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Sample records for 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. Resonance Testing of Asphalt Concrete

    OpenAIRE

    Gudmarsson, Anders

    2014-01-01

    This thesis present novel non-destructive laboratory test methods to characterize asphalt concrete. The testing is based on frequency response measurements of specimens where resonance frequencies play a key role to derive material properties such as the complex modulus and complex Poisson’s ratio. These material properties are directly related to pavement quality and used in thickness design of pavements. Since conventional cyclic loading is expensive, time consuming and complicated to perfo...

  3. Determination of the asphalt content of the asphalt concrete by surface neutron gauge

    International Nuclear Information System (INIS)

    This paper describes the principle, calibration and field detection of determining the asphalt content of asphalt concrete by surface neutron gauge. This method can be utilized to measure the asphalt content for asphalt concrete dams, highways and airport runways to control the engineering quality

  4. COLOR ASPHALT CONCRETE COATING ON POLIMER-TAR BINDER

    OpenAIRE

    Zolotarev, V.; Golovenchic, S.; Oksak, S.; S. Efremov

    2005-01-01

    The possibility of receiving of color asphalt concrete on polimer-tar binder is found. Principal moments of production technology of coloured mixtures and device of asphalt concrete coating have been revealed.

  5. Multiscale Constitutive Modeling of Asphalt Concrete

    Science.gov (United States)

    Underwood, Benjamin Shane

    Multiscale modeling of asphalt concrete has become a popular technique for gaining improved insight into the physical mechanisms that affect the material's behavior and ultimately its performance. This type of modeling considers asphalt concrete, not as a homogeneous mass, but rather as an assemblage of materials at different characteristic length scales. For proper modeling these characteristic scales should be functionally definable and should have known properties. Thus far, research in this area has not focused significant attention on functionally defining what the characteristic scales within asphalt concrete should be. Instead, many have made assumptions on the characteristic scales and even the characteristic behaviors of these scales with little to no support. This research addresses these shortcomings by directly evaluating the microstructure of the material and uses these results to create materials of different characteristic length scales as they exist within the asphalt concrete mixture. The objectives of this work are to; 1) develop mechanistic models for the linear viscoelastic (LVE) and damage behaviors in asphalt concrete at different length scales and 2) develop a mechanistic, mechanistic/empirical, or phenomenological formulation to link the different length scales into a model capable of predicting the effects of microstructural changes on the linear viscoelastic behaviors of asphalt concrete mixture, e.g., a microstructure association model for asphalt concrete mixture. Through the microstructural study it is found that asphalt concrete mixture can be considered as a build-up of three different phases; asphalt mastic, fine aggregate matrix (FAM), and finally the coarse aggregate particles. The asphalt mastic is found to exist as a homogenous material throughout the mixture and FAM, and the filler content within this material is consistent with the volumetric averaged concentration, which can be calculated from the job mix formula. It is also

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

    OpenAIRE

    Seong-Hyeok Lee; Dae-Wook Park; Hai Viet Vo; Samer Dessouky

    2015-01-01

    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, th...

  7. Surface roughness of an asphalt concrete and its mechanical behavior

    OpenAIRE

    MOMM, L; DE LA ROCHE, C; Domingues, A.

    2003-01-01

    The surface roughness of asphalt concrete is studied according to the maximum aggregate size and to the equation of the aggregate graduation curve, on asphalt concrete plates made in laboratory. The macrotexture increases when the maximum aggregate size increases and it decreases when the aggregate fine contents increases. The asphalt concrete structural behaviour is evaluated with rutting, complex modulus and fatigue tests. The study shows stronger mechanical performances on the asphalt conc...

  8. Determining and Modeling Asphalt Concrete Response (ACRe)

    NARCIS (Netherlands)

    Erkens, S.M.J.G.; Poot, M.R.

    2000-01-01

    In road engineering research and design the principles of material mechanics have not yet become a standard tool. In this contribution a project aimed at applying these principles to asphalt concrete is presented. Attention is paid to the differences between the standard test procedures and those ba

  9. High Modulus Asphalt Concrete with Dolomite Aggregates

    Science.gov (United States)

    Haritonovs, V.; Tihonovs, J.; Smirnovs, J.

    2015-11-01

    Dolomite is one of the most widely available sedimentary rocks in the territory of Latvia. Dolomite quarries contain about 1,000 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, its LA index (The Los Angeles abrasion test). Therefore, mostly the 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 with EN 13108-1 standard.

  10. 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...

  11. Extending the Lifespan of Porous Asphalt Concrete

    OpenAIRE

    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 rejuvenation products on the pavement surfaces are being investigated with high interest in the Netherlands. A material which has the ability to penetrate into the bituminous binder and soften (rejuv...

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. 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.

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

    OpenAIRE

    Yuri KALGIN; Alexander STROKIN

    2016-01-01

    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 an...

  18. 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...

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. Physico-mechanical properties of asphalt concrete based on road bitumen modified by rapeseed oil epoxide

    OpenAIRE

    Nykypanchuk, Mykhailo; Hrynchuk, Yurii; Olchovyk, Mykola

    2013-01-01

    The investigation results of type B fine asphalt concrete and its form modified by rapeseed oil epoxide are represented. The efficiency of ERO addition and its positive effect on the physico-mechanical properties of asphalt concrete has been established.

  4. TECHNOLOGY OF DISPERSED REINFORCEMENT OF ASPHALT CONCRETE MIXTURES WITH CHRYSOTILE FIBRES

    OpenAIRE

    S. I. Buldakov; A. Yu. Dedyukhin

    2010-01-01

    Problem statement. The issues of technology of preparation of dispersed rein-forced asphalt concrete mixtures are still not clearly understood. Available tech-nologies of dispersed reinforcement involve application of granulated additives, which permits the quality of asphalt concrete mixtures to be improved and, there-fore, it will result in increasing life expectancy of asphalt concrete pavements.Results and conclusions. The ways of improvement of quality and durability of asphalt-concrete ...

  5. Comparison of laboratory test performance between asphalt-rubber hot mix and dense graded asphalt concrete

    OpenAIRE

    Sousa, Jorge B.; Pais, Jorge C.; Stubstad, Richard N.

    2000-01-01

    "Reflective cracking in pavements : research in practice" contains the Proceedings of the 4th International RILEM Conference on Reflective Cracking in Pavements (Proceedings PRO11). Asphalt-Rubber Hot-Mix (ARHM) has shown a higher resistance to flexural and reflective fatigue cracking, and also to permanent deformation, than conventional Dense Graded Asphalt Concrete (DGAC). Experience has demonstrated that with ARHM, a significant reduction in overlay thickness is possible, especially in...

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

    OpenAIRE

    Mohammad Saeed Pourtahmasb; Mohamed Rehan Karim

    2014-01-01

    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 t...

  7. An investigation of waste foundry sand in asphalt concrete mixtures.

    Science.gov (United States)

    Bakis, Recep; Koyuncu, Hakan; Demirbas, Ayhan

    2006-06-01

    A laboratory study regarding the reuse of waste foundry sand in asphalt concrete production by replacing a certain portion of aggregate with WFS was undertaken. The results showed that replacement of 10% aggregates with waste foundry sand was found to be the most suitable for asphalt concrete mixtures. Furthermore, the chemical and physical properties of waste foundry sand were analysed in the laboratory to determine the potential effect on the environment. The results indicated that the investigated waste foundry sand did not significantly affect the environment around the deposition PMID:16784170

  8. Asphaltic concrete overlays of rigid and flexible pavements

    Science.gov (United States)

    Kinchen, R. W.; Temple, W. H.

    1980-10-01

    The development of a mechanistic approach to overlay thickness selection is described. The procedure utilizes a deflection analysis to determine pavement rehabilitation needs. Design guides for selecting the overlay thickness are presented. Tolerable deflection-traffic load relationships and the deflection attenuation properties of asphaltic concrete were developed, representing the subgrade support conditions and properties of materials used in Louisiana. All deflection measurements on asphaltic concrete were corrected for the effect of temperature. Deflection measurements taken before and after overlay were also adjusted to minimize the effects of seasonal subgrade moisture variation.

  9. SYSTEM FOR CONTROLLING ELECTRIC DRIVE OF ASPHALT CONCRETE MIXING PLANT

    Directory of Open Access Journals (Sweden)

    A. S. Surmak

    2005-01-01

    Full Text Available It is proposed to evaluate quality of asphalt concrete mixture through definition of current component variable of a drive motor and measurement of its derivative sign. In order to carry out final determination of mixture uniformity a transducer on the basis of a nuclear magnetic resonance is applied. Block diagram of the system is presented and algorithm of its operation is given in the paper. In addition to improvement of the finished product quality the application of the system makes it possible to reduce bitumen consumption used for production of asphalt concrete.

  10. 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.

  11. 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.

  12. 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.

  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. 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

  15. Shakedown analysis of anisotropic asphalt concrete pavements with clay subgrade

    Energy Technology Data Exchange (ETDEWEB)

    Boulbibane, M.; Collins, I.F. [Auckland Univ., Auckland (New Zealand). Dept. of Engineering Science; Weichert, D. [RWTH-Aachen Inst. of General Mechanics, Aachen (Germany); Raad, L. [Alaska-Fairbanks Univ., Fairbanks, AK (United States). Transportation and Research Centre

    2000-08-04

    A mathematical model has been presented which can predict the effect of inherent anisotropic cohesion on the long-term behaviour of multilayered pavements. The model is based on the lower bound theorem of shakedown analysis and makes allowances for variations of soil strength with direction. Pavements operating above the critical shakedown load exhibit plastic strains under long term repeated loading conditions and eventually result in deep ruts. This model was used to examine the influence of subgrade properties on the shakedown behaviour of two-layer pavement systems consisting of an asphalt concrete layer and a granular base over a clay subgrade. The shakedown load for pavements under repeated loadings was estimated and the effects of variables such as temperature, asphalt thickness, stiffness and strength were determined. The materials in the various layers of the pavement were modeled as elastic-plastic Mohr-Coulomb materials. 38 refs., 3 tabs., 5 figs.

  16. Determination of Required Energy Action at Formation of Asphalt Concrete Mixture

    OpenAIRE

    B. M. Khroustalev; V. N. Romaniuok

    2014-01-01

    A problem pertaining to determination of the concentrated exergy of the asphalt concrete mixture is considered in the paper. The paper shows the possibility to use the concentrated exergy of the asphalt concrete mixture for qualitative energy evaluation of mixing processes.

