, elastic modulus, and permanent strain properties of the asphalt mixtures were determined through a series of fatigue tests. The behaviour of the asphalt concrete pavements were analyzed under applied loads. Results of the tests showed that the fatigue life of the fly ash specimens was higher than the calcareous aggregate specimens. It was concluded that fly ash can used as a filler replacement for dense-graded wearing courses. 35 refs., 17 tabs., 8 figs.

  11. Characterization of asphalt materials containing bio oil from michigan wood

    Science.gov (United States)

    Mills-Beale, Julian

    The objective of this research is to develop sustainable wood-blend bioasphalt and characterize the atomic, molecular and bulk-scale behavior necessary to produce advanced asphalt paving mixtures. Bioasphalt was manufactured from Aspen, Basswood, Red Maple, Balsam, Maple, Pine, Beech and Magnolia wood via a 25 KWt fast-pyrolysis plant at 500 °C and refined into two distinct end forms - non-treated (5.54% moisture) and treated bioasphalt (1% moisture). Michigan petroleum-based asphalt, Performance Grade (PG) 58-28 was modified with 2, 5 and 10% of the bioasphalt by weight of base asphalt and characterized with the gas chromatography-mass spectroscopy (GC-MS), Fourier Transform Infra-red (FTIR) spectroscopy and the automated flocculation titrimetry techniques. The GC-MS method was used to characterize the Carbon-Hydrogen-Nitrogen (CHN) elemental ratio whiles the FTIR and the AFT were used to characterize the oxidative aging performance and the solubility parameters, respectively. For rheological characterization, the rotational viscosity, dynamic shear modulus and flexural bending methods are used in evaluating the low, intermediate and high temperature performance of the bio-modified asphalt materials. 54 5E3 (maximum of 3 million expected equivalent standard axle traffic loads) asphalt paving mixes were then prepared and characterized to investigate their laboratory permanent deformation, dynamic mix stiffness, moisture susceptibility, workability and constructability performance. From the research investigations, it was concluded that: 1) levo, 2, 6 dimethoxyphenol, 2 methoxy 4 vinylphenol, 2 methyl 1-2 cyclopentandione and 4-allyl-2, 6 dimetoxyphenol are the dominant chemical functional groups; 2) bioasphalt increases the viscosity and dynamic shear modulus of traditional asphalt binders; 3) Bio-modified petroleum asphalt can provide low-temperature cracking resistance benefits at -18 °C but is susceptible to cracking at -24 °C; 3) Carbonyl and sulphoxide

  12. Asphalt in Pavement Maintenance.

    Science.gov (United States)

    Asphalt Inst., College Park, MD.

    Maintenance methods that can be used equally well in all regions of the country have been developed for the use of asphalt in pavement maintenance. Specific information covering methods, equipment and terminology that applies to the use of asphalt in the maintenance of all types of pavement structures, including shoulders, is provided. In many…

  13. The effect of aggregate density on pavement performance of SMA-13 asphalt mixture

    Directory of Open Access Journals (Sweden)

    Qiao Yinping

    2016-05-01

    Full Text Available This paper chooses the top layer SMA-13 asphalt mixture material as the research object. Basalt was selected as pavement material, and modified SBS asphalt was used as a cementing material. Two basalt aggregates with different densities were used to carry out standard Marshall test in the laboratory.Aimed at the volume parameters of the asphalt mixture carry on anaiysis,and obtian the effect of aggregate density on pavement performance of SMA-13 asphalt mixture, which is that the density of aggregate has a significant effect on the void ratio, saturation, and the gap rate of the aggregate, thus affecting the pavement performance of the asphalt mixture

  14. Development of modified adhesives for bond between CFRP and concrete subjected to harsh environmental conditions

    OpenAIRE

    Al-Safy, Rawaa

    2017-01-01

    The attractive properties of carbon fibre reinforced polymers (CFRPs) have made such composites effective materials to use for the rehabilitation and strengthening of existing concrete structures. The wet-lay up method is the most commonly used installation technique for CFRP applications due to its many advantages, including flexibility in coping with different geometries. CF fabrics are adhesively saturated and glued to the concrete structure. The adhesive in the strengthening system transf...

  15. Effect of ageing on fatigue properties of asphalt

    Institute of Scientific and Technical Information of China (English)

    王佶; 庞凌; 吴少鹏; 刘全涛; 陈筝

    2008-01-01

    The fatigue properties of asphalts were investigated after various laboratory simulation ageing tests and outdoor natural exposure ultraviolet radiation ageing,by dynamic shear rheometer(DSR) time sweep fatigue test in constant strain model and a new type of specimen which was introduced to avoid the problem of adhesion failure between rotor and asphalt binder.The results show that outdoor natural exposure ageing(NEA) causes the decrease of retained fatigue life distinctly,and photodegradation caused by outdoor NEA of 1 250 μm thin films asphalt for three months,is found to be severer than pressure ageing vessel(PAV) with respects to retained fatigue life.The effect of photodegradation increases as the time of outdoor NEA increases.DSR time sweep fatigue test in constant strain indicates that the aged styrene-butadiene-styrene(SBS) modified asphalt still displays better fatigue properties than the corresponding base asphalt after ageing.

  16. Direct tensile test to assess healing in asphalt

    NARCIS (Netherlands)

    Leegwater, G.A.; Scarpas, T.; Erkens, S.

    2016-01-01

    Asphalt concrete has the advantageous ability to heal. During rest periods, damage present in the material is restored to a certain extent. Healing of the material can be observed in its regaining of strength and stiffness after rest periods. In this paper, a new test method is presented. It was

  17. Preparation and characterization of epoxy asphalt binder for pavement of steel deck bridge%钢箱梁桥铺装用环氧沥青材料制备和表征

    Institute of Scientific and Technical Information of China (English)

    陈志明; 亢阳; 闵召辉; 黄卫

    2006-01-01

    制备两组分的热固性环氧沥青,其中一个组分是顺酐化沥青、环氧树脂的固化剂和促进剂,另外一个组分是环氧树脂.分别使用Brookfild粘度计、拉伸实验和MTS研究了沥青的铺装适用性和混凝土性能.结果表明:尽管加入的顺酐仅有50%~60%与基础沥青发生了反应,但是与未对沥青进行顺酐化比较,其固化速率、断裂延伸率和抗拉强度等都有显著的提高.4%顺酐改性的沥青和固化剂结合与环氧树脂固化后具有平均断裂延伸率281.9%,平均强度2.63 MPa,固化混凝土的Marshell稳定度37.0 kN,未固化混凝土的Marshell稳定度10.2 kN,耐疲劳实验1 200万次试件无破坏.%A kind of thermosetting asphalt binder designated as epoxy asphalt, which is composed of two components: maleated asphalt with curing agents and accelerant of epoxy resin and epoxy resin, was prepared.Its paving feasibility and concrete performances were investigated using Brookfield viscosimeter, direct tensile test (DTT), Marshall testing and the MTS 810 hydraulic servos-system, respectively. Although only 50% to 60% of added maleic anhydride (MAH) reacted with the base asphalt irreversibly (probably by Diels-Alder mechanism), the curing rate, rupture elongation and tensile strength of maleated epoxy asphalt were enhanced more evidently than those of unmaleated epoxy asphalt. As a result, an epoxy asphalt made from 4% MAH modified asphalt and other curing agents was featured to have an average rupture elongation of 281.9%, an average tensile strength of 2. 63 MPa, and the Marshall stability of its cured concrete reached 37.0 kN, while that of uncured concrete was 10. 2 kN and the combined beam of fatigue test was still found to behave well after 12 × 106 cycles load.

  18. Application of a bio-binder as a rejuvenator for wet processed asphalt shingles in pavement construction

    OpenAIRE

    2015-01-01

    This paper investigates the merits of application of bio-binder to enhance rheological properties of asphalt binder in the presence of wet processed recycled asphalt shingles (RAS). It will further examine the performance and workability of asphalt designed with and without a specified percentage of a bio-binder produced from swine manure and RAS. Bio-binder was introduced to liquid asphalt binder modified with four different percentages of RAS; the high and low temperature properties of each...

  19. First Observation of the Blending Zone Morphology at the Interface of Reclaimed Asphalt Binder and Virgin Bitumen

    NARCIS (Netherlands)

    Nahar, S.N.; Mohajeri, M.; Schmets, A.J.M.; Scarpas, T.; Van de Ven, M.F.C.; Schitter, G.

    2013-01-01

    One of the challenges in designing recycled asphalt mixtures with a high amount of RAP is to estimate the blending degree between RAP binder and the added virgin bitumen. The extent of blending is crucial in this case as asphalt concrete response is influenced by the final binder properties. This pa

  20. 盐冻循环对胶粉改性沥青混合料性能的影响%The Influence that Salt Freezing Cycles have on the Property of Rubber Powder Modified Asphalt Mixture

    Institute of Scientific and Technical Information of China (English)

    冯蕾; 王乐; 崔亚楠; 韩吉伟; 阴福

    2014-01-01

    In winter of cold region,pavements are easily frozen by snow and ice and deicing salt is often used for to melt ice.However,the use of deicing salt can produce erosion of pavement materials.In this article,the freeze-thaw cycle test was conducted to analysis the influence that salt freeze-thaw cycles had on porosity of rubber powder modified asphalt mixture.Temperature,concentration of deicing salt and the number of freeze-thaw cycles were considered in the test.The test was carried out in accordance with the orthogonal principle.The porosity and splitting strength of the specimens were got during the test.It was found that with the increase of salt concentration and the freeze-thaw cycles,porosity of rubber pow-der modified asphalt mixture increased gradually.It showed that deicing salt causes serious damage to the rubber powder modified asphalt of pavement and it is unfavorable to use in a large amount.%冬季寒冷地区路面易积雪结冰,常使用除冰盐进行融雪除冰。除冰盐的使用会对路面材料产生侵蚀。本文通过室内冻融循环试验分析盐冻融循环对胶粉改性沥青混合料的性能的影响。实验中考虑了温度、除冰盐浓度和冻融循环次数三个因素,按照正交原理进行试验,试验测得了试件的孔隙率和劈裂强度。经分析发现,随着盐浓度和冻融循环次数的增加,胶粉改性沥青混合料的孔隙率逐渐变大。说明冬季路面使用的除冰盐对胶粉改性沥青的破坏较严重,不宜大量使用。

  1. NANOMODIFIED CONCRETE

    Directory of Open Access Journals (Sweden)

    B. M. Khroustalev

    2015-01-01

    Full Text Available One of the main directions in construction material science is the development of  next generation concrete that is ultra-dense, high-strength, ultra-porous, high heat efficient, extra corrosion-resistant. Selection of such direction is caused by extreme operational impacts on the concrete, namely: continuously increasing load on the concrete and various dynamics of such loads; the necessity in operation of concrete products in a wide temperature range and their exposure to various chemical and physical effects.The next generation concrete represents high-tech concrete mixtures with additives that takes on and retain the required properties when hardening and being used under any operational conditions. A differential characteristic of the next generation concrete is its complexity that presumes usage of various mineral dispersed components, two- and three fractional fine and coarse aggregates, complex chemical additives, combinations of polymer and iron reinforcement.Design strength and performance properties level of the next generation concrete is achieved by high-quality selection of the composition, proper selection of manufacturing techniques, concrete curing, bringing the quality of concrete items to the required level of technical condition during the operational phase. However, directed formation of its structure is necessary in order to obtain high-tech concrete.Along with the traditional methods for regulation of the next generation concrete structure, modification of concrete while using silica nanoparticles is also considered as a perspective one because the concrete patterning occurs due to introduction of a binder in a mineral matrix. Due to this it is possible to obtain nano-modified materials with completely new properties.The main problem with the creation of nano-modified concrete is a uniform distribution of nano-materials in the volume of the cement matrix which is particularly important in the cases of adding a modifier in

  2. Modified Hydrotalcites as Smart Additives for Improved Corrosion Protection of Reinforced Concrete

    NARCIS (Netherlands)

    Yang, Z.

    2015-01-01

    Corrosion of reinforcing steel is a major culprit to durability and serviceability of concrete structures. This problem is highly relevant for civil engineering structures in the transport sector, such as bridges, tunnels, harbour quays and parking structures. The dominant aggressive external influe

  3. Recent advances on self healing of concrete

    NARCIS (Netherlands)

    Schlangen, H.E.J.G.; Jonkers, H.M.; Qian, S.; Garcia, A.

    2010-01-01

    In this paper an overview is given of new developments obtained in research on self healing of cracks in cement based materials and asphalt concrete. At Delft University various projects are running to study self healing mechanisms. The first project that is discussed is Bacterial Concrete, in which

  4. Application of Common Mid-Point Method to Estimate Asphalt

    Science.gov (United States)

    Zhao, Shan; Al-Aadi, Imad

    2015-04-01

    3-D radar is a multi-array stepped-frequency ground penetration radar (GPR) that can measure at a very close sampling interval in both in-line and cross-line directions. Constructing asphalt layers in accordance with specified thicknesses is crucial for pavement structure capacity and pavement performance. Common mid-point method (CMP) is a multi-offset measurement method that can improve the accuracy of the asphalt layer thickness estimation. In this study, the viability of using 3-D radar to predict asphalt concrete pavement thickness with an extended CMP method was investigated. GPR signals were collected on asphalt pavements with various thicknesses. Time domain resolution of the 3-D radar was improved by applying zero-padding technique in the frequency domain. The performance of the 3-D radar was then compared to that of the air-coupled horn antenna. The study concluded that 3-D radar can be used to predict asphalt layer thickness using CMP method accurately when the layer thickness is larger than 0.13m. The lack of time domain resolution of 3-D radar can be solved by frequency zero-padding. Keywords: asphalt pavement thickness, 3-D Radar, stepped-frequency, common mid-point method, zero padding.

  5. Rheological properties of asphalt mixtures containing various fibers

    Institute of Scientific and Technical Information of China (English)

    叶群山; 吴少鹏; 陈筝; 刘至飞

    2008-01-01

    Rheological characteristics of fiber-modified asphalt mixture were investigated.Cellulous fiber,polyester fiber and mineral fiber were used as additives for asphalt mixture,and the dosages were 0.3%,0.3%,0.4%,respectively.Dynamic modulus test using superpave simple performance tester(SPT) was adopted to study the dynamic modulus and phase angle for the control mixture and fiber-modified ones at various temperatures and frequencies.Test results show that the rheological properties can be improved significantly by the addition of various fibers.The dynamic modulus increases with the increase of frequency,and the phase angle decreases with the increase of frequency.When various fibers are used,the dynamic modulus increases and phase angle decreases at each frequency.This indicates that the stiffness and the elastic portion of fiber-modified asphalt mixtures can be enhanced when various fibers are used,which results in the change of viscoelastic properties of mixtures.The creep test results show that the total strain and the permanent strain of asphalt mixtures during load-unload cycle can be significantly reduced,which results in the improvement of resistance to permanent deformation for asphalt mixtures containing various fiber additives.The Burgers model can be employed effectively to illustrate the rheological properties of fiber modified asphalt mixtures.

  6. Application of modified polypropylene (crude) fibers concrete to strengthen the support structures in deep mine roadway

    Institute of Scientific and Technical Information of China (English)

    BI Yuan-zhi; ZHANG Da-lin; HU Jin-hua

    2012-01-01

    The an thors developed a new composite cement base material by mixing the high tenacity polypropylene (coarse) fiber in plain cement base for the cement-layer-spray technology.By studying the key parameters of the fiber dosage,the spray layer thickness,and the fiber reinforced concrete injection time,etc.It is found that the ideal volume ratio of polypropylene (crude) fiber is 0.8% (V/V),and the secondary lining fiber concrete spraying should start when the shrinkage rate is lower than 0.5 mm/d,and the optimal thickness of shotcrete is 120 mm.The supporting effects and the economic benefits were studied using a real project practice,and the result obtained can be a good reference for practical applications of this new supporting material in the future.

  7. USE OF CRUMB RUBBER FROM USED CAR TIRES IN MINERAL ASPHALT MIXES

    Directory of Open Access Journals (Sweden)

    Andrzej Plewa

    2014-11-01

    Full Text Available With the development of the automotive industry the disposal of used tires is constantly growing problem. Storage of waste rubber is associated with a very long period of decomposition of rubber in the natural conditions. Simultaneously new technologies are developed every year, which in the future may significantly promote recycling of this type of materials. The crumb rubbery modification of the road bitumen is the one of the environmentally safe solutions of rubbery decomposition. Improvement of resistance of the crumb rubbery modification of the road asphalt mixtures is the very important ecological aspect of the future. The article presents the results of research on the fatigue life resistance of asphalt concretes AC16P and AC22P with asphalt-rubber binders. The above analyses have been based on the results of tests of fatigue life of mineral-rubber-asphalt mixes determined by the method of prismatic four-point bending (4PB-PR. Mineral-rubber -asphalt mixes have been diversified according to the amount of the additive of rubber fines in asphalt-rubber binder. On the basis of the test results have been proven improvements functional properties mineral-rubber-asphalt mixes compared with mineral-asphalt mixes with unmodified asphalt.

  8. 绿色环保型高性能沥青混凝土排水铺装用防水材料应用研究%Application research on the green high-performance waterproof material for asphalt concrete drainage pavement

    Institute of Scientific and Technical Information of China (English)

    杨冲; 冉千平; 孙德文

    2013-01-01

    This article introduces a high-performance resin-based waterproof materials for drainage pavement with asphalt con-crete,and its performance advantages as waterproof layer. Its excellent performance includes:4.07 MPa of adhesion to asphalt concrete base surface, 3.51 MPa of adhesion to the concrete surface, low temperature flexibility of up to -20℃,no impervious after 24 h under 1.8 MPa pressure, excellent abrasion resistance. It can not only achieve good compatibility between the waterproof layer with the substrate, but also avoid the economic losses due to performance deficiencies in the waterproof layer exist in the real project.%介绍了一种沥青混凝土排水铺装用的高性能树脂型防水材料以及其作为防水层所具备的性能优势.其优异性能表现在与沥青混凝土基面的粘结强度达4.07 MPa,与混凝土基面的粘结强度达3.51 MPa,低温弯折性可达-20℃,同时在1.8 MPa的压力下24 h不透水,耐磨性优良.不仅能够实现防水层与基层之间良好的相容性,同时避免了在实际工程中存在的因防水层性能缺陷带来的经济损失.

  9. Effects of Fibers on the Dynamic Properties of Asphalt Mixtures

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The dynamic characteristics of fiber-modified asphalt mixture were investigated. Cellulose fiber, polyester fiber and mineral fiber were used as additives for asphalt mixture, and the dosage was 0.3%, 0.3%,0.4%, respectively. Dynamic modulus test using SuperPave simple performance tester (SPT) was conducted to study the dynamic modulus (E*) and phase angle (δ) for the control asphalt mixture and fiber-modified ones at various temperatures and frequencies. Experimental results show that all fiber-modified asphalt mixtures have higher dynamic modulus compared with control mixture. The dynamic modulus master curves of each type of asphalt mixtures are determined based on nonlinear least square regression in accordance with the timetemperature superposition theory at a control temperature (21.1 ℃). The fatigue parameter E*×sinδ and rutting parameter E*/sinδ of asphalt mixture are adopted to study the fatigue and rutting-resistance properties, and experimental results indicate that such properties can be improved by fiber additives.

  10. Effect of fiber types on relevant properties of porous asphalt

    Institute of Scientific and Technical Information of China (English)

    WU Shao-peng; LIU Gang; MO Lian-tong; CHEN Zheng; YE Qun-shan

    2006-01-01

    The research was conducted to evaluate the effects of cellulose and polyester fibers on the properties of porous asphalt mixes,using the tests of draindown,abrasion,volumetric properties,rutting,and moisture damage. Images of scanning electron microscopy and X-ray computerized tomography were adopted to identify the microstructure of the fiber and inner stone skeleton of porous asphalt. The influence of rutting parameter (G*/sinδ) of asphalt modified by different fibers on the rutting resistance of the mixes was investigated. Based upon Mohr-Coulomb theory,the cohesion and the angle of internal friction of the mixes were derived from both indirect tension and unconfined compression strength. The experimental results indicate that fibers mainly stabilize asphalt binder and thicken asphalt film around aggregates. Furthermore,they result in the improved mechanical strength of porous asphalt mixes at high temperature slightly. From comparison analysis,cellulose fibers appear to perform better than polyester fibers in porous asphalt mixes.

  11. STATE OF TRANSPORT PROCESSES FOR REPAIRING AND ASPHALTING OF ASPHALT ROADS AND WAYS THEIR DEVELOPMENT

    Directory of Open Access Journals (Sweden)

    Nikolaev N. N.

    2015-04-01

    Full Text Available The article explains the importance of the transport process when performing repair jobs of asphalt roads. The scheme of the technological process was drawn up; job steps were identified, while the latter may be characterized by non-productive downtime of transport as well as that one of technological machines. We have analyzed the following steps of the flowchart of the road concrete mix transportation: the preparation of the road concrete mix for transportation, loading, transportation, unloading, laying and packing. The transportation of goods starts at the working site of their production and ends at the site of their consumption. The transportation process is a multistep and multioperational process having the greater diversity of technological, operational and economic operations, which must be correctly organized. It is extremely important to deliver the road concrete mix of coating plant (OP just in time, while avoiding the unproductive idle standing of the equipment, the deterioration of the mixture, as well as performing the job steps at minimum transportation cost savings. The successful combining of the steps of the concept organization of the road concrete mix transportation (coating plant, asphalt laying step, transportation step will improve the performance and will provide the reduction of the job cost. One must perform the coordination of job steps on different road sections using information technologies and communication facility

  12. Effect of rapid set binder on early strength and permeability of HES latex modified road repair pre-packed concrete

    Science.gov (United States)

    Han, J. W.; Lee, S. K.; Yu, C.; Park, C. G.

    2015-12-01

    The early strength development characteristics and permeability resistance of high early strength (HES) pre-packed road repair concrete incorporating a rapid-set binder material were evaluated for emergency repairs to road pavement. The rapid-set binder is a mixture of rapid-set cement and silica sands whose fluidity improves with the addition of styrene butadiene latex (latex). The resulting mixture has a compressive strength of 21 MPa or higher and a flexural strength of greater than 3.5 MPa after 4 hours, the maximum curing age allowed for emergency repair materials. This study examines the strength development properties and permeability resistance of HES latex-modified pre-packed road repair concrete using a rapid- set binder as a function of the latex-to-binder mixing ratio at values of 0.40, 0.33, 0.29 and 0.25. Both early strength development properties and permeability resistance increased as the ratio of latex to rapid-set binder decreased. The mixture showed a compressive strength of 21 MPa or higher after 4 hours, which is the design standard of emergency repair concrete, only when this ratio was 0.29 or lower. A flexural strength of 3.5 MPa or greater was observed after hours only when this ratio was 0.33 or lower. The standard for permeability resistance, less than 2,000 C of chloride after 7 days of curing, was satisfied by all ratios. The ratio of latex to rapid-set binder satisfying all of the conditions for an emergency road repair material was 0.29 or less.

  13. A Modified Model for Deflection Calculation of Reinforced Concrete Beam with Deformed GFRP Rebar

    Directory of Open Access Journals (Sweden)

    Minkwan Ju

    2016-01-01

    Full Text Available The authors carried out experimental and analytical research to evaluate the flexural capacity and the moment-deflection relationship of concrete beams reinforced with GFRP bars. The proposed model to predict the effective moment of inertia for R/C beam with GFRP bars was developed empirically, based on Branson’s equation to have better accuracy and a familiar approach to a structural engineer. For better prediction of the moment-deflection relationship until the ultimate strength is reached, a nonlinear parameter (k was also considered. This parameter was introduced to reduce the effect of the cracked moment of inertia for the reinforced concrete member, including a lower reinforcement ratio and modulus of elasticity of the GFRP bar. In a comparative study using six equations suggested by others, the proposed model showed better agreement with the experimental test results. It was confirmed that the empirical modification based on Branson’s equation was valid for predicting the effective moment of inertia of R/C beams with GFRP bar in this study. To evaluate the generality of the proposed model, a comparative study using previous test results from the literature and the results from this study was carried out. It was found that the proposed model had better accuracy and was a familiar approach to structural engineers to predict and evaluate the deflection behavior.