  17. Use of steel slag aggregate in asphalt concrete mixes

    Energy Technology Data Exchange (ETDEWEB)

    Asi, I.M.; Qasrawi, Y.; Shalabi, F.I. [Hashemite Univ., Zarqa (Jordan). Dept. of Civil Engineering

    2007-08-15

    The physical, chemical and mechanical properties of generated steel slag aggregates (SSA) were studied in order to investigate their potential use in asphalt concrete (AC) mixes. Five AC mixes were investigated, notably an AC mix with a 100 per cent limestone aggregate, and mixes comprised of 25, 50, 75, and 100 per cent SSA coarse aggregates. A superpave mix design was used to determine optimum asphalt content (OAC). Steps included the selection of a design aggregate structure, optimization of the asphalt content for the structure, and an evaluation of the moisture sensitivity of the design mixture. The effectiveness of the samples were assessed by their ability to improve indirect tensile strength (ITS); resilient and creep modulus; fatigue life; and stripping and rutting resistance. Various AC mixes containing the SSA were then evaluated. A gyratory compactor was used to compact the test samples, which were then subjected to comprehensive mechanical evaluations. Statistical analyses were then performed to examine the significance of the SSA percentage in the changing ITS values using analysis of variance (ANOVA) calculations. Results of the study indicated that SSA met both superpave consensus properties and Jordanian standards source properties. Chemical and toxic levels were within allowable limits. It was concluded that optimal the replacement percentage of SSA was 25 per cent. 18 refs., 9 tabs., 21 figs.

  18. 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

  19. 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.

  20. 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.

  1. How to transform an asphalt concrete pavement into a solar turbine

    International Nuclear Information System (INIS)

    Highlights: • We create a system for harvesting energy from asphalt concrete. • We create an artificial porosity in the asphalt concrete. • We connect a chimney to this porosity. • Differences in temperature produce an air flow. • This air flow serves also for cooling down the pavement. - Abstract: Asphalt concrete can absorb a considerable amount of the incident solar radiation. For this reason asphalt roads could be used as solar collectors. There have been different attempts to achieve this goal. All of them have been done by integrating pipes conducting liquid, through the structure of the asphalt concrete. The problem of this system is that all pipes need to be interconnected: if one is broken, the liquid will come out and damage the asphalt concrete. To overcome these limitations, in this article, an alternative concept is proposed:parallel air conduits, where air can circulate will be integrated in the pavement structure. The idea is to connect these artificial pore volumes in the pavement to an updraft or to a downdraft chimney. Differences of temperature between the pavement and the environment can be used to create an air flow, which would allow wind turbines to produce an amount of energy and that would cool the pavement down in summer or even warm it up in winter. To demonstrate that this is possible, an asphalt concrete prototype has been created and basics calculations on the parameters affecting the system have been done. It has been found that different temperatures, volumes of air inside the asphalt and the difference of temperature between the asphalt concrete and the environment are critical to maximize the air flow through the pavement. Moreover, it has been found that this system can be also used to reduce the heat island effect

  2. 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 .

  3. 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 .

  4. Effects of compaction method on the properties of asphalt concrete for dams and dykes

    Energy Technology Data Exchange (ETDEWEB)

    Grenier, Simon [Groupe Qualitas Inc., Montreal, (Canada); Konrad, Jean-Marie [University Laval, Quebec, (Canada); Perraton, Daniel [Ecole de technologie superieure, Montreal, (Canada); Peloquin, Eric [Hydro-Quebec, Montreal, (Canada); Longtin, Hugo [SNC-Lavalin, Montreal, (Canada)

    2010-07-01

    Asphalt concrete is used in embankment dams as an impervious lining on the upstream face or in the interior as a core wall. The mix needs to be compacted to a specific density to ensure low permeability, ductility and flexibility of the materiel. This paper investigated the influence of three compaction methods on the stress-strain curves and the strength of the asphalt concrete mixture. Comparisons between laboratory and field compaction methods of asphalt concrete mix with high bitumen content were carried out. Triaxial tests results on samples from the Nemiscau-1 Dam constructed in 2008 in Quebec, Canada and on laboratory-compacted asphalt concrete samples were compared. The results showed that the differences between materials can be explained by the specific aggregate structure obtained for each compaction method, which results in preferential grain orientation and in more or less interlocking between grains.

  5. 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...

  6. 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.

  7. Permanent Deformation of Asphalt Concrete Pavements: A Nonlinear Viscoelastic Approach to Mix Analyses and Design

    OpenAIRE

    Long, Fenella Margare

    2001-01-01

    Because pavements are being subjected to increasingly heavy loads, many mix design procedures currently in use may not adequately prevent permanent deformation (rutting) in asphalt concrete. This dissertation describes the development of a nonlinear viscoelastic constitutive model that can be used in mix analyses to design rut-resistant mixes. Shear deformation is the dominant cause of rutting in asphalt concrete, a nonlinear viscoelastic material. To determine the viscoelastic shear...

  8. 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. PMID:17408942

  9. Utilization of Recycled Concrete Aggregates in Stone Mastic Asphalt Mixtures

    Directory of Open Access Journals (Sweden)

    Mohammad Saeed Pourtahmasb

    2014-01-01

    Full Text Available Recycled concrete aggregate (RCA is considered as one of the largest wastes in the entire world which is produced by demolishing concrete structures such as buildings, bridges, and dams. It is the intention of scientists and researchers, as well as people in authority, to explore waste material recycling for environmental and economic advantages. The current paper presents an experimental research on the feasibility of reusing RCA in stone mastic asphalt (SMA mixtures as a partial replacement of coarse and fine aggregates. The engineering properties of SMA mixtures containing RCA have been evaluated for different percentages of binders based on the Marshall mix design method. The outcomes were statistically analyzed using two-factor analysis of variance (ANOVA. Test results revealed that the performance of SMA mixtures is affected by RCA due to higher porosity and absorption of RCA in comparison with virgin granite aggregates. However, the engineering properties of SMA mixtures containing a particular amount of RCA showed the acceptable trends and could satisfy the standard requirements. Moreover, to achieve desirable performance characteristics, more caution should be made on properties of SMA mixtures containing RCA.

  10. 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.

  11. Analyzing the influence of manufacturing conditions of reclaimed asphalt concrete on the characteristics of the asphalt binder: development of a gradual binder extraction method

    Science.gov (United States)

    Navaro, J.; Bruneau, D.; Drouadaine, I.; Pouteau, B.; Colin, J.; Dony, A.

    2012-05-01

    When asphalt concrete is manufactured incorporating a high percentage (almost 70%) of reclaimed materials from the deconstruction of road surfaces under renovation, and when the corresponding production device is designed specifically to reduce the energy input need (lowering the production temperature), the resulting manufacturing process contributes to the protection of the environment and reduces production costs. However, to meet the quality requirements of the finished product, virgin materials of appropriate quality and quantity must also be added (mineral aggregates and new asphalt binder) and control systems set up to quantify and optimize the parameters involved (thus avoiding the guess work which still often prevails today). It was for this reason that a new experimental technique described here was devised, which will ultimately be used in asphalt concrete production plants. The technique involves lixiviating reclaimed asphalt concrete using a chlorinated solvent; the resulting solute is collected gradually, then the mixture of binders (virgin and reclaimed asphalt concrete) can be characterized and their mass fractions quantified using a combination of UV and IR spectrometry. With this experimental technique we were able to assess the extent to which the reclaimed asphalt pavement binder participates in the agglomeration and cohesion of the reclaimed asphalt concrete. This assessment was made in terms of the main parameters in the production process, temperature of the materials and mixing time.

  12. An optimized setup for determining the bitumen content in asphalt concrete by the neutron reflection method

    International Nuclear Information System (INIS)

    A setup was developed in order to determine the bitumen content in asphalt concrete by neutron reflection. The main parts of this setup are an Am-Be neutron source of 37 GBq and a 3He neutron detector. To avoid geometrical effects of the measurements, the optimum volume of the samples was determined by plotting the reflected neutron response versus the sample volume. For the calibration of the system, the American Standard Method (ASTM) was used when preparing aggregate and asphalt concrete samples. The method was then compared to the conventional chemical method by analyzing unknown samples taken from an asphalt concrete producing plant and finally the method was assessed in terms of reproducibility, sensitivity and precision. (author)

  13. 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.

  14. Determination of the bitumen content in asphalt concrete using a neutron reflection method

    International Nuclear Information System (INIS)

    A neutron physical method (reflection method) for the fast, nondestructive determination of the bitumen content in asphalt concrete has been developed. The determination is performed on cylindrical asphalt concrete samples containing desiccated rubble matrix. Using samples of about 1000g and measuring times of 20 min, the reproducibility of the bitumen determination is 0.15 w%, the sensitivity is 3.10-3 g/g. The thus obtained results were compared with data obtained by chemical analysis, using two different type of matrix. The mean values and the standard deviations are in good agreement for both cases. (T.G.)

  15. Self-monitoring Application of Asphalt Concrete Containing Graphite and Carbon Fibers

    Institute of Scientific and Technical Information of China (English)

    LIU Xiaoming; WU Shaopeng; LI Ning; GAO Bo

    2008-01-01

    The self-monitoring application of asphalt concrete containing graphite and carbon fibers using indirect tensile test and wheel rolling test were introduced. The experiment results indicate that this kind of pitch-based composite is effective for strain/stress self-monitoring. In the indirect tensile test, for a completely conductive asphalt concrete specimen, the piezoresistivity was very weak and slightly positive,which meant the resistivity increase with the increment of tensile strain at all stress/strain amplitudes, with the gage factor as high as 6. The strain self-sensing ability was superior in the case of higher graphite content.However, when the conductive concrete was embedded into common asphalt concrete specimen as a partial structure function, the piezoresistivity was positive at all stress/strain amplitudes and with the gage factor of 13,which was much higher than that of completely conductive specimen. Thus, the strain self-sensing ability was superior when conductive asphalt concrete was taken in as a partial structure function. In the wheel-rolling test,the piezoresistivity was highly positive. At any stress amplitude, the piezoresistivity was strong, with the gage factor as high as 100, which was higher for a stress amplitude of 0.7 MPa than that of 0.5 MPa.

  16. 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. PMID:22897427

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

    Directory of Open Access Journals (Sweden)

    D. I. Chernousov

    2011-11-01

    Full Text Available 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 modulus of elasticity and tensile bending strength. To forecast operating properties ofasphalt concrete, 4×4×16 cm beams were tested on vibrostand УВ 70/100, which enables one toobtain frequency and amplitude of oscillations continuously adjustable during operation. The techniqueuses analytical relationships which allow one to determine durability of operating period undersimulation of axis load of 6 and 10 tons. Comparison of the relationships obtained shows thatmodulus of elasticity, bending and comparison strength of involved asphalt concrete mixes markedlydecrease. However, this decrease is more pronounced with reference asphalt concretes.Conclusions. The use of shungite mineral powder provides for increasing fatigue life of asphaltconcrete, which can be related to higher adhesion activity of shungite powder compared with limestonepowder.

  18. 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 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.

  19. 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.

    2016-04-01

    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. In this paper, a four level multiscale computational micromechanics methodology is utilized to determine the accuracy of micromechanics versus directly measured viscoelastic properties of asphalt concrete pavement. This is accomplished by first measuring the viscoelastic dynamic modulus of asphalt binder, as well as the elastic properties of the constituents, and this comprised the first scale analysis. In the second scale analysis, the finite element method is utilized to predict the effect of mineral fillers on the dynamic modulus. In the third scale analysis, the finite element method is again utilized to predict the effect of fine aggregates on the dynamic modulus. In the fourth and final scale analysis, the finite element method is utilized to predict the effect of large aggregates on the dynamic modulus of asphalt concrete. This final predicted result is then compared to the experimentally measured dynamic modulus of two different asphalt concretes for various volume fractions of the constituents. Results reveal that the errors in predictions are on the order of 60 %, while the ranking of the mixtures was consistent with experimental results. It should be noted that differences between the "final predicted results" and the experimental results can provide fruitful ground for understanding the effect of interactions not considered in the multiscale approach, most importantly, chemical interactions.