  14. Aminobenzoate modified hydrotalcites as a novel smart additive of reinforced concrete for anticorrosion applications

    NARCIS (Netherlands)

    Yang, Z.; Fischer, H.R.; Polder, R.B.

    2012-01-01

    A carbonate form of Mg-Al-hydrotalcite with Mg/Al = 2 and its p-aminobenzoate (pAB) modified derivative have been synthesized and characterized by means of XRD, IR and TG/DSC. Mg(2) Al-CO 3 was prepared by a coprecipitation method and was subsequently modified by pAB through the calcination-rehydrat

  15. A feasibility study of anticorrosion applications of modified hydrotalcites in reinforced concrete

    NARCIS (Netherlands)

    Yang, Z.; Fischer, H.; Polder, R.B.

    2012-01-01

    A carbonate form of Mg-Al-hydrotalcite with Mg/Al =2 and its p-aminobenzoate (pAB) modified derivative were synthesized and characterized by means of XRD, IR and TG/DSC. Mg(2)Al-CO3 was prepared by a coprecipitation method and was subsequently modified by pAB through the calcination-rehydration tech

  16. Development of asphaltic mix with waste products use

    Directory of Open Access Journals (Sweden)

    Pugin Konstantin Georgievich

    2014-07-01

    Full Text Available The trend of high growth of the vehicle fleet in Russia along with the positive impact on the socio-economic development of the country has a number of adverse consequences, one of which is the high accident rate on the roads. The paper considers modern way to provide the safe vehicles flow with the use of colored asphalt, which is a kind of hot asphalt and can have a variety of colors, which consists of coloring pigments. The conventional method of coloring the asphalt mix is produced by adding color rubble or pigmenting additives. The task, which was put forward, was the establishment of such road concrete mix, from which, without the use of primary materials and without increasing the consumption of bitumen, asphalt concrete road surfaces of acceptable strength could be obtained. As a pigment the dust of gas purification system of electrical furnace DSP - 60 of «Kamastal» plant, Perm, was used. The composition of the dust waste from the furnace consists of metal oxides and silicates. Dust-gas-cleaning is a fine powder with a high specific surface (1.2…2.5 thousand cm /g and bulk density of 3.7…4.2 g/cm . The powder color is dark brown. The density of the ready colored asphalt samples is 2.47...2.49 g/cm , and water saturation is 3.50…3.55 %. As a result of the research the diagrams of the dependence of road concrete mix’s water saturation from dust percentage and a diagram of dependence of concrete mixes’ durability from dust percentage at t = 20° and 50° C were built. After analyzing the obtained curves it can be concluded that the increase of the percentage of dust leads to increase of water saturation of road concrete mix and reduced strength. Thus, the developed asphalt concrete mix allows visually separating the lanes on the road, it has the relevant regulatory requirements durability and water resistance. This mixture corresponds to the type B mark III and can be used in regions I, II, and partly III of road-climatic zones

  17. Waterproofing Underground Concrete Structures

    Science.gov (United States)

    1990-01-01

    of 100 mils for chloroprene modified asphalt and 85 mils for bitumen modified urethane waterproofing membranes. (3) Adhesion and elongation...properties are excellent. Elongation is 800% with 𔃻TdFF-N-DRI" versus 700% using bitumen modified urethane products. ŕUFF-N-DRI" is hot applied and adhesion ...Foundation ................................ 8 2 - Vertical Membrane Waterproofing System .............. 10 3 - Aggregate Drainage System and MIRADRAIN

  18. Sulfur extended asphalt pavement evaluation in the State of Washington: SR 270 highway pavement performance report

    Science.gov (United States)

    Mahoney, J. P.; Terrel, R. L.; Cook, J. C.

    1982-11-01

    The placement and performance of sulfur extended asphalt (SEA) paving mixtures at a highway test site (SR 270) near Pullman, Washington is summarized. The mixture and structural designs and construction details are included. This is followed by a discussion of the data collection and analysis accomplished over a three year evaluation period (1979-1982). A major experimental feature of the study was the use of 0.100 (conventional asphalt concrete), 30/70 and 40/60 SEA binder ratios (sulfur/asphalt ratios are expressed as weight percents in the experimental paving mixtures.

  19. HIGHLY EFFECTIVE CHEMICAL MODIFIERS FOR PRODUCTION OF CONCRETES WITH PRE-SET PROPERTIES

    OpenAIRE

    2012-01-01

    The paper demonstrates the application of industrial by-products and recycled materials. Waterproofing admixtures improve the structure and the properties of the cement stone. Development and preparation of highly effective waterproofing modifiers of durable effect, as well as development of the process procedure parameters, including mixing, activation, heat treatment, etc. are to be implemented. The composition of waterproofing modifiers is to be fine-tuned to synergize the behaviour of var...

  20. 多聚磷酸与橡胶粉复合改性沥青及其混合料在西藏地区的应用研究%Study on Application of Polyphosphate and Rubber Composite Modified Asphalt and Its Mixture in the Tibet Region

    Institute of Scientific and Technical Information of China (English)

    李郑

    2016-01-01

    Tibet intense ultraviolet radiation,large DIF and other climatic conditions put higher re-quirement on aging resistance and low crack resistance of asphalt mixture.To improve the durability of as-phalt mixture in Tibet,this article is subject to Tibet highway Lalin and proposed using polyphosphate and rubber powder composite modified asphalt,using rutting test study on the effects of the rubber powder and poly phosphoric acid(PPA)content on of the high temperature stability of composite modified asphalt mix-ture,and based on laboratory simulation aging tests,to study the affect of cracking resistance of composite modified asphalt mixture before and after heat aging and UV aging with different PPA and rubber powder content,Accelerated loading test out the preferred composite modified asphalt complex programs were screened,and with SBS modified bitumen were compared.recommend the best solution for 20 percent compound rubber powder +1.25% PPA.%西藏地区紫外线辐射强烈、昼夜温差大等气候条件对沥青混合料的抗老化性能和低抗裂性提出了更高要求。为改善西藏地区沥青混合料的耐久性,以西藏拉林高速公路为背景提出采用多聚磷酸与橡胶粉进行复配,在优选出4种复配方案的基础上,采用车辙试验研究了橡胶粉和多聚磷酸(PPA)掺量对复合改性沥青混合料高温稳定性的影响,并基于室内模拟老化试验,采用低温弯曲试验研究了紫外线老化与热老化前后 PPA 与橡胶粉掺量沥青混合料低温抗裂性能的影响,采用加速加载试验对优选出来的复合改性沥青复配方案进行了筛选,并将其与 SBS 改性沥青进行了对比。推荐最佳的复配方案为20%橡胶粉+1.25%PPA。

  1. An atomistic-based chemophysical environment for evaluating asphalt oxidation and antioxidants.

    Science.gov (United States)

    Pan, Tongyan; Sun, Lu; Yu, Qifeng

    2012-12-01

    Asphalt binders in service conditions are subject to oxidative aging that involves the reactions between oxygen molecules and the component species of bulk asphalt. As a result, significant alterations can occur to the desired physical and/or mechanical properties of asphalt. A common practice to alleviate asphalt aging has been to employ different chemical additives or modifiers as antioxidants. The current state of knowledge in asphalt oxidation and antioxidant evaluation is centered on determining the degradation of asphalt physical properties, mainly the viscosity and ductility. Such practices, although meeting direct engineering needs, do not contribute to the fundamental understanding of the aging and anti-oxidation mechanisms, and thereby developing anti-aging strategies. From this standpoint, this study was initiated to study the chemical and physical bases of asphalt oxidation, as well as the anti-oxidation mechanisms of bio-based antioxidants using the coniferyl-alcohol lignin as an example. A quantum chemistry (QC) based chemophysical environment is developed, in which the various chemical reactions between asphalt component species and oxygen, as well as the incurred physical changes are studied. X-ray photoelectron spectroscopy (XPS) was used to validate the modified and unmodified asphalt models.

  2. RESISTENCIA MECÁNICA EVALUADA EN EL ENSAYO MARSHALL DE MEZCLAS DENSAS EN CALIENTE ELABORADAS CON ASFALTOS MODIFICADOS CON DESECHOS DE POLICLORURO DE VINILO (PVC, POLIETILENO DE ALTA DENSIDAD (PEAD Y POLIESTIRENO (PS MECHANICAL RESISTANCE OF HOT THICK MIXTURES MADE WITH ASPHALT MODIFIED WITH POLYVINYL CHLORIDE, POLYCLORURE (PVC WASTES, HIGH DENSITY POLYETHYLENE (PEAD, AND POLYSTYRENE (PS EVALUATED IN MARSHALL ASSAY

    Directory of Open Access Journals (Sweden)

    Hugo Alexánder Rondón Quintana

    2007-07-01

    Full Text Available El presente trabajo buscó evaluar en laboratorio el cambio en la resistencia mecánica que experimentan mezclas asfálticas densas en caliente cuando se adicionan, por vía húmeda, al cemento asfáltico aditivos poliméricos producto de desechos industriales del tipo plastómero (policloruro de vinilo, polietileno de alta densidad y poliestireno. Para tal fin se empleó el ensayo Marshall. De los resultados obtenidos se concluye que la resistencia mecánica de mezclas asfálticas modificadas con desechos del tipo plastómero es mayor en comparación con las convencionales (mezclas que emplean asfaltos sin ningún aditivo.The main objective of this research Project was to evaluate in a laboratory the change in mechanical strength that dense hot asphalt mixtures go through when waste polymeric additives of plastomeric type (polyvinyl chloride, high density polyethylene and polystyrene are added to asphalt cement, by 'wet way'. This change was evaluated using Marshall Test. The general conclusion of the experimental results was that modified hot asphalt mixtures present better mechanical behavior than conventional mixtures (mixtures which use asphalt without additives.

  3. Asphalt mixtures with a high amount of RAP – case study

    Science.gov (United States)

    Koudelka, Tomas; Varaus, Michal

    2017-09-01

    A case study of one trial section in the Pilsen region is presented. The pavement in the section was newly constructed in 2015 using one type of an asphalt concrete mixtures with varying RAP content. The constructed surface course comprises of 0% to 50% RAP. In order to restore the aged binder properties and to avoid the embrittlement of the produced mixtures, a rubber-based modifier/rejuvenator was employed. For technological reasons during manufacturing processes, which engage a parallel drying drum, a crude oil-based rejuvenator was also added. This article contains the preliminary data from an on-going project focused on monitoring the properties of bituminous binders contained in asphalt mixtures. The actual bituminous binders were extracted straight after production, after 6 months and after 12 months. The binder characteristics are evaluated using empirical testing as well as functional tests. Low temperature properties are measured by a Bending Beam Rheometer (BBR). The preliminary results show, that the bituminous binders properties change significantly in a relatively short period of time. The progress in binder’ characteristics is contradictory to up-to date knowledge. The probability that the phenomenon of diffusion between aged binder and rejuvenator agents occurs exists. Moreover, the data might indicate that the process of rejuvenator evaporation takes place.

  4. Asphalt for draining pavement; Haisuisei hosoyo asphalt

    Energy Technology Data Exchange (ETDEWEB)

    Yamamori, H.; Nakamura, Y. [Mitsubishi Oil Co. Ltd., Tokyo (Japan)

    1994-12-28

    The effect and functions of draining pavement with a superb performance as a paved road were introduced. In the draining pavement, a porous asphalt mixture was used for the surface and base layers of the road and the remaining layers are not in water penetration property. It is necessary that void continues to prevent water film from being generated when rain falls and resistance against water flow is small but durability has problems when the void rate is large. According to the balance, the void rate ranges from 20 to 23 % for execution, thus preventing water splash on a rainy day, hydroplaning, and dazzlement, etc. due to reflection of light. The noise during driving due to the tire of an automobile is reduced by 5 to 6 dB owing to draining pavement. Also, engine noise is reduced to 40 - 60 % since the surface is porous. In the draining pavement, a high-viscosity asphalt is used for a binder and the void rate is large, thus preventing temperature to rise easily due to heat release and achieving an improved flow behavior. 6 refs., 11 figs., 14 tabs.

  5. Laboratory evaluation of selected tar sand asphalts

    Energy Technology Data Exchange (ETDEWEB)

    Button, J.W.; Epps, J.A.; Gallaway, B.M.

    1980-12-01

    Three tar sand asphalts of similar grades prepared from one syncrude by three different refining methods were characterized by tests commonly used to specify paving asphalts together with certain special tests. Asphalt-aggregate mixtures were prepared using these asphalts and tested in the laboratory to determine strength stiffness stability, tensile properties, temperature effects and water susceptibility. Comparison of the tar sand asphalt properties to conventional petroleum asphalt properties reveal no striking differences.

  6. Analysis of asphalt mixtures on town roads

    OpenAIRE

    Glavica, Primož

    2006-01-01

    Asphalt mixtures are most commonly used composite for construction of top layers of different drive ways. By definition asphalt mixtures are composed of crushed rock, fill, bitumen and additives. Percentage of individual components wary according to the purpose asphalt mixture is to be used for. Asphalt mixtures must be capable of enduring different types of load. According to the type of load asphalt mixtures are divided into asphalt mixtures used for supporting layers and asp...

  7. Drying and Heating Modelling of Granular Flow: Application to the Mix-Asphalt Processes

    Directory of Open Access Journals (Sweden)

    L Le Guen

    2011-01-01

    Full Text Available Concrete asphalt is a hydrocarbon material that includes a mix of mineral components along with a bituminous binder. Prior to mixing, its production protocol requires drying and heating the aggregates. Generally performed in a rotary drum, these drying and heating steps within mix asphalt processes have never been studied from a physical perspective. We are thus proposing in the present paper to analyze the drying and heating mechanisms when granular materials and hot gases are involved in a co-current flow. This process step accounts for a large proportion of the overall energy consumed during hot-mix asphalt manufacturing. In the present context, the high energy cost associated with this step has encouraged developing new strategies specifically for the drying process. Applying new asphalt techniques so that an amount of moisture can be preserved in the asphalt concrete appears fundamental to such new strategies. This low-energy asphalt, also referred to as the "warm technique", depends heavily on a relevant prediction of the actual moisture content inside asphalt concrete during the mixing step. The purpose of this paper is to present a physical model dedicated to the evolution in temperature and moisture of granular solids throughout the drying and heating steps carried out inside a rotary drum. An initial experimental campaign to visualize inside a drum at the pilot scale (i.e. 1/3 scale has been carried out in order to describe the granular flow and establish the necessary physical assumptions for the drying and heating model. Energy and mass balance equations are solved by implementing an adequate heat and mass transfer coupling, yielding a 1D model from several parameters that in turn drives the physical modeling steps. Moreover, model results will be analyzed and compared to several measurements performed in an actual asphalt mix plant at the industrial scale (i.e. full scale.

  8. Performance of Hot Asphalt Mixtures Containing Plastic Bottles as Additive

    Directory of Open Access Journals (Sweden)

    Jan Hakeem

    2017-01-01

    Full Text Available This study focuses on evaluating the resistance of polymer modified asphalt mixes and the role played by asphalt in the realm of construction is undeniably important. Addition of polymers(PB as additives to asphalt helps to improve the strength and water repellent property of the mix and as well as helps environment in various ways and at the same time, analyzing its lower maintenance activities and service life is most important. The use of inexpensive polymers, in this case, waste polymers has without any doubt proven to be the most convenient way of reducing the cost of construction and at the same time maintaining quality. The main resolve for this research was to establish the effects of the use of plastic bottles on hot asphalt and its mixtures. In order to put this into perspective, varying percentages of asphalt mixtures were calculated and subjected to laboratory tests. The two-factor variance analysis (ANOVA was conducted to determine the significance at various confidence limits. The results indicate that the inclusion of Polyethylene Terephthalate (PET had a particularly substantial effect on the properties of asphalt. Consequently, it can encourage the re-utilization of waste in the manufacturing industry in an ecologically friendly and cost-effective way.

  9. A review of asphalt and asphalt mixture aging

    Directory of Open Access Journals (Sweden)

    Wilmar Darío Fernández-Gómez

    2012-09-01

    Full Text Available This paper presents an extensive review of the pertinent literature regarding asphalt and asphalt mixture Aging. Aging affects flexible pavement performance and is produced by intrinsic and extrinsic variables as well as exposure time. Intrinsic variables include asphalt and aggregate properties, a mixture’s asphalt content, binder film thickness and air void content; extrinsic variables are associated with production (short-term aging and exposure to environmental field conditions (long-term aging. Taken together, both variables demonstrate that aging results from three distinct mechanisms: volatilisation, oxidation and steric hardening. Temperature, pressure and photo degradation treatments are used to simulate aging in the laboratory and empirical and semi-empirical models are created to represent and study aging. Aging increases asphalt complex modulus and decreases the phase angle. Mixtures become stiffer while fatigue life becomes reduced. Carbonyl and sulfoxide group formation in asphalt are often studied as such chemical changes show oxidation in aged asphalts. The prevailing models used to predict asphalt aging are discussed, though more comprehensive research into asphalt aging is still needed.

  10. 橡胶硫化改性路用沥青紫外老化过程的研究%A Study on the UV Aging Process of Rubber Vulcanization Modified Road Asphalt

    Institute of Scientific and Technical Information of China (English)

    祁欣; 武光明; 尹亮

    2011-01-01

    In this paper, researchers study the change rules of the structure and properties of rubber vulcanization asphalt in the UV aging process. The changes of the properties of rubber vulcanization asphalt are analyzed under the condition of UV aging, with the extension and softening point as the assessing index. It is found that the changes of the extension and the softening point of rubber vulcanization asphalt is slower than the base asphalt and the changes of the sulfoxide absorption of rubber vulcanization asphalt is less than the base asphalt. The results show that the rubber vulcanization asphalt has the performance of anti-aging properties of UV.%研究了橡胶硫化沥青在紫外光老化过程中结构与性能的变化规律.以物理延展度、软化点为评价指标分析了橡胶硫化沥青在紫外线老化条件下性能的变化,发现其延展度、软化点速率慢于基质沥青,亚砜基吸收峰的变化小于基质沥青.研究结果表明,橡胶硫化沥青具有较强的抗紫外线老化的性能.

  11. Optimization of technical measures for improving high-temperature performance of asphalt-rubber mixture

    Institute of Scientific and Technical Information of China (English)

    Chuan Xiao; Tianqing Ling; Yanjun Qiu

    2013-01-01

    Asphalt-rubber pavements often become dam-aged in high-temperature regions and appear rutted or wavy, and experience slippage. To improve the high-tem-perature performance of the asphalt-rubber mixture, tech-nical measurements, such as, the optimal adjustment of gradation, technique of composite modification, and con-trol of compaction were investigated. An optimal adjust-ment of aggregate gradation based on stone matrix asphalt improves the high-temperature stability of the asphalt-rubber mixture significantly. Through composite modifi-cation, the effect of asphalt-rubber modification was enhanced, and the dynamic stability and relative defor-mation indices of the asphalt-rubber mixture were improved significantly. Furthermore, compaction parame-ters had a significant influence on the high-temperature stability of the asphalt-rubber mixture. The rolling times for compacting the asphalt-rubber mixture should be controlled to within 18-20 round-trips at a molding tem-perature at 180 ?C;if the rolling time is a 12 round-trip, the compaction temperature of the asphalt-rubber mixture should be controlled between 180 and 190 ?C.

  12. Evaluation of abrasion of a modified drainage mixture with rubber waste crushed (GCR

    Directory of Open Access Journals (Sweden)

    Yee Wan Yung Vargas

    2017-02-01

    Conclusion: The results showed that there is a highlighted influence of mix temperature (between asphalt and GCR and compaction temperature (modified asphalt and aggregate on the behavior of the MD modified with GCR.

  13. Research on the impacts of modified asphalt on the property of OGFC mixture%改性沥青对OGFC混合料性能的影响研究

    Institute of Scientific and Technical Information of China (English)

    时威

    2011-01-01

    Based on the three types of modified asphalt mixture rutting test in high temperature,low temperature bending test,permeability test and performance test sliding,the paper analyzes mixed with agent types on mixture properties of impact.The results showed that: mixed agent types,mixture showed a greater difference in performance,proposed OGFC paved road in the future,the choice should be mixed with specific agent types.%通过对三种类型的改性沥青混合料进行高温车辙试验、低温弯曲试验、透水性试验以及抗滑性能试验,分析了外掺剂类型对混合料路用性能产生的影响。结果表明:外掺剂类型不同,混合料的路用性能表现出较大差异;建议在铺筑OGFC路面时,要有针对性的选择外掺剂类型。

  14. Dynamic Response Analysis of Asphalt Concrete Pavement with Permeable Base Considering Moving and Overload Effect of Vehicles%考虑车辆移动效应和超载的排水基层路面结构动力分析

    Institute of Scientific and Technical Information of China (English)

    欧金秋; 崔新壮; 王聪; 郑骁

    2011-01-01

    In order to study the dynamic response of asphalt concrete pavement with permeable base under vehicle loads, based fast Lagrangian finite difference method, the dynamic analysis of asphalt concrete pavement under various conditions is conducted, considering the influence of moving vehicle load and different speed. The results show that the pavement dynamic deflection did not increase though the modulus of permeable base is low. The permeable base reduced the dynamic stress at the bottom of the subbase, which can inhibit the cracking of reflection. With the increase of speed, both the dynamic deflection and stress decreased, so in high temperature season, low-speed vehicle can cause larger rutting. Little vehicle overload can induce larger dynamic deflection and stress thus causes larger pavement deformation even plastic damage and the cracking. It is implied that the governance of overload is of great significance for extending road life and reducing maintenance costs.%为了研究车辆荷载作用下排水基层路面的动力响应,同时考虑车速和轴载的影响,采用移动加载的方法,对不同工况下沥青混凝土路面进行了快速Lagrange有限差分分析.结果表明,路面弯沉并未因排水基层的低模量而增大,峰值甚至有所减小;排水基层的存在减小了底基层底部的动应力,可以抑制反射裂缝的产生;弯沉及动应力均随车速的增大而减小,高温季节,低速行驶更容易引起大车辙;当车辆超载50%时,弯沉和动应力均成倍增大,导致路面产生较大变形甚至塑性破坏,且更容易引起路面开裂,表明治理超载对延长道路使用寿命、降低养护成本具有重要意义.