  20. Advanced methodology for optimization of mixture design of asphalt concrete containing reclaimed asphalt pavement material

    OpenAIRE

    Bressi, Sara

    2016-01-01

    Despite the massive use of Reclaimed Asphalt Pavement (RAP) in Hot Mix Asphalt (HMA) production, the chemo-physical phenomena that characterise the fabrication of these mixtures have not yet been completely explored. The detection and understanding of these mechanisms as well as the study of the heterogeneity that characterizes high RAP mix production are fundamental to improving the approach to recycling, because they represent the source of the mixture characteristics and performance. This...

  1. Development of high stability hot mix asphalt concrete with hybrid binder

    Directory of Open Access Journals (Sweden)

    Toshiaki Hirato

    2014-12-01

    Full Text Available Cost reduction of public works projects has been desired due to severe financial circumstances. Therefore, asphalt pavement has been requested to extend its life. Semi-flexible pavement or epoxy asphalt pavement, which has high rutting resistance and oil resistance, may be applied to the place where these performances ae demanded. However, special technique is required in manufacturing and construction. In addition, these materials have also raised a problem that they cannot be recycled. Meanwhile, conventional asphalt pavement has several drawbacks. It is vulnerable to rutting caused by traffic load and damage caused by petroleum oils such as gasoline or motor oil. The materials used in asphalt mixtures were studied for improving the durability of asphalt mixture. A high stability asphalt concrete was developed which has equal or superior performance to semi-flexible pavement and epoxy asphalt pavement. In this paper, the process of selecting the substance and the characteristics evaluation of the developed mixtures ae described. Furthermore, an inspection result as well as follow-up survey of the performance of the developed mixtures obtained from trial and actual construction is shown.

  2. 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.

  3. Modelling of Mechanical Properties of Cement Concrete Incorporating Reclaimed Asphalt Pavement

    OpenAIRE

    MATHIAS, Vincent; SEDRAN, Thierry; De Larrard, François

    2009-01-01

    In many countries there is a trend to recycle wastes obtained during pavement maintenance or reconstruction, and to forbid the landfill of these products. Thus, in some circumstances it can be tempting to use reclaimed asphalt pavement (RAP) in new hydraulic concrete mixtures. This paper presents experimental data and modelling about the effect of RAP incorporation on cement concrete mechanical properties (compressive strength, tensile strengths and E-modulus). All these properties tend to de...

  4. A Multiscale Virtual Fabrication and Lattice Modeling Approach for the Fatigue Performance Prediction of Asphalt Concrete

    Science.gov (United States)

    Dehghan Banadaki, Arash

    Predicting the ultimate performance of asphalt concrete under realistic loading conditions is the main key to developing better-performing materials, designing long-lasting pavements, and performing reliable lifecycle analysis for pavements. The fatigue performance of asphalt concrete depends on the mechanical properties of the constituent materials, namely asphalt binder and aggregate. This dependent link between performance and mechanical properties is extremely complex, and experimental techniques often are used to try to characterize the performance of hot mix asphalt. However, given the seemingly uncountable number of mixture designs and loading conditions, it is simply not economical to try to understand and characterize the material behavior solely by experimentation. It is well known that analytical and computational modeling methods can be combined with experimental techniques to reduce the costs associated with understanding and characterizing the mechanical behavior of the constituent materials. This study aims to develop a multiscale micromechanical lattice-based model to predict cracking in asphalt concrete using component material properties. The proposed algorithm, while capturing different phenomena for different scales, also minimizes the need for laboratory experiments. The developed methodology builds on a previously developed lattice model and the viscoelastic continuum damage model to link the component material properties to the mixture fatigue performance. The resulting lattice model is applied to predict the dynamic modulus mastercurves for different scales. A framework for capturing the so-called structuralization effects is introduced that significantly improves the accuracy of the modulus prediction. Furthermore, air voids are added to the model to help capture this important micromechanical feature that affects the fatigue performance of asphalt concrete as well as the modulus value. The effects of rate dependency are captured by

  5. Numerical simulation of wave attack on sea dike with asphalt concrete revetment

    NARCIS (Netherlands)

    Jassim, I.; Tan, S.; Vermeer, P.A.; Hicks, M.A.

    2012-01-01

    The numerical simulation of wave attack on a sea dike with an asphalt concrete revetment during a severe storm is carried out using the dynamic Finite Element Method. When wave loads attack the revetment during such a storm, both the revetment and the underlying soil may be damaged. The two-phase fl

  6. 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

  7. 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

  8. Improved set-up for determination of bitumen content in asphalt concrete by the neutron reflection method

    International Nuclear Information System (INIS)

    A set-up was developed for the determination of bitumen in asphalt concrete by the neutron reflection method. The main parts of this set-up include an Am-Be neutron source (1 Ci) and a 3He neutron detector. To avoid geometrical effects on the measurements, the optimum sample volume was determined from the neutron response vs volume sample plot. The AST method (ASTM) was used for calibration when preparing the aggregate and asphalt concrete samples. The method was compared to the conventional chemical method by analysing unknown samples taken from the asphalt concrete producing plant. The method was characterized by its reproducibility, sensitivity and precision

  9. 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.

  10. 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.

  11. Experimental investigation of the fatigue behaviour of asphalt concrete mixtures containing waste iron powder

    International Nuclear Information System (INIS)

    Research highlights: → This paper presents the first model of the fatigue behaviour of iron-asphalt mixtures in the world. → This model is able to describe the fatigue behaviour of iron-asphalt under dynamic loading. → Coarse surface, high stiffness and angularity of iron powder lead to enhanced fatigue performance. → The model illustrates that the use of iron powder has a considerable effect on tensile strain of HMA. → The use of this type of waste material could be a helpful solution for less polluted environment. - Abstract: The use of additives and admixtures in the construction of asphalt concrete pavements to strengthen them against dynamic loads has increased considerably in recent years. Recent research has shown that employing desirable waste materials in hot mix asphalts (HMAs) improves their dynamic properties noticeably. The study of some special cases, such as the addition of blast furnace slag and metallic materials of waste electronic instruments to HMA, has led to a considerable increase in the ability of HMAs to tolerate fatigue phenomena and repeated loading. Based on experimental studies, a model is proposed to describe the fatigue behaviour of asphalt mixtures containing waste iron powder. The results of this research show an important increase in the strength of asphalt mixtures containing waste iron powder against fatigue phenomena in comparison to conventional HMAs.

  12. 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. PMID:25574851

  13. Predicting the behavior of asphalt concrete pavements in seasonal frost areas using nondestructive techniques

    Science.gov (United States)

    Janoo, Vincent C.; Berg, Richard L.

    1990-11-01

    Four different pavement test sections were subjected to freeze-thaw cycling in the Frost Effects Research Facility (FERF). The test sections, each 610 cm in length, consisted of 15.2 cm of asphalt concrete pavement over a clay subgrade; 15.2 cm of asphalt concrete over 10.2 cm of crushed gravel over a clay subgrade; 5.1 cm of asphalt over 17.8 cm of crushed gravel over 20.3 cm of clean sand over a clay subgrade; and 5.1 cm of asphalt concrete over 25.4 cm of crushed gravel over 12.7 cm of clean sand over clay subgrade. Thermocouples were imbedded throughout the pavement structure and subgrade. During the thawing periods, deflection measurements were made at four locations in each test section using a Dynatest Falling Weight Deflectometer (FWD). The results of the deflection measurement are presented here. An analysis was done to qualify the subgrade strength based solely on FDW measurements. It was also shown that a relationship existed between thaw depth and FWD measurement in the subgrade.

  14. 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. PMID:24316812

  15. 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.

  16. 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.

  17. Continuous relaxation and retardation spectrum method for viscoelastic characterization of asphalt concrete

    Science.gov (United States)

    Bhattacharjee, Sudip; Swamy, Aravind Krishna; Daniel, Jo S.

    2012-08-01

    This paper presents a simple and practical approach to obtain the continuous relaxation and retardation spectra of asphalt concrete directly from the complex (dynamic) modulus test data. The spectra thus obtained are continuous functions of relaxation and retardation time. The major advantage of this method is that the continuous form is directly obtained from the master curves which are readily available from the standard characterization tests of linearly viscoelastic behavior of asphalt concrete. The continuous spectrum method offers efficient alternative to the numerical computation of discrete spectra and can be easily used for modeling viscoelastic behavior. In this research, asphalt concrete specimens have been tested for linearly viscoelastic characterization. The linearly viscoelastic test data have been used to develop storage modulus and storage compliance master curves. The continuous spectra are obtained from the fitted sigmoid function of the master curves via the inverse integral transform. The continuous spectra are shown to be the limiting case of the discrete distributions. The continuous spectra and the time-domain viscoelastic functions (relaxation modulus and creep compliance) computed from the spectra matched very well with the approximate solutions. It is observed that the shape of the spectra is dependent on the master curve parameters. The continuous spectra thus obtained can easily be implemented in material mix design process. Prony-series coefficients can be easily obtained from the continuous spectra and used in numerical analysis such as finite element analysis.

  18. 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.

  19. Investigation of statistical relationship between dynamic modulus and thermal strength of asphalt concrete

    International Nuclear Information System (INIS)

    Dynamic modulus is a performance indicator for asphalt concrete and is used to qualify asphalt mixtures based on stress-strain characteristics under repeated loading. Moreover, the low temperature cracking of asphalt concrete mixes are measured in terms of fracture strength and fracture temperature. Dynamic modulus test was selected as one of the simple performance tests in the AASHTO 2002 guidelines to rate mixtures according to permanent deformation performance. However, AASHTO 2002 guidelines is silent in relating dynamic modulus values to low temperature cracking, probably because of weak correlations reported between these two properties. The present study investigates the relation between these two properties under the influence of aggregate type and mix gradation. Mixtures were prepared with two types of aggregate and gradations, while maintaining the binder type and air voids constant. The mixtures were later tested for dynamic modulus and fracture strength using thermal stress restrained specimen test (TSRST). Results indicate that there exists a fair correlation between the thermal fracture strength and stiffness at a selected test temperature and frequency level. These correlations are highly dependent upon the type of aggregate and mix gradation. (author)

  20. Characterization of Various Plant-Produced Asphalt Concrete Mixtures Using Dynamic Modulus Test

    Directory of Open Access Journals (Sweden)

    Muhammad Irfan

    2016-01-01

    Full Text Available This research characterizes the performance of various plant-produced asphalt concrete mixtures by dynamic modulus |E∗| test using asphalt mixture performance tester (AMPT. Marshall designed specimens of seven different mixtures were prepared using the Superpave gyratory compactor and subjected to sinusoidal compressive loading at various temperatures (4.4 to 54.4°C and loading frequencies (0.1 to 25 Hz. A catalog of default dynamic modulus values for typical asphalt concrete mixtures of Pakistan was established by developing stress-dependent master curves separately, for wearing and base course mixtures. The sensitivity of temperature and loading frequency on determination of dynamic modulus value was observed by typical isothermal and isochronal curves, respectively. Also, the effects of various variables on dynamic modulus were investigated using statistical technique of two-level factorial design of experiment. Furthermore, two dynamic modulus prediction models, namely, Witczak and Hirsch, were evaluated for their regional applicability. Results indicated that both the Witczak and Hirsch models mostly underpredict the value of dynamic modulus for the selected conditions/mixtures. The findings of this study are envisaged to facilitate the implementation of relatively new performance based mechanistic-empirical structural design and analysis approach.