  15. Research on viscosity influence factors and macro characteristics of crumb rubber modified asphalt%胶粉改性沥青黏度影响因素及微观特性研究

    Institute of Scientific and Technical Information of China (English)

    丁湛; 栗培龙

    2011-01-01

    One method of reusing tires is to process them into crumb-sized particles and produce crumb rubber modified asphalt(CRMA).which is a an effective way of reducing the pollution and resource utilization. Rotary viscosities of CRMA prepared under different conditions were measured to analyze the effects of crumb rubber size,rubber dosage,treating temperature,treating time and microwave on the viscosities of CRMA. The electron microscope photography is used to observe the microstructure of crumb ruber in asphalt,and swelling behavior of crumb rubber was discussed. Test results indicate that the viscosity of CRMA increases with the concentration of crumb rubber and treating temperature increasing. And it increases first and then decreases with rubber particle size for the conatant concentration of crumb rubber. In this study, viscosity of 60-mesh CRMA is the largest.The microwave can strenghen the effect of crumb rubber swelling,which leads to viscosity of CRMA increase. But swelling degrees of crumb rubber are different under different conditions,whose effects on the viscosity of CRMA are different.%将废橡胶粉用于生产胶粉改性沥青(CRMA)是一种节能而又环保的有效途径.在不同条件下制备胶粉改性沥青,并进行黏度测试,分析了胶粉粒径、胶粉掺量、处理温度、处理时间以及微波条件对胶粉改性沥青黏度的影响,采用电子显微照相技术观测胶粉的微观状态变化,进行了胶粉溶胀特性探讨.结果表明,随着处理温度的升高及胶粉掺量的增大,胶粉改性沥青黏度不断增高;而随着胶粉粒径减小,胶粉改性沥青黏度先增后减,其中以60目胶粉改性沥青黏度最大;微波作用可以增强胶粉在沥青介质中的溶胀效果,使胶粉改性沥青黏度增大.在不同条件下胶粉的溶胀程度不同,对胶粉改性沥青黏度的影响也不同.

  16. EVALUATION OF TIRE RUBBER DISPOSAL IN CONCRETE FOR PAVEMENTS

    Directory of Open Access Journals (Sweden)

    Rosa Cristina Cecche Lintz

    2009-12-01

    Full Text Available The production of waste by the tire industry has been a growing problem, indicating the need for its reuse. More than thirty million tires are discharged per year in Brazil, where regulation for the environment states that for each four new tires, five unusable ones must be adequately disposed by manufacturers and importers. Paving consumes an extremely large quantity of materials, which can be the source of rational application of waste and rejected materials. Research shows that tire rubber can be added to asphalt, which increases its durability and improves pavement quality and safety conditions by absorbing the rubber elastic properties, and also be used for architectural applications, among others. This study deals with the addition of rubber fibers from tire crushing in concrete for roadway pavements in order to provide proper indication about the alternative material disposal through an evaluation of the mechanical behavior of the modified concrete. Different concrete mixes were produced, within which, part of fine aggregates were substituted by tire rubber and mechanical experiment tests were performed, which show that, due to great resistance losses, the disposal of this alternative material in concrete should be considered for light traffic pavements, with the addition of rubber ranging up to 10% in mass.

  17. EVALUATION OF TIRE RUBBER DISPOSAL IN CONCRETE FOR PAVEMENTS

    Directory of Open Access Journals (Sweden)

    Rosa Cristina Cecche Lintz

    2009-01-01

    Full Text Available The production of waste by the tire industry has been a growing problem, indicating the need for its reuse. More than thirty million tires are discharged per year in Brazil, where regulation for the environment states that for each four new tires, five unusable ones must be adequately disposed by manufacturers and importers. Paving consumes an extremely large quantity of materials, which can be the source of rational application of waste and rejected materials. Research shows that tire rubber can be added to asphalt, which increases its durability and improves pavement quality and safety conditions by absorbing the rubber elastic properties, and also be used for architectural applications, among others. This study deals with the addition of rubber fibers from tire crushing in concrete for roadway pavements in order to provide proper indication about the alternative material disposal through an evaluation of the mechanical behavior of the modified concrete. Different concrete mixes were produced, within which, part of fine aggregates were substituted by tire rubber and mechanical experiment tests were performed, which show that, due to great resistance losses, the disposal of this alternative material in concrete should be considered for light traffic pavements, with the addition of rubber ranging up to 10% in mass.

  18. 改性石墨对蓄热混凝土的性能影响研究%Prperties Research of Modified Graphite to Heat Storage Concrete

    Institute of Scientific and Technical Information of China (English)

    朱建在; 荆汝林; 邱河梅; 成斌; 朱教群; 周卫兵; 孙正

    2014-01-01

    On the basis of the previous studies,the graphite powder mixed into concrete was investigated in this pa-per.Effect of modified graphite powder on the performance of heat storage concrete were researched.This result indica-ted that the modified graphite powder can reduce the moisture absorption of concrete and increase the working perform-ance of regenerative concrete.Coated in a layer of SiO2 film,the modified graphite powder reduced the strength of con-crete and the coefficient of thermal conductivity.However,the coefficient of thermal conductivity was still up to 2.54 W/(m·K),which had a good application value.%在前期研究的蓄热混凝土基础上,通过石墨粉改性前后混凝土的性能比较,研究改性石墨粉对蓄热混凝土性能的影响。研究表明,改性石墨粉可以降低混凝土的吸湿性,增加蓄热混凝土的工作性能和强度。由于改性石墨粉表面包覆一层 SiO2薄膜,降低了该混凝土的导热系数,但是降低幅度为8%,其导热系数为2.54 W/(m·K),仍然具有较好的导热性。

  19. Modeling Recycling Asphalt Pavement Processing Technologies in Asphalt Mixing Plants

    OpenAIRE

    Simonas Tamaliūnas; Henrikas Sivilevičius

    2011-01-01

    The article presents reclaimed asphalt pavement (RAP) processing technologies and equipment models used in the asphalt mixing plant (AMP). The schematic model indicating all possible ways to process RAP in AMP is shown. The model calculating the needed temperature of mineral materials used for heating RAP is given and an example of such calculation is provided.Article in Lithuanian

  20. Modeling Recycling Asphalt Pavement Processing Technologies in Asphalt Mixing Plants

    Directory of Open Access Journals (Sweden)

    Simonas Tamaliūnas

    2011-04-01

    Full Text Available The article presents reclaimed asphalt pavement (RAP processing technologies and equipment models used in the asphalt mixing plant (AMP. The schematic model indicating all possible ways to process RAP in AMP is shown. The model calculating the needed temperature of mineral materials used for heating RAP is given and an example of such calculation is provided.Article in Lithuanian

  1. Prevention of reinforcement corrosion by hydrophobic treatment of concrete

    NARCIS (Netherlands)

    Polder, R.B.; Borsje, H.; Vries, H. de

    2001-01-01

    Corrosion of reinforcement in concrete bridge decks may occur due to penetration of de-icing salts, even in the presence of an asphalt overlay. This paper reports a laboratory study into additional protection of concrete by hydrophobic treatment. It was found that hydrophobic treatment strongly redu

  2. Dead sea asphalts: historical aspects

    Energy Technology Data Exchange (ETDEWEB)

    Nissenbaum, A.

    1978-05-01

    Asphalts are present in the Dead Sea basin in three forms: (1) huge blocks, up to 100 tons in weight, composed of extremely pure (>99.99%) solid asphalt occasionally found floating on the lake, (2) veins, seepages, and cavity and fissure fillings in Lower Cretaceous to Holocene rocks, and (3) ozocerite veins on the eastern shore of the lake. Dead Sea asphalts probably have been documented over a longer period of time than any other hydrocarbon deposit--from antiquity to the 19th century. Major uses of asphalt from the Dead Sea have been as an ingredient in the embalming process, for medicinal purposes, for fumigation, and for agriculture. The first known war for control of a hydrocarbon deposit was in the Dead Sea area in 312 B.C. between the Seleucid Syrians and the Nabatean Arabs who lived around the lake. Surface manifestations of asphalt are linked closely to tectonic activity. In the lake itself, the asphalt is associated with diapirs During certain historic periods, tectonic and diapiric activity caused frequent liberation to the Dead Sea surface of semiliquid asphalt associated with large amounts of hydrogen sulfide gas. When the tectonic activity was attenuated, as in the 19th and 20th centuries, the rate of asphalt seepage to the bottom sediments of the Dead Sea was much slower and the asphalt solidified on the lake bottom. The release of asphalt to the surface became much more sporadic, and may have resulted in part from earthquakes. Thus, future asphalt prospecting in the Dead Sea area should be conducted along the boundaries of diapirs or their associated faults.

  3. The Utilization of Graphene Oxide in Traditional Construction Materials: Asphalt

    Directory of Open Access Journals (Sweden)

    Wenbo Zeng

    2017-01-01

    Full Text Available In the advanced research fields of solar cell and energy storing materials, graphene and graphene oxide (GO are two of the most promising materials due to their high specific surface area, and excellent electrical and physical properties. However, they was seldom studied in the traditional materials because of their high cost. Nowadays, graphene and GO are much cheaper than before with the development of production technologies, which provides the possibility of using these extraordinary materials in the traditional construction industry. In this paper, GO was selected as a nano-material to modify two different asphalts. Then a thin film oven test and a pressure aging vessel test were applied to simulate the aging of GO-modified asphalts. After thermal aging, basic physical properties (softening point and penetration were tested for the samples which were introduced at different mass ratios of GO (1% and 3% to asphalt. In addition, rheological properties were tested to investigate how GO could influence the asphalts by dynamic shearing rheometer tests. Finally, some interesting findings and potential utilization (warm mixing and flame retardants of GO in asphalt pavement construction were explained.

  4. PVC塑料改性混凝土的温度挥发性研究实验分析%PVC Plastic Modified Concrete Temperature Volatile Research Analysis

    Institute of Scientific and Technical Information of China (English)

    罗海艳

    2016-01-01

    PVC plastic particles as fine aggregate in concrete replacement material, by adjusting the dosage proportion of different PVC plastic particles, making different PVC plastic modified concrete samples. To modified the volatilization rate of concrete and compressive strength as index, the mixed quantity of PVC plastic particles is studied through experiments and heating temperature on the properties of modified concrete resistance to high temperature. Results show that the modified PVC plastic particles and high temperature resistant performance of concrete and the heating temperature, the heating temperature and the increase of the dosage of PVC plastic particles, PVC plastic modified concrete volatilize quantity increase gradually, gradually reduce the compressive strength. In the case of the same dosage of PVC plastic particles, volatilize quantity and there is a linear relationship between heating temperature.%以PVC塑料颗粒作为混凝土中细骨料的替代材料,通过调整不同PVC塑料颗粒的掺量比例,制作不同的PVC塑料改性混凝土样品。以改性混凝土的挥发率和抗压强度作为指标,通过实验研究了PVC塑料颗粒掺量和加热温度对改性混凝土耐高温性能的影响。结果表明,改性混凝土的耐高温性能与PVC塑料颗粒和加热温度有关,随着加热温度和PVC塑料颗粒掺量的增加,PVC塑料改性混凝土的挥发量逐渐增加,抗压强度逐渐降低。在相同PVC塑料颗粒掺量的情况下,挥发量与加热温度之间存在一定的线性关系。

  5. The addition effects of macro and nano clay on the performance of asphalt binder

    Directory of Open Access Journals (Sweden)

    M. El-Shafie

    2012-12-01

    Full Text Available The study was carried out to explore the addition effect of macro and organically modified nanoclay on the physical and mechanical properties of asphalt binders. Both macroclay and modified nanoclay were blended in an asphalt binder in various percentages (starting from 2% to 8%. The blended asphalt binders were characterized using kinematic viscosity (C.st, softening point (°C, and penetration and compared with anunmodified binder. The tensile strength of the asphalt binders was also tested as a function of clay types and content%. The results of the study indicated an increase in softening point; kinematics viscosity and decrease in binder penetration. The tensile strength of modified clay binders was enhanced at all percentages by a comparison with both macroclay and unmodified binders. The best improvements in the modified binders were obtained with 6% nanoclay.

  6. Asphalt rutting and its prevention

    CSIR Research Space (South Africa)

    Verhaeghe, Benoit MJA

    2007-09-01

    Full Text Available The paper seeks to redress the concerns expressed at the eight Conference on Asphalt pavements for Southern Africa (CAPSA) that the design of hot-mix asphalt did not adequately address prevention of rutting. It presents a consolidation of best...

  7. Polyurethane synthesis reactions in asphalts

    Energy Technology Data Exchange (ETDEWEB)

    Bukowski, A.; Gretkiewicz, J.

    1982-04-01

    A series of asphalt-polyurethane composites was prepared by means of polyurethane synthesis in asphalt and carried out in melt. The applied materials were asphalts of differentiated group components content, polyester polyols of chain structure from linear to strongly branched, 2,4-tolylene diisocyanate, 4,4-methylenebis(phenyl isocyanate), and tinorganic catalyst. The asphalt components react with isocyanates to a minimal degree. The influence of the applied substrates, temperature, and polyurethane content in the system on the basic kinetic relations characterizing the process is presented. Polyurethane synthesis in asphalts does not differ in a fundamental way from the obtaining of polyurethanes, especially when their content in the composition is significant, 20 wt% and more.

  8. How Concrete Is Concrete?

    Science.gov (United States)

    Gravemeijer, Koeno

    2011-01-01

    If we want to make something concrete in mathematics education, we are inclined introduce, what we call, "manipulatives", in the form of tactile objects or visual representations. If we want to make something concrete in a everyday-life conversation, we look for an example. In the former, we try to make a concrete model of our own,…

  9. Caltrans use of scrap tires in asphalt rubber products: a comprehensive review

    Directory of Open Access Journals (Sweden)

    Haiping Zhou

    2014-02-01

    Full Text Available The California Department of Transportation (Caltrans has been using scrap tire rubber in asphalt pavements since the 1970s in chip seals and the 1980s in rubberized hot mix asphalt(RHMA. Both the wet (field blend and dry processes were used in early trials. Caltrans has also used rubber modified binders containing both crumb rubber modifier and polymer modifier that could be manufactured at a refinery facility, a terminal blend wet process. Since the beginning of this century, Caltrans increased the use of scrap tire rubber in paving projects and invested considerable resources in developing technically sound, cost effective, and environmentally friendly strategies for using scrap tire rubber in roadway applications. By the end of year 2010, approximately 31%of all hot mix asphalt (HMA placed by Caltrans was rubberized HMA, roughly 1.2 million tons. Caltrans efforts in using asphalt rubber products were also demonstrated in its research and technology development. These included the construction of two full-scale field experiments, five warranty projects, and an accelerated pavement study using a heavy vehicle simulator. Additionally, terminal blend asphalt rubber and rubberized warm mix asphalts began to be experimented on trial basis. This paper provides a comprehensive review of Caltrans experience over four decades with asphalt rubber products. Current practices and future outlook are also discussed.

  10. Aging of Asphalt Symposium, September 17th 2014, Delft, the Netherlands

    NARCIS (Netherlands)

    Erkens, S.M.J.G.; Scarpas, A.; Blab, R.; Glaser, R.; Glover, C.; Oeser, M.; Porot, L.; Soenen, H.

    2015-01-01

    Technical specifications for the asphalt concrete properties are developed to be able to specify mixtures that will perform well in pavement applications. Being able to identify and determine properties related to pavement performance in practice is crucial for both road authorities and contractors,

  11. Experimental Investigation of the Matching Relationship between Asphalt Particle and Reservoir Pore in Profile Control Process

    Directory of Open Access Journals (Sweden)

    Chengfeng Ren

    2016-01-01

    Full Text Available Modified sulfonated asphalt particles have a bright application prospect of the profile control of thick reservoirs due to the low cost, extensive sources, and good compatibility with reservoir. Nevertheless, the matching relationship between asphalt particles and reservoir pore has seldom been investigated till now. Oversized particles always block the near-wellbore area, which causes high injection pressures, while undersized particles cannot plug large pores. We designed a core for this experiment which has a high permeability zone in front of it and many pressure measuring points. We could quantitatively assess the matching relationship by measuring the on-way resistance coefficient, residual resistance factor, and relative change of permeability of man-made cores after injecting asphalt. Experimental results indicate that asphalt particles with sizes of 0.02 mm, 0.02–0.06 mm, and 0.08–0.1 mm match with reservoir permeability of 500 mD, 1000 mD, and 2000 mD, respectively. Undersized or oversized particles can reduce the conformance control effect, and the concentration of asphalt particles in the injectant can limit their migration ability. When the concentration of asphalt particles increases to 3000 mg/L, accumulations of asphalt particles can be caused in the formation, in which a scheme with asphalt particles alternative water injection is proposed to avoid the accumulation.

  12. Application of the endochronic theory of viscoplasticity to solid propellants and sandasphalt concrete

    Science.gov (United States)

    Peng, S. T. J.; Valanis, K. C.

    1977-01-01

    Solid propellants, sand-asphalt concrete and hard plastics showed rate sensitive mechanical behavior which, in addition, indicated that these materials have a permanent memory of the strain (or loading) path by which their present state was attained. A constitutive equation was formulated in general three dimensional tensorial form by means of irreversible thermodynamics. By using a very simple analytical form, it was shown that the mechanical behavior of solid propellants and sand-asphalt concrete can be readily described.

  13. Interaction nonlinearity in asphalt binders

    Science.gov (United States)

    Motamed, Arash; Bhasin, Amit; Liechti, Kenneth M.

    2012-05-01

    Asphalt mixtures are complex composites that comprise aggregate, asphalt binder, and air. Several research studies have shown that the mechanical behavior of the asphalt mixture is strongly influenced by the matrix, i.e. the asphalt binder. Characterization and a thorough understanding of the binder behavior is the first and crucial step towards developing an accurate constitutive model for the composite. Accurate constitutive models for the constituent materials are critical to ensure accurate performance predictions at a material and structural level using micromechanics. This paper presents the findings from a systematic investigation into the nature of the linear and nonlinear response of asphalt binders subjected to different types of loading using the Dynamic Shear Rheometer (DSR). Laboratory test data show that a compressive normal force is generated in an axially constrained specimen subjected to torsional shear. This paper investigates the source of this normal force and demonstrates that the asphalt binder can dilate when subjected to shear loads. This paper also presents the findings from a study conducted to investigate the source of the nonlinearity in the asphalt binder. Test results demonstrate that the application of cyclic shear loads results in the development of a normal force and a concomitant reduction in the dynamic shear modulus. This form of nonlinear response is referred to as an "interaction nonlinearity". A combination of experimental and analytical tools is used to demonstrate and verify the presence of this interaction nonlinearity in asphalt binders. The findings from this study highlight the importance of modeling the mechanical behavior of asphalt binders based on the overall stress state of the material.

  14. Corrosion-resistant sulfur concretes

    Science.gov (United States)

    McBee, W. C.; Sullivan, T. A.; Jong, B. W.

    1983-04-01

    Sulfur concretes have been developed by the Bureau of Mines as construction materials with physical and mechanical properties that suit them for use in acid and salt corrosive environments where conventional concretes fail. Mixture design methods were established for preparing sulfur concretes using different types of aggregates and recently developed mixed-modified sulfur cements. Bench-scale testing of the sulfur concretes has shown their potential value. Corrosion resistance, strength, and durability of sulfur concrete are superior to those of conventional materials. Field in situ evaluation tests of the sulfur concretes as replacement for conventional concrete materials are in progress in corrosive areas of 24 commercial chemical, fertilizer, and metallurgical plants.

  15. 75 FR 12988 - National Emission Standards for Hazardous Air Pollutants for Area Sources: Asphalt Processing and...

    Science.gov (United States)

    2010-03-18

    ... Sources: Asphalt Processing and Asphalt Roofing Manufacturing; Technical Correction AGENCY: Environmental... the asphalt processing and asphalt roofing manufacturing area source category (74 FR 63236). Following... the asphalt processing and asphalt roofing manufacturing area source category on December 2, 2009...

  16. 基于灰关联理论的橡胶粉改性沥青热老化性能研究%Research on Thermal Ageing Performance of Rubber Powder Modified Asphalt Based on Grey Associative Theory

    Institute of Scientific and Technical Information of China (English)

    王宝松; 叶奋

    2012-01-01

    This paper analyzes influences of preparation technology of rubber asphalt on ageing performance of rubber asphalt based on grey associative theory. In order to guarantee accuracy of research on ageing performance of rubber asphalt, .the paper adopts the isolated variable method to test by fixing other factors and transforming single factor and analyze influences of various factors on performance of rubber asphalt. The paper employs grey associative analysis method to analyze degrees of association of multiple groups of data, to study degrees of, association of all influence factors with ageing performance of rubber asphalt, and to determine key factors that affect ageing performance of rubber asphalt.%基于灰关联理论,分析橡胶沥青制备工艺对橡胶沥青老化性能的影响.为保证橡胶沥青老化性能研究的准确性,采用“孤立变量法”,通过固定其他因素并变换单个因素进行试验,分析各种因素对橡胶沥青性能的影响.采用灰关联分析方法对多组数据进行关联度分析,研究各影响因素与橡胶沥青老化性能的关联度大小,确定影响橡胶沥青老化性能的关键因素.

  17. Modification of local asphalt with epoxy resin to be used in pavement

    Directory of Open Access Journals (Sweden)

    A.M.M. Abd El Rahman

    2012-12-01

    Full Text Available The durability of asphalt pavement is greatly influenced by the environmental changes during the year. In this paper, we prepared asphalt modified by mixing asphalt 60/70 with epoxidized natural rubber (ENR in different percentages (5, 10 and 15%, which was achieved using preformed peracetic acid (aqueous solution 59% at 60–80 °C, then molten cross-linker maleic anhydride (MA was added to modified asphalt until homogenous blends are achieved. Marshall test was used to evaluate the asphalt pavement performance depending on the curing time and hardener concentration. To measure marshall test, the pervious mixture was stirred with aggregate jop formula mix (JMF and 40% MA at 150–170 °C for 20 h and 1600 rpm. From the obtained data, it was found that asphalt mixed with 15% of ENR + 40% MA achieves a high stability (16,632 Newton, air voids of 2.5%, flow of 2.9 mm and mineral voids of 14.6%. While, the stability of the unmodified asphalt was (11,500 Newton, the flow 3.2 mm, the suitable air void value was 3.7% at 5.5% with the same conditions.

  18. 胶粉稳定苯乙烯-丁二烯-苯乙烯三嵌段共聚物改性沥青的结构与性能%Structure and properties of styrene-butadiene-styrene triblock copolymer modified asphalt stabilized by ground tire rubber

    Institute of Scientific and Technical Information of China (English)

    姚鸿儒; 周帅; 王仕峰; 张勇; 张隐西

    2015-01-01

    将苯乙烯-丁二烯-苯乙烯三嵌段共聚物(SBS)、废旧轮胎胶粉(GTR)和相容剂环氧天然橡胶(ENR)熔融共混,然后再分散到沥青中制备了 SBS/ GTR 复合改性沥青,考察了 ENR 含量、SBS/ GTR (质量比)对复合改性沥青热储存稳定性和基本性能的影响。结果表明,随着 ENR 含量的增加或 SBS含量的减少,SBS/ GTR 复合改性沥青的热储存稳定性提高,当 ENR 质量分数为1.0%、SBS/ GTR 为50/50时,复合改性沥青的热储存稳定性最佳;随着 ENR 含量的增加,SBS/ GTR 复合改性沥青的软化点、针入度、延度和黏度变化不大,但当 ENR 质量分数为10.0%时,改性沥青的软化点明显升高,针入度下降,属于一种比较硬质的改性沥青,具有较好的施工和易性;随着 SBS 含量的减少,SBS/ GTR 复合改性沥青的软化点、黏度和延度均降低。%Storage-stable styrene-butadiene-styrene triblock copolymer (SBS) / ground tire rubber (GTR) hybrid modified asphalts were prepared by dispersing the melt blend of SBS, GTR and epoxidized natural rubber (ENR) into base asphalt. Effects of ENR content, SBS/ GTR(mass ratio) on storage sta-bility, phase structure and properties were studied. The results showed that the storage stability of the modified asphalt was improved with the increase of ENR content or decrease of SBS content, and the modified asphalt achieved the best storage stability when mass fraction of ENR was 1. 0% and SBS/ GTR was 50/ 50. ENR content had a slight influence on the soften-ing points, penetration, ductility and viscosity of hybrid bind-ers, however, when the mass fraction of ENR reached 10. 0% , softening points increased and penetration decreased obviously, and the modified asphalt was hard and easy to oper-ate. The softening points, viscosity and ductility of the modi-fied asphalt all decreased with the decrease of SBS content.