  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. 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.

  3. Value-added utilisation of recycled concrete in hot-mix asphalt

    International Nuclear Information System (INIS)

    The feasibility of partial substitution of granite aggregate in hot-mix asphalt (HMA) with waste concrete aggregate was investigated. Three hybrid HMA mixes incorporating substitutions of granite fillers/fines with 6%, 45% untreated, and 45% heat-treated concrete were evaluated by the Marshall mix design method; the optimum binder contents were found to be 5.3%, 6.5% and 7.0% of grade Pen 60/70 bitumen, respectively. All three hybrid mixes satisfied the Marshall criteria of the Singapore Land Transport Authority (LTA) W3B wearing course specification. The hybrid mix with 6% concrete fillers gave comparable resilient modulus and creep resistance as the conventional W3B mix, while hybrid mixes with higher concrete substitutions achieved better performance. X-ray diffraction (XRD) showed the distinct presence of free lime in the heat-treated concrete, while the scanning electron microscope (SEM) provided an in-depth perspective of the concrete grains in the HMA matrix. The results suggest feasible use of waste concrete as partial aggregate substitution in HMA

  4. Value-added utilisation of recycled concrete in hot-mix asphalt.

    Science.gov (United States)

    Wong, Yiik Diew; Sun, Darren Delai; Lai, Dickson

    2007-01-01

    The feasibility of partial substitution of granite aggregate in hot-mix asphalt (HMA) with waste concrete aggregate was investigated. Three hybrid HMA mixes incorporating substitutions of granite fillers/fines with 6%, 45% untreated, and 45% heat-treated concrete were evaluated by the Marshall mix design method; the optimum binder contents were found to be 5.3%, 6.5% and 7.0% of grade Pen 60/70 bitumen, respectively. All three hybrid mixes satisfied the Marshall criteria of the Singapore Land Transport Authority (LTA) W3B wearing course specification. The hybrid mix with 6% concrete fillers gave comparable resilient modulus and creep resistance as the conventional W3B mix, while hybrid mixes with higher concrete substitutions achieved better performance. X-ray diffraction (XRD) showed the distinct presence of free lime in the heat-treated concrete, while the scanning electron microscope (SEM) provided an in-depth perspective of the concrete grains in the HMA matrix. The results suggest feasible use of waste concrete as partial aggregate substitution in HMA. PMID:16564163

  5. Viscoelastic micromechanical model for dynamic modulus prediction of asphalt concrete with interface effects

    Institute of Scientific and Technical Information of China (English)

    董满生; 高仰明; 李凌林; 王利娜; 孙志彬

    2016-01-01

    A viscoelastic micromechanical model is presented to predict the dynamic modulus of asphalt concrete (AC) and investigate the effect of imperfect interface between asphalt mastic and aggregates on the overall viscoelastic characteristics of AC. The linear spring layer model is introduced to simulate the interface imperfection. Based on the effective medium theory, the viscoelastic micromechanical model is developed by two equivalence processes. The present prediction is compared with available experimental data to verify the developed framework. It is found that the proposed model has the capability to predict the dynamic modulus of AC. Interface effect on the dynamic modulus of AC is discussed using the developed model. It is shown that the interfacial bonding strength has a significant influence on the global mechanical performance of AC, and that continued improvement in surface functionalization is necessary to realize the full potential of aggregates reinforcement.

  6. 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. PMID:16426748

  7. 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

  8. 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.

  9. Use of plastic waste (poly-ethylene terephthalate) in asphalt concrete mixture as aggregate replacement.

    Science.gov (United States)

    Hassani, Abolfazl; Ganjidoust, Hossein; Maghanaki, Amir Abedin

    2005-08-01

    One of the environmental issues in most regions of Iran is the large number of bottles made from poly-ethylene terephthalate (PET) deposited in domestic wastes and landfills. Due to the high volume of these bottles, more than 1 million m3 landfill space is needed for disposal every year. The purpose of this experimental study was to investigate the possibility of using PET waste in asphalt concrete mixes as aggregate replacement (Plastiphalt) to reduce the environmental effects of PET disposal. For this purpose the mechanical properties of plastiphalt mixes were compared with control samples. This study focused on the parameters of Marshall stability, flow, Marshall quotient (stability-to-flow ratio) and density. The waste PET used in this study was in the form of granules of about 3 mm diameter which would replace (by volume) a portion of the mineral coarse aggregates of an equal size (2.36-4.75 mm). In all prepared mixes the determined 6.6% optimum bitumen content was used. In this investigation, five different percentages of coarse aggregate replacement were used. The results showed that the aggregate replacement of 20% by volume with PET granules would result in a reduction of 2.8% in bulk compacted mix density. The value of flow in the plastiphalt mix was lower than that of the control samples. The results also showed that when PET was used as partial aggregate replacement, the corresponding Marshall stability and Marshall quotient were almost the same as for the control samples. According to most of specification requirement, these results introduce an asphalt mix that has properties that makes it suitable for practical use and furthermore, the recycling of PET for asphalt concrete roads helps alleviate an environmental problem and saves energy. PMID:16200982

  10. 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.

  11. 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.

  12. Evaluation of new nuclear density gauges on asphalt concrete. Final report, Oct 87-Jun 90

    International Nuclear Information System (INIS)

    The report documents an evaluation of the state-of-the-art capabilities of nuclear density gauges to monitor the density of asphalt concrete. In particular, providing immediate information on compaction by the use of roller-mounted gauges and measuring the densities of thin layers were addressed. The study included three phases: literature search, laboratory tests, and field trials. The first phase included a review of current literature on the theory and operating characteristics of commercially available equipment and a review of State highway agency procedures and specifications for monitoring asphalt concrete density. The second phase included a series of laboratory tests to verify factory calibrations and to determine the depth sensitivity, chemical composition errors, and thin-lift capabilities of the various gauges under laboratory conditions. The third phase consisted of five sets of field trials. The data show that, within limitations, static nuclear gauges can be used for acceptance testing of thin-lifts, but only when all parameters affecting the measurements are precisely known. The dynamic gauges can be effectively used to monitor relative density growth

  13. Linear viscoelastic limits of asphalt concrete at low and intermediate temperatures

    Science.gov (United States)

    Mehta, Yusuf A.

    The purpose of this dissertation is to demonstrate the hypothesis that a region at which the behavior of asphalt concrete can be represented as a linear viscoelastic material can be determined at low and intermediate temperatures considering the stresses and strains typically developed in the pavements under traffic loading. Six mixtures containing different aggregate gradations and nominal maximum aggregate sizes varying from 12.5 to 37.5 mm were used in this study. The asphalt binder grade was the same for all mixtures. The mixtures were compacted to 7 +/- 1% air voids, using the Superpave Gyratory Compactor. Tests were conducted at low temperatures (-20°C and -10°C), using the indirect tensile test machine, and at intermediate temperatures (4°C and 20°C), using the Superpave shear machine. To determine the linear viscoelastic range of asphalt concrete, a relaxation test for 150 s, followed by a creep test for another 150 s, was conducted at 150 and 200 microstrains (1 microstrain = 1 x 10-6), at -20°C, and at 150 and 300 microstrains, at -10°C. A creep test for 200 s, followed by a recovery test for another 200 s, was conducted at stress levels up to 800 kPa at 4°C and up to 500 kPa at 20°C. At -20°C and -10°C, the behavior of the mixtures was linear viscoelastic at 200 and 300 microstrains, respectively. At intermediate temperatures (4°C and 20°C), an envelope defining the linear and nonlinear region in terms of stress as a function of shear creep compliance was constructed for all the mixtures. For creep tests conducted at 20°C, it was discovered that the commonly used protocol to verify the proportionality condition of linear viscoelastic behavior was unable to detect the appearance of nonlinear behavior at certain imposed shear stress levels. Said nonlinear behavior was easily detected, however, when checking the satisfaction of the superposition condition. The envelope constructed for determining when the material becomes nonlinear should be

  14. 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.

    2016-03-01

    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. In this work, a recent performance oriented study of this innovative approach to prove the feasibility of the healing concept at large scale is presented. This work was focused on the analysis of 1.8 m long test slabs damaged by the Model Mobile Load Simulator MMLS3. It is known that visible cracks cannot be completely healed by this technique and therefore, recovery of the mechanical performance is not significant. For this reason, inductive heating must be applied not later than the initiation of micro-cracks to allow them to be promptly closed avoiding their propagation. In order to monitor the damage level of a number of the test slabs during the loading phase, a digital image correlation system was used in this work. This optical method allowed us to see the accumulated damage as well as to select the right moment to accomplish the healing process. In addition, this method was useful to confirm that the strength was recovered after a healing process and hence, an increase of life of the asphalt pavement might be obtained. Finally, it was demonstrated that healing by induction heating can be a feasible alternative for maintenance purposes when used before irreversible damage of the pavement.

  15. 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.

  16. 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

  17. Investigation of Primary Causes of Load-Related Cracking in Asphalt Concrete Pavement in North Carolina

    Science.gov (United States)

    Park, Hong Joon

    This dissertation presents causes of cracking in asphalt concrete pavement in North Carolina through field investigation and laboratory experiments with field extracted material. North Carolina is experiencing higher than anticipated rates of fatigue cracking compared to other state. These higher than expected rates could be reflective of the national trends in mix design practice or could be caused by structural pavement failures. The problems associated with premature cracking in North Carolina pavements point to the need to evaluate the North Carolina Department of Transportation (NCDOT) mixes, processes, and measures to ensure that these factors properly balance the goals of preventing cracking and minimizing permanent deformation. Without solid data from in-service pavements, any conclusions regarding the causes of these failures might be pure conjecture. Accordingly, this research examines material properties through laboratory experiments using field-extracted materials and investigates in situ pavements and pavement structure. In order to assess condition of existing pavement, alligator cracking index (ACI) was developed. The asphalt content in the top layer that exhibits top-down cracking or bottom-up cracking has a proportional relationship to ACI values. The air void content in a bottom layer that exhibits top-down cracking or bottom-up cracking shows an inverse proportional relationship to ACI values. These observations reflect reasonable results. A comparison between ACI and asphalt film thickness values does not produce noteworthy findings, but somewhat reasonable results are evident once the range of comparison is narrowed down. Thicker film thicknesses show higher ACI values. From field core visual observations, road widening is identified as a major cause of longitudinal cracking. Regions with observed layer interface separation tend to have low ACI values. Through tensile strain simulation based on actual field conditions, it is observed that

  18. Effect of the constituents (asphalt, clay materials, floating particles and fines) of construction and demolition waste on the properties of recycled concretes

    OpenAIRE

    Medina Martínez, César; Zhu, W; Howind, T.; Frías Rojas, Moisés; Sánchez de Rojas, María Isabel

    2015-01-01

    The present study explores the viability of reusing mixed recycled aggregate from construction and demolition waste as a partial (25 and 50 wt%) replacement for natural coarse aggregate in the manufacture of concretes with a compressive strength of 30 MPa. It further analyses the effect of some of the constituents (asphalt, clay-based materials, floating particles and fines) of these recycled aggregates on the properties of recycled concretes. Despite the high asphalt and floating...