  19. Effect of Zn/Al Layered Double Hydroxide Containing 2-Hydroxy-4-n-octoxy-benzophenone on UV Aging Resistance of Asphalt

    Directory of Open Access Journals (Sweden)

    Chao Peng

    2015-01-01

    Full Text Available UV radiation is a main factor to reduce the service life of asphalt pavement due to the UV aging of asphalt binder. To obtain enhanced UV aging resistance, an organic UV absorber called 2-hydroxy-4-n-octoxy-benzophenone (HNOB had been intercalated into an inorganic UV absorber called Zn/Al layered double hydroxide (LDH to play a combined anti-UV role in asphalt binder. Fourier transform infrared spectroscopy revealed that HNOB anions have been intercalated into the interlayer galleries of Zn/Al-LDH containing HNOB anions (Zn/Al-HNOB−-LDH. X-ray diffraction results of Zn/Al-LDH containing CO32− anions (Zn/Al-CO32--LDH and Zn/Al-CO32--LDH/styrene-butadiene-styrene (SBS modified asphalt disclosed that asphalt molecules entered into LDH interlayer galleries to form an expanded phase structure. UV-Vis absorbance patterns showed that Zn/Al-HNOB−-LDH has a better capacity of blocking UV light due to the synergetic effect of HNOB and Zn/Al-LDH. The chemical fractions analysis, conventional physical tests, and rheological tests of SBS modified asphalt, Zn/Al-CO32--LDH/SBS modified asphalt, and Zn/Al-HNOB−-LDH/SBS modified asphalt before and after UV aging testified that Zn/Al-HNOB−-LDH can improve the UV aging resistance of SBS modified asphalt more significantly.

  20. Ultrasound data for laboratory calibration of an analytical model to calculate crack depth on asphalt pavements

    Directory of Open Access Journals (Sweden)

    Miguel A. Franesqui

    2017-08-01

    Full Text Available This article outlines the ultrasound data employed to calibrate in the laboratory an analytical model that permits the calculation of the depth of partial-depth surface-initiated cracks on bituminous pavements using this non-destructive technique. This initial calibration is required so that the model provides sufficient precision during practical application. The ultrasonic pulse transit times were measured on beam samples of different asphalt mixtures (semi-dense asphalt concrete AC-S; asphalt concrete for very thin layers BBTM; and porous asphalt PA. The cracks on the laboratory samples were simulated by means of notches of variable depths. With the data of ultrasound transmission time ratios, curve-fittings were carried out on the analytical model, thus determining the regression parameters and their statistical dispersion. The calibrated models obtained from laboratory datasets were subsequently applied to auscultate the evolution of the crack depth after microwaves exposure in the research article entitled “Top-down cracking self-healing of asphalt pavements with steel filler from industrial waste applying microwaves” (Franesqui et al., 2017 [1].

  1. Ultrasound data for laboratory calibration of an analytical model to calculate crack depth on asphalt pavements.

    Science.gov (United States)

    Franesqui, Miguel A; Yepes, Jorge; García-González, Cándida

    2017-08-01

    This article outlines the ultrasound data employed to calibrate in the laboratory an analytical model that permits the calculation of the depth of partial-depth surface-initiated cracks on bituminous pavements using this non-destructive technique. This initial calibration is required so that the model provides sufficient precision during practical application. The ultrasonic pulse transit times were measured on beam samples of different asphalt mixtures (semi-dense asphalt concrete AC-S; asphalt concrete for very thin layers BBTM; and porous asphalt PA). The cracks on the laboratory samples were simulated by means of notches of variable depths. With the data of ultrasound transmission time ratios, curve-fittings were carried out on the analytical model, thus determining the regression parameters and their statistical dispersion. The calibrated models obtained from laboratory datasets were subsequently applied to auscultate the evolution of the crack depth after microwaves exposure in the research article entitled "Top-down cracking self-healing of asphalt pavements with steel filler from industrial waste applying microwaves" (Franesqui et al., 2017) [1].

  2. Curing Behavior of Epoxy Asphalt

    Institute of Scientific and Technical Information of China (English)

    YU Jianying; CONG Peiliang; WU Shaopeng; CHENG Songbo

    2009-01-01

    The curing process of epoxy asphalt was analyzed by Fourier transform infrared (FT-IR)spectroscopy.Effect of curing temperature on viscosity of epoxy asphalt,and changes of mechanical properties with curing time were investigated.The evolution of concentration of epoxy band was followed as a function of the applied curing process.The experimental results indicate that the curing reaction rate of epoxy asphalt is invariable before 70 min at 120℃,and it decreases when curing time exceeds 70 min.The viscosity of epoxy asphalt increases slowly with curing time at initial curing stage.But it increases quickly after initial curing stage and the initial curing time decreases as the curing temperature increases.The tensile strength increases slowly at incipient curing stage and increases rapidly when curing time is form 20 min to 70 min.The elongation at break shows a decrease with curing time,but it exceeds 200%after cured.

  3. Airborne Exposures to Polycyclic Aromatic Compounds Among Workers in Asphalt Roofing Manufacturing Facilities.

    Science.gov (United States)

    Trumbore, David C; Osborn, Linda V; Johnson, Kathleen A; Fayerweather, William E

    2015-01-01

    We studied exposure of 151 workers to polycyclic aromatic compounds and asphalt emissions during the manufacturing of asphalt roofing products-including 64 workers from 10 asphalt plants producing oxidized, straight-run, cutback, and wax- or polymer-modified asphalts, and 87 workers from 11 roofing plants producing asphalt shingles and granulated roll roofing. The facilities were located throughout the United States and used asphalt from many refiners and crude oils. This article helps fill a gap in exposure data for asphalt roofing manufacturing workers by using a fluorescence technique that targets biologically active 4-6 ring polycyclic aromatic compounds and is strongly correlated with carcinogenic activity in animal studies. Worker exposures to polycyclic aromatic compounds were compared between manufacturing plants, at different temperatures and using different raw materials, and to important external benchmarks. High levels of fine limestone particulate in the plant air during roofing manufacturing increased polycyclic aromatic compound exposure, resulting in the hypothesis that the particulate brought adsorbed polycyclic aromatic compounds to the worker breathing zone. Elevated asphalt temperatures increased exposures during the pouring of asphalt. Co-exposures in these workplaces which act as confounders for both the measurement of total organic matter and fluorescence were detected and their influence discussed. Exposures to polycyclic aromatic compounds in asphalt roofing manufacturing facilities were lower than or similar to those reported in hot-mix paving application studies, and much below those reported in studies of hot application of built-up roofing asphalt. These relatively low exposures in manufacturing are primarily attributed to air emission controls in the facilities, and the relatively moderate temperatures, compared to built-up roofing, used in these facilities for oxidized asphalt. The exposure to polycyclic aromatic compounds was a very

  4. Hanford Permanent Isolation Barrier Program: Asphalt technology data and status report - FY 1994

    Energy Technology Data Exchange (ETDEWEB)

    Freeman, H.D.; Romine, R.A.; Zacher, A.H.

    1994-09-01

    The asphalt layer within the Hanford Permanent Isolation Barrier (HPIB) is an important component of the overall design. This layer provides a RCRA equivalent backup to the overlying earthen layers in the unlikely event that these layers are not able to reduce the infiltration rate to less than 0.05 cm/yr. There is only limited amount of information on using asphalt for a moisture infiltration barrier over the long times required by the HPIB. Therefore, a number of activities are under way, as part of the Barrier Development Program, to obtain data on the performance of asphalt as a moisture barrier in a buried environment over a 1000-year period. These activities include (1) determining RCRA equivalency, (2) measurement of physical properties, (3) measurement of aging characteristics, and (4) relationship to ancient asphalt analogs. During FY 1994 progress was made on all of these activities. Studies were conducted both in the laboratory and on the prototype barrier constructed over the 216-B-57 crib in the 200 East Area on the Hanford Site. This report presents results obtained from the asphalt technology tasks during FY 1994. Also included are updates to planned activities for asphalt analogs and monitoring the asphalt test pad near the prototype barrier. Measurements of hydraulic conductivity on the HMAC portion of the prototype barrier show that the asphalt layers easily meet the RCRA standard of 1 {times} 10{sup -7} cm/s. In-place measurements using a new field falling head technique show an average of 3.66 {times} 10{sup -8} cm/s, while cores taken from the north end of the prototype and measured in a laboratory setup averaged 1.29 {times} 10{sup -9} cm/s. Measurements made on the fluid applied asphalt membrane (polymer-modified asphalt) show an extremely low permeability of less than 1 {times} 10{sup -11} cm/s.

  5. A review on using crumb rubber in reinforcement of asphalt pavement.

    Science.gov (United States)

    Mashaan, Nuha Salim; Ali, Asim Hassan; Karim, Mohamed Rehan; Abdelaziz, Mahrez

    2014-01-01

    An immense problem affecting environmental pollution is the increase of waste tyre vehicles. In an attempt to decrease the magnitude of this issue, crumb rubber modifier (CRM) obtained from waste tyre rubber has gained interest in asphalt reinforcement. The use of crumb rubber in the reinforcement of asphalt is considered as a smart solution for sustainable development by reusing waste materials, and it is believed that crumb rubber modifier (CRM) could be an alternative polymer material in improving hot mix asphalt performance properties. In this paper, a critical review on the use of crumb rubber in reinforcement of asphalt pavement will be presented and discussed. It will also include a review on the effects of CRM on the stiffness, rutting, and fatigue resistance of road pavement construction.

  6. A Review on Using Crumb Rubber in Reinforcement of Asphalt Pavement

    Directory of Open Access Journals (Sweden)

    Nuha Salim Mashaan

    2014-01-01

    Full Text Available An immense problem affecting environmental pollution is the increase of waste tyre vehicles. In an attempt to decrease the magnitude of this issue, crumb rubber modifier (CRM obtained from waste tyre rubber has gained interest in asphalt reinforcement. The use of crumb rubber in the reinforcement of asphalt is considered as a smart solution for sustainable development by reusing waste materials, and it is believed that crumb rubber modifier (CRM could be an alternative polymer material in improving hot mix asphalt performance properties. In this paper, a critical review on the use of crumb rubber in reinforcement of asphalt pavement will be presented and discussed. It will also include a review on the effects of CRM on the stiffness, rutting, and fatigue resistance of road pavement construction.

  7. Field Performance of Asphalt Pavements with New Technologies in Northern Nevada

    Science.gov (United States)

    Faeth, Benjamin Michael

    The Regional Transportation Commission (RTC) of the Washoe Valley Area has been tasked to determine if three advanced asphalt pavement technologies and one modified aggregate gradation are suitable for implementation within Reno, Stead, and Sparks Nevada. This was accomplished through research and test roads and Intersections to determine if Recycled Asphalt Pavement (RAP), Warm Mix Asphalt (WMA), Polymer-Modified Asphalt Binder, and the Type 2-R aggregate gradation were succeeding in their design plans. Over the course of several years the streets being used by RTC to test the technologies are succeeding within their design lifespans, and the Intersections being used to test the Type 2-R aggregate gradation are showing significant resistance to rutting. Due to the roads and Intersections not being more than 10 years old, these conclusions are subject to change over time.

  8. Initiation and Propagation Mechanism of Blisters on the Epoxy Asphalt Concrete Paving Course of Steel Deck Bridge Pavement%钢桥面环氧沥青铺装层鼓泡形成扩展机理

    Institute of Scientific and Technical Information of China (English)

    张华; 郝培文; 张海伟

    2016-01-01

    In order to take effective steps to minimize the blistering problems on the epoxy asphalt overlays, the cause and propagation mechanism for blisters were studied systematically by means of field investigation, theoretical analysis and mathematical modeling. Based on the theory of thin plate and fracture mechanics,the deflection of blisters was studied under the pressure. Additionally, the energy principle in fracture mechanics was used to derive the energy relationship and the initiation and propagation mechanism was studied. The results indicate that the development of blisters includes three stages, namely, initiation, stale and unstable propagation. The deflection of blisters produced by the external force was related to the radius of blisters, depth and modulus of elasticity of pavement. The energy release rate was proposed as a criterion of the initiation and propagation of blisters. It provides the theory basis for further model experiment and simulation analysis.%为有效减少钢桥面环氧沥青铺装层出现鼓泡现象,采用现场调查、理论分析和数学建模的研究方法,系统地研究了鼓泡产生的原因和形成扩展机理。基于薄板理论,研究了鼓泡在竖向均布荷载作用下鼓泡挠度的变化规律。根据断裂力学中的能量原理,得到了鼓泡形成扩展过程中的能量关系,进而阐明了鼓泡形成扩展机理。研究结果表明:钢桥面环氧沥青铺装层鼓泡的形成扩展过程分为起裂、稳定扩展和失稳扩展3个阶段;鼓泡在外力作用下产生的挠度与鼓泡半径、铺装层厚度和弹性模量等因素有关,提出了以能量释放率为判定参数的扩展准则。

  9. Feasibility of crumb rubber use for asphalt pavement construction in Rhode Island. Final research report

    Energy Technology Data Exchange (ETDEWEB)

    Lee, K.W.; Kovacs, W.D.; Marcus, A.S.; Madapati, R.R.

    1995-12-15

    This is the final report of the research project, entitled `Viable Use of Crumb Rubber for Highway Construction in Rhode Island.` This study dealt with the investigation of the means by which the State of Rhode Island can effectively comply with the mandate of the Section 1038 of the 1991 Intermodal Surface Transportation Efficiency Act (ISTEA) to use recycled rubber in asphalt pavements. More specifically, this laboratory investigation characterized Hot Mix Asphalt (HMA) with Crumb Rubber Modifiers (CRM).

  10. Forensic study into the causes of premature failures in asphalt pavements in Tanzania

    CSIR Research Space (South Africa)

    Anochie-Boateng, Joseph

    2015-11-01

    Full Text Available . With high volumes of very heavy loading traffic on Tanzanian roads and highways, the use of rut-resistance asphalt mixes such as coarse dense-graded mixes with strong aggregate skeleton should be promoted in Tanzania. 3. In view of the apparent incorrect... of construction, which not only would result in higher levels of densification under traffic, but also could render the mix more susceptible to shear deformation in the early life of the asphalt concrete layer. Not achieving adequate levels of compaction...

  11. Assessment of low temperature cracking in asphalt pavement mixes and rheological performance of asphalt binders

    Science.gov (United States)

    Sowah-Kuma, David

    Government spends a lot of money on the reconstruction and rehabilitation of road pavements in any given year due to various distresses and eventual failure. Low temperature (thermal) cracking, one of the main types of pavement distress, contributes partly to this economic loss, and comes about as a result of accumulated tensile strains exceeding the threshold tensile strain capacity of the pavement. This pavement distress leads to a drastic reduction of the pavement's service life and performance. In this study, the severity of low temperature (thermal) cracking on road pavements selected across the Province of Ontario and its predicted time to failure was assessed using the AASTHO Mechanistic-Empirical Pavement Design Guide (MEPDG) and AASHTOWARE(TM) software, with inputs such as creep compliance and tensile strength from laboratory test. Highway 400, K1, K2, Y1, Sasobit, Rediset LQ, and Rediset WMX were predicted to have a pavement in-service life above 15 years. Additionally, the rheological performance of the recovered asphalt binders was assessed using Superpave(TM) tests such as the dynamic shear rheometer (DSR) and bending beam rheometer (BBR). Further tests using modified standard protocols such as the extended bending beam rheometer (eBBR) (LS-308) test method and double-edge notched tension (DENT) test (LS-299) were employed to evaluate the failure properties associated with in service performance. The various rheological tests showed K1 to be the least susceptible to low temperature cracking compared to the remaining samples whiles Highway 24 will be highly susceptible to low temperature cracking. X-ray fluorescence (XRF) analysis was performed on the recovered asphalt binders to determine the presence of metals such as zinc (Zn) and molybdenum (Mo) believed to originate from waste engine oil, which is often added to asphalt binders. Finally, the severity of oxidative aging (hardening) of the recovered asphalt binders was also evaluated using the

  12. Constructing better roads with asphalt rubber

    Directory of Open Access Journals (Sweden)

    Pais Jorge C.

    2015-12-01

    Full Text Available Brazilians mixtures containing asphalt rubber were evaluated by mechanical laboratory tests. A conventional mixture with asphalt CAP-50/70 was produced as a mixture control. With the aim of compare the Brazilians mixtures performance, a Portuguese asphalt rubber mixture was tested as well. The testing set involved the determination of the mechanical properties, fatigue and permanent deformation, of asphalt rubber produced by wet process through two different systems: continuous blend and terminal blend. The asphalt rubber morphology was evaluated in order to determine the compatibility of the systems. The asphalt rubber mixtures exhibit good resistance to permanent deformation and prolonged fatigue life in relation to mixture control. Therefore it is concluded that the application of asphalt rubber alters the characteristics of asphalt mixture in a very beneficial way.

  13. 混凝土表面硅烷改性后的防腐蚀性能%Corrosion Resistance of Silane Modified Concrete

    Institute of Scientific and Technical Information of China (English)

    刘贵昌; 苏本泽; 王立达; 秦小勇; 徐辉

    2012-01-01

    Silane modification is one of the common techniques used for enhancing the corrosion resistance of carbon steel in concrete, due to the superior penetrability and hydrophobicity of silane. Octyl triethoxysilane(OTES) was taken to modify the concrete surface. The results of IR spectra, contact angle, water absorption and electrochemical tests showed that a hydrophobic layer with water contact angle over 100°was formed on the micropore surface of concrete through the hydrolysis and condensation reactions of silane, resulting in a significant decrease of water absorption and enhancement of corrosion resistance of concrete.%硅烷改性是目前钢筋混凝土结构上常用的防护手段之一。与普通涂料相比,硅烷具有较好的渗透性和疏水性。采用辛基三乙氧基硅烷对混凝土表面改性。通过接触角观察、吸水率测试、电化学测试以及傅立叶红外吸收测试得出:硅烷分子通过水解缩合反应在孔隙壁表面形成有机硅树脂;表面改性后的混凝土疏水效果明显,浸润角大于100°,混凝土吸水率显著降低,扩散阻抗明显增加,混凝土耐蚀性增强。

  14. Floating asphalt blocks of the Dead Sea

    Energy Technology Data Exchange (ETDEWEB)

    Nissenbaum, A. (Weizmann Inst. of Science, Rehovot, Israel); Aizenshtat, Z.; Goldberg, M.

    1980-01-01

    Large blocks of mineral matter free (less than 0.1%) asphalt are occasionally found floating on the surface of the Dead Sea. Chemical, spectroscopic and isotopic data are given for the asphalt. The source of the asphalt is not accurately known, but presumably it represents mobilization of heavy viscous asphaltic masses at depth below the lake bottom into the floor of the lake. It may be released to the surface by earth tremors.

  15. Sinopec Launches Shanghai Asphalt Sales Company

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    @@ Sinopec Shanghai Asphalt Sales Company was launched in Shanghai on September 22, marking Sinopec as the largest asphalt supplier in China integrated in famous brand,production, sales and research, and distribution network.This is another important initiative for Sinopec's asphalt segment, after Sinopec won the bid for construction of F 1 racing course, to grasp the market opportunities, further improve the product quality and the level of after-sales services, and further make its asphalt business larger and stronger.

  16. Evaluation the effect of using polymers on the performance of wearing asphalt mixture

    Directory of Open Access Journals (Sweden)

    Yasir Mohammed Jebur

    2017-03-01

    Full Text Available In Iraq , the increasing in number of vehicles and trucks with their heavy traffic loading and under high temperature , a variety of pavement distresses continues to develop affecting the performance and economy of pavement construction. Polymer modified asphalt mixtures have been used to resist the distresses that produced and developed from the applied stresses. Several distresses effect on the performance of HMA. The primary forms of distress are fatigue cracking , rutting , moisture damage and thermal cracking. These distresses reduce the services life of HMA and increase the maintenance costs. The main objective of this research is to find the effect of polymers on the performance of asphalt mixtureby using one asphalt cement grade (40-50 from Al-Daurah refinery with two types of locally available polymers (Low-Density Polyethylene LDPE and Styrene Butadiene Styrene SBS with three percentages for each type. These percent are (1, 3 and 6 % for (LDPE & SBS by weight of asphalt cement. Each type of these polymers is blended with asphalt cement by using the wet process. The experimental work showed that all polymer-modified mixtures have stability and indirect tensile strength higher than the control mixtures. It can be concluded that the addition of (1% LDPE and (3% SBS to asphalt mixtures showed better improvement on the performance properties of pavement modified with these polymers , in which the referred percent represent the optimum percent of concentration for blending polymers .

  17. How Concrete is Concrete

    OpenAIRE

    2010-01-01

    If we want to make something concrete in mathematics education, we are inclined introduce, what we call, ‘manipulatives’, in the form of tactile objects or visual representations. If we want to make something concrete in a everyday-life conversation, we look for an example. In the former, we try to make a concrete model of our own, abstract, knowledge; in the latter, we try to find an example that the others will be familiar with. This article first looks at the tension between these tw...

  18. 龚家坝隧道温拌沥青混合料路面施工技术%Construction Technology of Warm- mix Asphalt Mixture Pavement in Gongjiaba Tunnel

    Institute of Scientific and Technical Information of China (English)

    李明杰

    2012-01-01

    Through construction on warm - mix asphalt in Gongjiaba tunnel and from the aspects of warm - mix asphalt concrete mixing, paving, compaction by rolling, detection and so on, construction advantages and characters of warm -mix asphalt concrete are introduced.%通过对龚家坝隧道温拌沥青施工,从温拌沥青混凝土拌和、摊铺、碾压、检测等方面,介绍了温拌沥青混凝土的施工优势和特点。

  19. How Concrete is Concrete

    Directory of Open Access Journals (Sweden)

    Koeno Gravemeijer

    2010-07-01

    Full Text Available If we want to make something concrete in mathematics education, we are inclined introduce, what we call, ‘manipulatives’, in the form of tactile objects or visual representations. If we want to make something concrete in a everyday-life conversation, we look for an example. In the former, we try to make a concrete model of our own, abstract, knowledge; in the latter, we try to find an example that the others will be familiar with. This article first looks at the tension between these two different ways of making things concrete. Next another role of manipulatives, will be discussed, namely that of means for scaffolding and communication. In this role, manipulatives may function as means of support in a process that aims at helping students to build on their own thinking while constructing more sophisticated mathematics

  20. Mechanistic and Economical Characteristics of Asphalt Rubber Mixtures

    Directory of Open Access Journals (Sweden)

    Mena I. Souliman

    2016-01-01

    Full Text Available Load associated fatigue cracking is one of the major distress types occurring in flexible pavement systems. Flexural bending beam fatigue laboratory test has been used for several decades and is considered to be an integral part of the new superpave advanced characterization procedure. One of the most significant solutions to prolong the fatigue life for an asphaltic mixture is to utilize flexible materials as rubber. A laboratory testing program was performed on a conventional and Asphalt Rubber- (AR- gap-graded mixtures to investigate the impact of added rubber on the mechanical, mechanistic, and economical attributes of asphaltic mixtures. Strain controlled fatigue tests were conducted according to American Association of State Highway and Transportation Officials (AASHTO procedures. The results from the beam fatigue tests indicated that the AR-gap-graded mixtures would have much longer fatigue life compared with the reference (conventional mixtures. In addition, a mechanistic analysis using 3D-Move software coupled with a cost analysis study based on the fatigue performance on the two mixtures was performed. Overall, analysis showed that AR modified asphalt mixtures exhibited significantly lower cost of pavement per 1000 cycles of fatigue life per mile compared to conventional HMA mixture.