  19. 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.

  20. 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。

  1. 谈橡胶沥青混凝土施工工艺%Talking about the construction technology of rubber asphalt concrete

    Institute of Scientific and Technical Information of China (English)

    白潇娟

    2012-01-01

    理论联系实际介绍了橡胶沥青混凝土抗压、减噪、成本低等优点,并从橡胶沥青混凝土的应用、拌制等方面简浅的论述了橡胶沥青混凝土的施工工艺,较好地解决了现场可能出现的问题,为沥青混凝土路面施工创造了更好的条件。%This article theoretically and practically introduces advantages of rubber asphalt from aspects of rubber asphalt concrete compression,noise-reduction,and low cost and so on,discusses the construction technology of rubber asphalt concrete from the application and mixing,which avoids possible problems and creates better conditions for the construction of asphalt concrete pavement.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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. PMID:20566237

  8. 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.

  9. 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.

  10. 提高沥青混凝土均匀性的主要措施%Main Measures to Improve Homogeneity of Asphalt Concrete

    Institute of Scientific and Technical Information of China (English)

    陶涛

    2014-01-01

    The heterogeneity of asphalt concrete is an important cause of pavement damage. Given this, the paper discusses the significance and measures of advancing the management of raw materials, asphalt concrete mixing plant, transport and construction site to heightening the homogeneity of asphalt concrete, which can be consulted by peers.%沥青混凝土的不均匀性是引起路面破坏的重要原因。鉴于此,探讨了加强对原材料、沥青混凝土拌和厂、运输与施工现场的管理对提高沥青混凝土均匀性的重要意义和具体措施,可供同行参考。

  11. 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.

  12. 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。

  13. Time resolved analysis of water drainage in porous asphalt concrete using neutron radiography

    International Nuclear Information System (INIS)

    Porous asphalt as a road surface layer controls aquaplaning as rain water can drain through its highly porous structure. The process of water drainage through this permeable layer is studied using neutron radiography. Time-resolved water configuration and distribution within the porous structure are reported. It is shown that radiography depicts the process of liquid water transport within the complex geometry of porous asphalt, capturing water films, filled dead end pores and water islands. - Highlights: ► The water drainage process in porous asphalt was studied using neutron radiography. ► Despite similar mix designs, different processes of water transport were established. ► Water transport within porous asphalt showed filled dead end pores and water islands

  14. 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.

  15. 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.

  16. Time resolved analysis of water drainage in porous asphalt concrete using neutron radiography.

    Science.gov (United States)

    Poulikakos, L D; Sedighi Gilani, M; Derome, D; Jerjen, I; Vontobel, P

    2013-07-01

    Porous asphalt as a road surface layer controls aquaplaning as rain water can drain through its highly porous structure. The process of water drainage through this permeable layer is studied using neutron radiography. Time-resolved water configuration and distribution within the porous structure are reported. It is shown that radiography depicts the process of liquid water transport within the complex geometry of porous asphalt, capturing water films, filled dead end pores and water islands.

  17. Time resolved analysis of water drainage in porous asphalt concrete using neutron radiography.

    Science.gov (United States)

    Poulikakos, L D; Sedighi Gilani, M; Derome, D; Jerjen, I; Vontobel, P

    2013-07-01

    Porous asphalt as a road surface layer controls aquaplaning as rain water can drain through its highly porous structure. The process of water drainage through this permeable layer is studied using neutron radiography. Time-resolved water configuration and distribution within the porous structure are reported. It is shown that radiography depicts the process of liquid water transport within the complex geometry of porous asphalt, capturing water films, filled dead end pores and water islands. PMID:23500651

  18. 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。

  19. 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.

  20. 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

  1. 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

    2016-03-01

    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. For the rheological characterization, three-point bending creep tests are performed on beams of different sizes. The beams are also analyzed using digital image analysis to obtain volumetric fraction, average size distribution, and spatial correlation functions. Based on the experimental results and analyses, it is concluded that representative creep stiffness values of asphalt mixtures can be obtained from testing at least three replicates of the thin (BBR) mixture beams. Failure properties are investigated by performing strength tests using a modified Bending Beam Rheometer (BBR), capable of applying loads at different loading rates. Histogram testing of BBR mixture beams and of larger beams is performed and the failure distribution is analyzed based on the size effect theory for quasibrittle materials. Different Weibull moduli are obtained from the two specimens sizes, which indicates that BBR beams do not capture the representative volume element (RVE) of the material.

  2. 橡胶沥青混凝土路面施工技术研究%Research on construction technology of rubber asphalt concrete pavement

    Institute of Scientific and Technical Information of China (English)

    李霞

    2015-01-01

    对传统路面与橡胶混凝土路面的性价比进行了分析比较,介绍了橡胶沥青混凝土路面的特点,并对其在工程中的应用技术进行了阐述,指出橡胶沥青混凝土路面具有显著的经济、社会、环境效益,应用前景广阔。%This paper analyzed and compared the cost performance of traditional pavement and rubber concrete pavement, introduced the charac-teristics of rubber asphalt concrete pavement, and elaborated its application technology in engineering, pointed out that the rubber asphalt con-crete pavement had significant economic, social, environmental benefits, had wide application prospect.

  3. 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%.

  4. 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

  5. 炎热多雨地区AC-10型沥青混凝土配合比设计%The AC-10 asphalt concrete mix design technology on the hot and rainy areas

    Institute of Scientific and Technical Information of China (English)

    林彩明

    2012-01-01

    This paper introduces bituminous concrete material selection,mineral aggregate mix proportion design calculations,determine the best asphalt aggregate ratio,test,asphalt concrete production and mix design and verify.The AC-10 asphalt concrete mix proportion technology described on the hot and rainy areas.Provide a reference for the design about expressway asphalt concrete mix.%文章介绍了沥青混凝土配合比的材料选择、矿料配合比设计计算、最佳油石比的确定、试验检验、生产配合比设计及验证,阐述了炎热多雨地区AC-10型沥青混凝土配合比的有关技术,为高速公路沥青混凝土配合比设计提供参考。

  6. Evaluation and verification of two systems for mechanistic structural design of asphalt concrete pavements in Nebraska

    Science.gov (United States)

    Sneddon, R. V.

    1982-07-01

    The VESY-3-A mechanistic design system for asphalt pavements was field verified for three pavement sections at two test sites in Nebraska. PSI predictions from VESYS were in good agreement with field measurements for a 20 year old 3 layer pavement located near Elmwood, Nebraska. Field measured PSI values for an 8 in. full depth pavement also agreed with VESYS predictions for the study period. Rut depth estimates from the model were small and were in general agreement with field measurements. Cracking estimates were poor and tended to underestimate the time required to develop observable fatigue cracking in the field. Asphalt, base course and subgrade materials were tested in a 4.0 in. diameter modified triaxial cell. Test procedures used dynamic conditioning and rest periods to simulate service conditions.

  7. 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。

  8. 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. PMID:20855160

  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. 超载作用下沥青混凝土路面的受力特性分析%Stress Analysis of Asphalt Concrete Pavement Under Overload

    Institute of Scientific and Technical Information of China (English)

    崔学民; 陈德华

    2012-01-01

    Based on the breakage of asphalt concrete pavement of Foshan-Kaiping Expressway, elastic layered theory is used to analyze the stress and deformation of the overloaded asphalt concrete pavement, the effects of overloaded vehicles on stress characteristics and fatigue lifetimes are discussed theoretically.%根据佛开高速公路沥青混凝土路面破损情况,应用弹性层状体系理论分析沥青混凝土路面在超载作用下的应力和变形,从理论上探讨超载车辆对路面的受力特性和疲劳寿命产生的影响.

  12. 浅谈高速沥青混凝土路面施工接缝处理%Discuss the Joint Treatment of Highway Asphalt Concrete Pavement Construction

    Institute of Scientific and Technical Information of China (English)

    樊琳琳

    2014-01-01

    针对高速沥青混凝土路面施工接缝处理,本文主要探讨了路面施工接缝处理和施工接缝碾压工艺等技术。为了提高高速沥青混凝土路面实施接缝处理技术,需要提出有效的合理的措施。%In view of the joint treatment of highway asphalt concrete pavement construction, this article mainly discusses the technologies of pavement construction joint treatment and construction joint compaction craft. In order to improve the i-mplementation of joint treatment technology in highway asph-alt concrete pavement, people need put forward effective and reasonable measures.

  13. AC-16型沥青混凝土配合比设计试验分析%Analysis on mix ratio design test of AC-16 asphalt concrete

    Institute of Scientific and Technical Information of China (English)

    刘长松

    2015-01-01

    以公路沥青混凝土路面工程为例,从目标配合比设计、生产配合比验证方面详细介绍了AC-16型沥青混凝土配合比的相关技术,通过试验分析,确定了最佳油石比,为公路沥青混凝土配合比设计试验提供参考。%Taking the highway asphalt concrete pavement engineering as an example,from the target mix ratio design,production mix ratio test aspects introduced in detail related technology of AC-16 asphalt concrete mix ratio,through the test analysis,determined the optimum asphalt ag-gregate ratio,provided reference for asphalt concrete mix ratio design.

  14. Petroleum contaminated soil in Oman: evaluation of bioremediation treatment and potential for reuse in hot asphalt mix concrete.

    Science.gov (United States)

    Jamrah, Ahmad; Al-Futaisi, Ahmed; Hassan, Hossam; Al-Oraimi, Salem

    2007-01-01

    This paper presents a study that aims at evaluating the leaching characteristics of petroleum contaminated soils as well as their application in hot mix asphalt concrete. Soil samples are environmentally characterized in terms of their total heavy metals and hydrocarbon compounds and leachability. The total petroleum hydrocarbon (TPH) present in the PCS before and after treatment was determined to be 6.8% and 5.3% by dry weight, indicating a reduction of 1% in the TPH of PCS due to the current treatment employed. Results of the total heavy metal analysis on soils indicate that the concentrations of heavy metals are lower when extraction of the soil samples is carried out using hexane in comparison to TCE. The results show that the clean soils present in the vicinity of contaminated sites contain heavy metals in the following decreasing order: nickel (Ni), followed by chromium (Cr), zinc (Zn), copper (Cu), lead (Pb), and vanadium (V). The current treatment practice employed for remediation of the contaminated soil reduces the concentrations of nickel and chromium, but increases the concentrations of all remaining heavy metals. PMID:16957858

  15. 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.

  16. 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. PMID:24316751

  17. 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. PMID:14522190

  18. 橡胶沥青混凝土在高速公路中的应用研究%Application Study of Rubber Modified Asphalt Concrete in Highway

    Institute of Scientific and Technical Information of China (English)

    但瑞强

    2015-01-01

    依托长益高速“白+黑”改造工程,采用马歇尔法对橡胶沥青混合料(ARHM )进行配合比设计,分析混合料的水稳定性、高温稳定性,并对路面指标进行检测、评价。结果表明,橡胶沥青混凝土可用于交通量较大及重载车辆较多的道路,其水稳定性较好,能很好地应用于高速公路中。%Based on Chang‐Yi Expressway “white+black”project ,using Marshall design asphalt mixture of ARHM rubber mixture ratio ,analyzed the mixture high temperature stability ,water resistance ,and pavement indicators are tested and evaluated .Results showed that rubber asphalt concrete can be used to large transportation and heavy vehicles road ,AR‐AC‐13 mixtures are good water stability ,high temperature stability and application of rubber asphalt concrete in Expressway good condition .

  19. 国内外轻集料沥青混凝土研究现状%Research Status of Lightweight Aggregate Asphalt Concrete

    Institute of Scientific and Technical Information of China (English)

    江陈龙; 钱振东; 贾彦卿

    2012-01-01

    轻集料沥青混合料具有密度低、模量高,及优越的抗车辙性、水稳性和抗滑性等特性,但在实际铺面工程的应用仍处于起步阶段,其工程应用价值没有受到应有的重视.对轻集料沥青混凝土的研究现状进行了分析评价,介绍了国内外结构用轻集料技术要求及有关沥青混凝土用轻集料规范及研究现状,为路面、桥面铺面工程研究人员提供参考.%Asphalt mixture incorporating lightweight aggregate is a low density and high modulus paving mixture, of which rutting resistance, moisture susceptibility and skid resistance were better. However it wasnt attached importance to on pavement engineering. The research on the lightweight aggregate asphalt mixture at home and abroad was presented, and the specifications of lightweight aggregate for structure concrete and asphalt concrete pavement were also done. This paper can present some useful reference to paving engineering and researchers.

  20. 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.

  1. 谈橡胶沥青混凝土路面的施工%On construction of rubber asphalt concrete pavement

    Institute of Scientific and Technical Information of China (English)

    李义

    2012-01-01

    Combining the working experience,the paper introduces the construction technique of the rubber asphalt concrete pavement by taking some projects as the example,and illustrates the operation points for some key procedure,including the mixing of the rubber asphalt,the transportation,the paving,and the roller compaction,so as to direct the practice.%结合自身工作经验,以具体工程为例,介绍了橡胶沥青混凝土路面施工技术,分别阐述了橡胶沥青的搅拌、运输、摊铺、碾压等关键工序的操作要点,以期指导实践。

  2. Analysis of Factors Influencing the Asphalt Concrete Pavement Compactness%沥青混凝土路面压实度的影响因素分析

    Institute of Scientific and Technical Information of China (English)

    李彩妹

    2013-01-01

    Compactness is an important step in the construc-tion of asphalt concrete pavement compaction, it can not only ensure the pavement, improve pavement compaction smoot-hness, is also very ef ective for the lower porosity, and can effectively improve the pavement friction, has significant eff-ect on resistance against stress and crack resistance, so stud-ying on the science compaction of asphalt concrete pavement, analyzing the factors affecting the compaction degree of the concrete pavement, control ing these factors, can ef ectively improve the quality of pavement.%沥青混凝土路面施工重要的一个步骤是压实,它不但能确保路面的密实、提升路面的平整度,对降低空隙率也是非常有效果的。而且能有效提升路面摩擦力,对抵抗自然侵害力以及抗裂能力有显著的作用。所以只有研究科学的沥青混凝土路面压实,分析影响混凝土路面压实度的因素,控制好这些因素,才能有效地提高路面的质量。

  3. 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.

  4. 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.

  5. The Construction Technology of Asphalt Concrete Pavement Joints%浅议沥青混凝土路面接缝施工技术

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    Along with the pavement construction technology continues to improve, asphalt concrete pavement has become the current preferred highway bridge pavement. And the pave-ment joint is an important link in the construction of asphalt pavement, and its construction quality directly affects the app-earance and performance of pavement. This paper briefly desc-rybes and analyzes the joint construction technique in asphalt pavement construction.%  随着路面施工技术的不断提高,沥青混凝土路面已成为当前公路道桥工程路面的首选。而路面接缝是沥青路面施工中的重要环节,其施工质量的好坏直接影响着路面的外观及其工作性能。本文针对沥青路面施工中的接缝施工技术方法进行了简要阐述和分析。

  6. Construction Technique of Cement Pervious Concrete with Asphalt Pacver%场地水泥透水混凝土摊铺成型施工技术

    Institute of Scientific and Technical Information of China (English)

    郑莲琼; 周继忠; 蔡雪峰; 林奇; 聂小龙

    2012-01-01

    Technical performance of cement pervious concrete which has a good ecological effect are introduced,detailed descriptions on construction technique of the cement pervious concrete using asphalt paver,construction process,construction key-points are summarized.It can raise working efficiency,reduce cost and improving engineering quality.%水泥透水混凝土场地具有良好的生态效应。本文介绍了水泥透水混凝土的技术性能和工艺原理,重点描述水泥透水混凝土摊铺法成型施工技术。该技术工艺简单、工效高,降低了工程成本,提高了水泥透水性混凝土场地质量。

  7. 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.

  8. 浅谈ARAC-20橡胶沥青混凝土配合比设计%Brief Discussion on Mix Ratio Design of ARAC-20 Rubber Asphalt Concrete

    Institute of Scientific and Technical Information of China (English)

    宫丽辉

    2012-01-01

    Combined with the characteristics of rubber asphalt concrete,attentions and control points during mix ratio design process are discussed.%结合橡胶沥青混凝土的特点,论述在配合比设计过程中的注意事项及控制要点。

  9. Research on Mechanical Experiment for Adding Different Fine Aggregate in Roller Compacted Asphalt Concrete%掺不同细骨料的碾压式沥青混凝土的力学试验研究

    Institute of Scientific and Technical Information of China (English)

    慈军; 李双喜; 努尔开力·依孜特罗甫

    2012-01-01

    The roller compacted asphalt concrete is the material widely used in asphalt concrete core wall.In the mix design,the single-doped artificial sand method is used too much,but its cost is higher.Here,by using the method for mixing the artificial sand and natural sand,the mechanical properties of the asphalt concrete are tested.The results show that the mechanical properties of the asphalt concrete from sand-mixing test could not only meet the requirments of the mix design,but also reduce the cost of asphalt concrete to a certain extent.%碾压式沥青混凝土是目前在沥青混凝土心墙工程中广泛使用的材料,在配合比设计中单掺人工砂的方法应用较多但成本较高。运用混掺人工砂和天然砂配合比的方法,对沥青混凝土的各项力学性能进行试验。研究结果表明:采用人工砂和天然砂混掺的碾压式沥青混凝土的配合比的各项性能均满足配合比设计的要求,同时在一定程度上降低了沥青混凝土的成本。

  10. 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 ...

  11. Experiment Research on Fatigue Property of Double-layer Asphalt Concrete Structure%双层式沥青路面结构极限强度的试验研究

    Institute of Scientific and Technical Information of China (English)

    吴金荣; 马芹永; 董晓红

    2012-01-01

    On the comprehensive action of. wheel load and natural factors, fatigue cracks are obvious on asphalt pavement. In order to improve fatigue life and using character of asphalt pavement, polyester fiber is mixed into asphalt concrete because its high strength, durable and light-weight. So based on double-layer asphalt concrete structure, its ultimate strength is researched on condition of various temperatures, fiber contents and asphalt-aggregate ratios. Change law of its ultimate strength is researched under different test conditions and its main influence factors are also obtained. This will provide a theoretical basis for further spread and application of asphalt pavement.%在车轮荷载和各种自然因素的综合作用下,沥青路面易产生疲劳开裂.为了提高沥青路面的疲劳寿命,将高强、耐久、轻质的聚酯纤维掺加到沥青混凝土中,以改善沥青路面的使用品质.因此,以双层式沥青路面结构为研究对象,研究双层式沥青路面结构在不同温度、不同纤维掺量和不同油石比条件下的极限强度,即在不同试验条件下的极限强度变化规律,根据试验结果得到影响双层式沥青路面结构极限强度的主要因素,为沥青路面的进一步推广应用提供理论依据.

  12. 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.

  13. 沥青混凝土道面反射裂缝的防治与预控%On prevention and pre-control of reflection cracks of asphalt concrete pavement

    Institute of Scientific and Technical Information of China (English)

    江红义

    2012-01-01

    Combining with the work practice, the paper analyzes the formation mechanism and reasons for the reflection cracks on the asphalt concrete pavement, points out the pre-control measures and treatment methods for the reflection cracks, and proves by the engineering example that the application of the prevention technique can reduce the reflection cracks and enhance the stability of the asphalt concrete pavement.%结合工作实践,分析了沥青混凝土道面反射裂缝的产生机理及产生原因,提出了反射裂缝的预控措施和治理方法,通过工程实例证明该防治技术的应用减少了反射裂缝,增强了沥青混凝土面层的稳定性。

  14. 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。

  15. The application of orthogonal experimental design in cast asphalt concrete construction mix design%沥青混凝土配合比设计的正交法应用

    Institute of Scientific and Technical Information of China (English)

    慈平

    2012-01-01

    The method of orthogonal design can be used in asphalt concrete mix design. The results show that the orthogonal experimental design can be achieved with the number of nine test groups to i-dentify indicators to meet the design requirements when the cast asphalt concrete mix design is carried out and the significant influence factors and the level of this test can be found by analysis of variance and range analysis%在进行沥青混凝土配合比设计时,可采取正交设计的方法.结果表明,正交法以九个试验组即可找出满足设计要求的参数指标,并通过方差分析和极差分析可以找出显著的影响因素以及验证本次试验的水平.

  16. Use of scrap rubber in asphalt pavement surfaces

    Science.gov (United States)

    Eaton, Robert A.; Roberts, Richard J.; Blackburn, Robert R.

    1991-12-01

    Scrap tire rubber was mixed into an asphalt concrete wearing course to study the effect of ice disbonding from the pavement surface under traffic. Rubber contents of 0, 3, 6, and 12 percent by weight were studied. Initial laboratory ice disbonding test results led to the development of a new paving material, Chunk Rubber Asphalt Concrete (CRAC), that uses larger pieces of rubber in a much denser asphalt concrete mix. Strength values doubled and ice disbonding performance was enhanced.

  17. 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.

  18. 土石坝沥青混凝土心墙水力劈裂研究%Study on hydraulic fracturing of asphalt concrete core in earth-rock dam

    Institute of Scientific and Technical Information of China (English)

    朱晟; 魏匡民; 饶锡保

    2013-01-01

    Using the operation data of the Finstertal dam and indoor triaxial test results, this paper demonstrates the conditions required to hydraulically fracture an asphalt concrete core under normal reservoir storage, such as dilatancy of asphalt concrete at low confining pressure, and dependence of hydraulic conductivity on porosity. A hydraulic fracturing test of asphalt concrete was carried out and its conditions were simulated numerically. The results reveal that the tiny tensile cracks of test specimens are the inducing factors of hydraulic fracturing. This is significant to the construction of high rock-fill dam with an asphalt concrete core.%结合Finstertal坝的运行资料和室内三轴试验结果,分析了沥青混凝土心墙在蓄水运行过程中存在产生水力劈裂的前提条件,主要包括:沥青混凝土的剪胀性以及渗透系数对孔隙率、骨料级配的依赖性;对沥青混凝土进行了室内水力劈裂试验,并对试验资料进行数值计算的结果表明,试件在受拉时形成的局部微小裂缝的诱导下发生了水力劈裂;结论对高沥青混凝土心墙堆石坝建设具有一定的指导意义.

  19. 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.

  20. ASEISMIC DESIGN OF RESERVOIR FACED WHOLLY WITH ASPHALT CONCRETE%全库铺设沥青混凝土面板水库的抗震设计

    Institute of Scientific and Technical Information of China (English)

    方火浪; 田代幸英; 大内周; 森二郎

    2006-01-01

    介绍在建中日本最大规模的全库铺设沥青混凝土面板水库的抗震设计.基于水库所处的地形、地质及堤体填筑条件,首先对水库整体进行三维有限元动力分析,从总体上掌握水库的地震反应特性;然后对变形较大的断面进行详细的二维动力分析,获得面板的最大动应变.同时,通过大量室内试验,确定满足施工要求的沥青混凝土配合比及其物理力学特性.根据面板的材料特性及其构造特点,提出二级抗震设防的极限状态设计法,并对该水库面板的抗震性能进行校核.%The aseismic design of the reservoir faced wholly with asphalt concrete under construction is addressed, which is the largest one in Japan for this type of reservoir. Due to the complex geomorphologic features and geological structures of the site as well as the complicated construction processes of embankments, general response characteristics of the entire reservoir were firstly investigated by 3D dynamic analyses, and then the maximum strains of the asphalt concrete facing for typical cross-sections of the reservoir with potentially great deformation were determined by detailed 2D dynamic analyses. The results show as follows: (1) both acceleration and strain are with a similar distribution character independent on the direction of the seismic excitation, concentrating in the high banking areas of the main dam, the left-side bank, and from the subsidiary dam to the right-side bank; (2) maximum values of acceleration and strain occur in the main dam although they slightly vary with the excitation direction of the seismic motion; (3) a 2D analytical result is slightly greater than that of a 3D analytical result; and (4) maximum strains of the facing for Levels 1 and 2 seismic waves considering the regional factors of this reservoir site are 0.019% and 0.030%, respectively. At the same time, a series of material tests of asphalt concrete mixtures, including mix design and

  1. 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.

  2. 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。

  3. On the Cold In-place Recycling of Asphalt Concrete Pavement%浅谈沥青混凝土路面现场冷再生技术

    Institute of Scientific and Technical Information of China (English)

    方建明

    2009-01-01

    In the recovery work of Highway Tongeheng-Zhongyang that was damaged after heavy snow, the technique of cold in-place recycling of asphalt concrete pavement to make the new base was applied. Practice indicates that the quality of the new base meet all technical requirement. The article discusses this technique in terms of censtructinn preparation, construction process and test after coastruetinn.%文章介绍桐城至枞阳段雪灾后恢复项目养护工程中冷再生沥青混凝土基层施工,主要从沥青路面现场冷再生施工准备、施工程序、施工后检测的情况,讨论了沥青路面现场冷再生施工技术,实践证明,其冷再生沥青混凝土基层施工质量达到新建基层的各项技术标准.

  4. 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。

  5. Laboratory mix design of asphalt mixture containing reclaimed material

    OpenAIRE

    Davide Lo Presti; Rawid Khan; Norhidayah Abdul Hassan; Gordon Airey; Andrew Collop

    2014-01-01

    This paper presents a study on the production of asphalt test specimens in the laboratory containing reclaimed asphalt. The mixtures considered were stone mastic asphalt concrete mixtures containing up to 30% of reclaimed asphalt. Specimens were compacted to the reference density obtained from the Marshall mix design. Gyration compaction method was used for preparing specimens for the experimental programme, while coring and cutting methods and X-ray computed tomography (CT) were used to inve...

  6. 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).

  7. ALGORITHM OF CHOOSING ASPHALT MIXING PLANTS

    OpenAIRE

    Zhukov, P.; Kravchuk, Y.; Zhukov, D.

    2010-01-01

    The development of transport infrastructure, which must conform to European standards and in its turn requires the development of road economy, is one of the ways out of the crisis. The development of road economy requires either construction of asphalt-concrete mixture plants or their modernization, or reconstruction of existing plants. Any reconstruction or modernization and, moreover, construction of new asphalt-concrete plants requires the optimization of choosing the most efficient aspha...

  8. 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。

  9. 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.

  10. The first engineered self-healing asphalt road: How is it performing?

    OpenAIRE

    Liu, Q.; Schlangen, H.E.J.G.; Van Bochove, G.

    2013-01-01

    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 surface layer, is the main damage mechanism of porous asphalt surface wearing courses. In this research, an induction healing approach (namely, activating the healing process of asphalt concrete through ...

  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. Comparative Durability Analysis of Asphalt Concrete Pavement Reinforced with Two Geosynthetics%两种土工合成材料加筋沥青混凝土路面耐久性对比分析

    Institute of Scientific and Technical Information of China (English)

    何勇海

    2012-01-01

    土工合成材料加筋沥青混凝土路面结构可以提高其疲劳寿命、抗反射裂缝和抗高温车辙能力,成为沥青路面路用技术性能改善的一个有效途径.通过室内试验系统研究了无加筋层、中间加铺玻纤土工格栅或聚酯玻纤布加筋沥青混凝土的低温抗裂性、高温稳定性和抗疲劳性能.试验结果表明,聚酯玻纤布加筋结构具有较好的低温抗裂性能,而玻纤格栅加筋结构的高温稳定性较好.%The asphalt concrete pavement structure reinforced with synthetics can improve the fatigue life, reflective crack resistance and high temperature rut resisting ability. This technique has become an effective way for improvements of road performance of the asphalt pavement. The laboratory test of low temperature resistance, the high temperature stability and anti-fatigue performance are done with the ordinary asphalt concrete pavement structure, reinforced with glass fiber geogrid or polyester glass fiber cloth glass. The test results show that polyester glass fiber cloth reinforcing structure has good low temperature crack resistance energy, while glass fiber reinforcement grid structure has good high temperature stability.

  13. 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.

  14. 沥青混凝土路面就地热再生施工工艺探讨%Discussion on Construction Process of Hot In -Place Recycling Technology of Asphalt Concrete Pavement

    Institute of Scientific and Technical Information of China (English)

    徐安花; 房建宏

    2015-01-01

    Hot in-place recycling technology of asphalt concrete pavement ,w hich has broad application prospects ,has significant economic and technical advantages in waste utilization ,resource saving ,ecological environmental protecting ,etc .In this paper ,in order to provide guidance to site construction of hot in -place recycling technology ,the essential points and attentions of the construction process of hot in -place recycling technology of asphalt concrete pavement are analyzed from its technological type ,heating method ,scarifying method ,adding mode of additive and construction process .%沥青混凝土路面就地热再生技术在废料利用、资源节约和生态环境保护等方面具有显著的技术和经济优势,具有广阔的应用前景。本文从沥青混凝土路面就地热再生主要工艺类型、加热方式、翻松方式、再生剂添加方式及施工过程等方面分析了沥青路面就地热再生技术施工工艺方面的要点及注意事项,以期为就地热再生技术的现场施工提供指导。

  15. Research on Hydraulic Fracturing of Asphalt Concrete Core in Rockfill Dams%土石坝沥青混凝土心墙水力劈裂研究

    Institute of Scientific and Technical Information of China (English)

    侯伟建; 朱晟

    2015-01-01

    Considering the state of the asphalt concrete core in rock‐fill dams ,a hydraulic fracturing test as well as a numerical simu‐lation was conducted to study the mechanism and reason of hydraulic fracturing problem .The results show that deformation can lead to relative large porosity of local regions .These regions may fail in the process of fluid‐mechanical interaction and form the initial hy‐draulic fracturing cracks .There is also a high hydraulic gradient in the area around the crack ,which is considered to be a necessary condition for hydraulic fracturing .This paper analyzes in‐situ observation data of Yele Dam's first filling .Observation data show that the uneven relative displacement between the core and transition materials produced a strong reduction of vertical compressive stress even a tensile stress ,which is an important physical condition for hydraulic fracturing .%针对土石坝沥青混凝土心墙的工作特点,采用室内试验以及数值模拟试验结合的手段对沥青混凝土水力劈裂的发生机理、产生原因进行了研究,结果表明,后期变形导致的孔隙率的增大使得沥青混凝土试样局部区域出现较大的渗透性,在颗粒骨架与水压力相互作用过程中此局部区域失效破坏,形成初始的水力劈裂裂缝。同时发现裂缝周边存在很大的水力梯度,这被众多学者认为是发生水力劈裂的必要条件。进而分析了冶勒沥青混凝土心墙坝初次蓄水的原位观测资料,资料表明沥青混凝土心墙与过渡料之间存在着较大的相对不均匀位移,这使得心墙局部区域竖直压力骤减甚至出现拉应力,它是诱导沥青混凝土发生水力劈裂的重要条件。

  16. 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.

  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. Evaluation of asphalt-rubber membrane field performance

    Science.gov (United States)

    Shuler, S.; Gallaway, B. M.; Epps, J. A.

    1982-05-01

    This report presents a record of asphalt-rubber membrane field performance in Texas. An evaluation of performance is presented for forty-five separate projects in thirteen state highway districts. Approximately 850 lane miles of highways are represented by materials constructed as stress absorbing membranes (asphalt-rubber seal coats beneath asphalt concrete overlay). All projects reviewed were constructed between June, 1976 and September, 1981.

  19. 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.

  20. Evaluation of Hydrated Lime Filler in Asphalt Mixtures

    OpenAIRE

    Mohammed Abbas Hasan Al-Jumaily

    2008-01-01

    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 fund...

  1. Study on Axle Load Conversion for Concrete Base of Durable Asphalt Pavement%耐久性沥青路面混凝土基层轴载换算研究

    Institute of Scientific and Technical Information of China (English)

    郑木莲; 陈拴发; 马庆雷

    2012-01-01

    刚性基层耐久性沥青路面作为一种新型的路面结构,现行规范对于上覆沥青层水泥混凝土路面的设计思路对其并不适用,其轴载换算公式由于没有考虑刚性基层沥青路面结构的特点,得出的结果存在较大误差.依据普通混凝土及贫混凝土的疲劳方程,结合耐久性沥青路面混凝土基层在标准轴载和不同轴-轮型荷载作用下回归得出的荷载应力计算公式,按照混凝土基层等效疲劳损伤原则,推求得出单轴-单轮、单轴-双轮组、双轴-双轮组荷载换算为标准轴载的公式.结果表明:得出的轴载换算公式可充分考虑混凝土基层耐久性沥青路面基层厚度、基层模量、地基模量结构设计参数的影响,具有良好的实用性,可为路面结构设计提供依据.%As a new kind pavement structure, the design method of cement concrete pavement with asphalt surface course in the current specification is not suitable to the durable asphalt pavement with rigid base. Since the characteristics of durable pavement with rigid base are not taken into account, there exists large error in the results getting from the axle-load conversion equation. According to the fatigue equations of popular concrete and lean concrete, the load stress calculation equations rigid base in durable asphalt pavement subjecting standard axle load and different axle-wheel load, and the equivalent fatigue damage principle of concrete base, the axle load conversion equations from the load of single-axle and single-wheel, single-axle and two-wheel and two-axle and two-wheel to the standard axle load are derived. The results show that the axle load conversion equations got in the paper can fully consider the influences of the structure design parameters of base depth, base modulus and subgrade modulus etc. Of durable asphalt pavement with concrete pavement, so the equations have good suitability and can provide basis for pavement structure design.

  2. ANSYS在沥青混凝土心墙坝渗流分析中的应用%Application of ANSYS in Seepage Analysis of Asphalt Concrete Core Wall Dam

    Institute of Scientific and Technical Information of China (English)

    寇甲兵; 米艳芳; 杨必娴

    2014-01-01

    针对有限元软件在沥青混凝土心墙坝渗流场分析中的应用进行了研究。沥青混凝土结构以其极佳的防渗性能、良好的自适应变形能力等优势,被越来越多的工程所采用,而渗流稳定一直以来都被认为是影响土石坝安全运行的主要控制因素。结合工程实例,应用有限元软件对沥青混凝土心墙坝的渗流场进行分析,对其渗流稳定情况进行计算。实例应用表明,将ANSYS有限元软件应用于沥青混凝土心墙坝的渗流场分析,能较直观、快速、真实地反映坝体渗流场的实际运行情况,有较强的工程实用价值。%The application of ANSYS in seepage analysis of asphalt concrete core wall dam are stud-ied in this paper.Asphalt concrete structure showed a strong development momentum with the advan-tages of its excellent anti -seepage performance , good ability of adaptive deformation , which has been adopted by more and more engineering , but for a long time , seepage stability has been consid-ered to be the main control factors of influencing safe operation of earth and earth -rock dam.Combi-ning with the engineering example , this paper analyses the seepage of asphalt concrete core wall dam with finite element software , to calculate seepage stability conditions.Project instance analysis indi-cate that the adoption of the finite element software ANSYS method can directly、fast and truly reflect the real operation situations of seepage field , which have strong engineering practical value.

  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. Asphalt cement poisoning

    Science.gov (United States)

    ... petroleum material that hardens when it cools. Asphalt cement poisoning occurs when someone swallows asphalt. If hot ... found in: Road paving materials Roofing materials Tile cements Asphalt may also be used for other purposes.

  5. To Guarantee the Quality of Asphalt Concrete Pavement in Road Construction%谈道路施工中沥青混凝土路面的工程质量保障

    Institute of Scientific and Technical Information of China (English)

    邱龙

    2013-01-01

      The road construction project is an important part of the municipal infrastructure construction, and the road construction quality affects the people's daily life and the urban appearance directly. This article will mainly analyze the problems of the asphalt concrete pavement construction in the road construction, and discuss the way to guarantee the quality of pavement construction.%  道路施工工程是城市基础设施建设的重要组成部分,道路施工质量的好坏直接影响着人们的日常生活以及城市的市容。本文将主要就道路施工中沥青混凝土路面施工存在的问题进行分析,就如何对路面施工质量提供保障进行探讨。

  6. 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

  7. 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.

  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 Optimal Method for Mix Design of Cation Emulsified Asphalt Concrete%阳离子乳化沥青混凝土配合比设计的优选方法研究

    Institute of Scientific and Technical Information of China (English)

    何建新; 郭鹏飞; 刘录录; 杨力行

    2013-01-01

    The optimization of cement content ,emulsion amount and mixing water consumption is carried out by uniformly orthogonal test to obtain the basic mix parameters of cation emulsified asphalt concrete .Through determining the stability and flow value of asphalt concrete specimens ,the influence law of the cement content ,emulsion amount and mixing water consumption on the stability and flow value is studied by using PPR .It is found from the study that the maximum influ-encing factor on the stability and flow value is cement content ,secondly it is emulsion amount ,and the minimum one is mixing water consumption .%  采用均匀正交试验对水泥掺量、乳液用量、拌合用水量三个因素进行优选,得到阳离子乳化沥青混凝土的基础配合比参数。通过测定每组沥青混凝土试件的稳定度和流值,并采用投影寻踪回归分析法(PPR)研究了水泥掺量、乳液用量和拌合用水量对稳定度和流值的影响规律,研究发现,对于稳定度和流值影响最大的因素是水泥掺量,其次是乳液用量的影响,而拌合用水量对稳定度和流值影响较小。

  10. 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...

  11. 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.

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

    OpenAIRE

    Ludfi Djakfar; Hendi Bowoputro; Bangun Prawiro; Nugraha Tarigan

    2015-01-01

    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...

  13. On the Asphalt Mixture Ratio Design

    Institute of Scientific and Technical Information of China (English)

    谢文怡

    2013-01-01

      热拌沥青混合料配合比设计关系到沥青砼路面的路用性能。本文结合高速公路沥青路面建设的实际情况,对如何规范操作,以及设计沥青混合料配合比时注意的问题提出了一些建议。%Hot-mix asphalt mixture design is related to the performance of asphalt concrete pavement. This paper, combining with the actual situation of the highway asphalt pavement construction, made recommendations on how to regulate the operation and the problems need pay attention to in design of asphalt mixture.

  14. GREENPATCH® - Cold Mix Asphalt

    OpenAIRE

    ECT Team, Purdue

    2013-01-01

    GreenPatch® is environmentally friendly cold asphalt that is a direct replacement for traditional cold patch in repairing asphalt pavements. This revolutionary breakthrough in the cold asphalt industry contains no petroleum based softeners such as diesel, toluene, kerosene, and naphthalene found in conventional cold asphalt that pose serious threats to human health and the environment.

  15. 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

    2016-04-01

    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.

  16. 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.

  17. Application Research on Preventing Measures against Reflection Cracks of Asphalt Concrete Surface Covering Old Cement Pavement%旧水泥路面沥青加铺层防反射裂缝措施的应用与分析

    Institute of Scientific and Technical Information of China (English)

    张泽鹏; 王钊

    2014-01-01

    In this paper,the five common prevention measures against reflection crack that produced in asphalt concrete pavement covering an old cement concrete pavement have been introduced,including self-adhesive belt, thermal bonding belt,SAMI stress absorbing layer,geotextile and glass fiber grid. Through indoor fatigue tests and outdoor tests,comparison and analysis on application characteristic of the five prevention measures have been put forward.%针对旧水泥混凝土路面沥青加铺层结构中自粘式压缝带、热粘式压缝带、SAMI 应力吸收层、土工布及玻纤格栅等常用的五种延缓反射裂缝的处理措施,通过对其进行室内疲劳试验分析和室外试验评价,对比分析这五种处理措施的应用特点。

  18. Test Study on Asphalt Concrete Fatigue Performance Under Rich-water Conditions%富水条件下沥青混凝土疲劳性能试验研究

    Institute of Scientific and Technical Information of China (English)

    秦旻; 梁乃兴; 陆兆峰; 曹源文

    2012-01-01

    Stress-controlled mode can reflect mechanical response of thicker pavements, so it is used to carry out indirect tensile fatigue test of commonly used AC-25 asphalt concrete in different test conditions which are designed by anhydrous and rich-water respectively. With the fatigue test results by various stress level, the equations of stress-life fatigue for asphalt concrete were obtained. The water impacts on fatigue performance were analyzed from fatigue life, characteristic parameters of fatigue e-quation and fatigue failure modes. The results indicate that the fatigue life of rich-water asphalt concrete is only about 24~30% of anhydrous concrete in the same stress level, and there is good linear relationship between stress level and fatigue life in double- logarithm coordinates which can be serve as a basis to forecast fatigue life. At the same time, the fatigue failure form of shear and splitting combined effect in rich-water condition fully proved that it is reasonable of using freeze-thaw cycling to simulate severely water damage.%根据厚沥青面层自身的受力特点,采用应力控制模式对高速公路沥青路面下面层常用AC-25沥青混凝土进行无水和富水条件下间接拉伸疲劳试验,得到不同应力水平作用下的疲劳试验结果,回归建立了应力-疲劳方程,并从疲劳寿命、疲劳方程特征参数、疲劳破坏形态等方面分析了水对沥青混凝土疲劳性能的影响.研究结果表明,在相同的应力水平作用下,富水沥青混凝土疲劳寿命仅约为无水沥青混凝土的24%~30%;沥青混凝土的应力水平与疲劳寿命在双对数坐标中呈现较好的线性关系,可为沥青路面疲劳寿命预估提供依据;富水状态下试件疲劳破坏表现为剪切和劈裂联合作用形式,充分证明用冻融循环处理条件模拟沥青混凝土富水状态的合理性.

  19. Micro-scale moisture damage characteristics in epoxy asphalt concrete%环氧沥青混合料细观尺度水损坏特性

    Institute of Scientific and Technical Information of China (English)

    胡靖; 钱振东

    2013-01-01

    The mechanical characteristics of early moisture damage of epoxy asphalt ((EA) is researched based on microscopic technology, and a micro finite element model which contains aggregate, bonding interface and asphalt mortar is established. The cohesive zone model (CZM) is introduced to discrete the interface area between aggregate and asphalt mortar, and the crack initiation, extension and failure process of interface between aggregate and asphalt mortar under moisture diffusion condition is simulated. Meanwhile, the mechanical characteristics of EA when aggregate exfoliate and break due to coupling effect of moisture and load is analyzed. The results show that the moisture saturation has a great effect on the mechanical response of EA and the debonding destroy mainly appears in the peripheral area of coarse or irregular-shaped aggregate. The degree of moisture damage of asphalt mixture is aggravated if the saturation increases, and the rate of debonding failure increases sharply in high saturation. The asphalt mortar around aggregate bears worse mechanical state, and moisture damage occurs in this area easily. The moisture damage of EA is greatly affected by the volume characteristics of aggregate, so the proportion of coarse aggregate in mixture should be controlled.%基于细观尺度技术研究环氧沥青混合料(EA)早期水损破坏的力学特性,建立集料-黏结界面-沥青砂浆平面细观力学有限元模型.引入内聚力模型(CZM)对集料与沥青砂浆界面进行离散,模拟EA在水分渗透过程中集料与沥青砂浆界面裂缝的萌生、扩展直至失效的过程,分析载荷与水分耦合作用下EA出现集料剥离与裂缝的力学特性.研究表明:EA的力学响应受材料含水率的影响很大,剥落主要发生在体积较大且形状不规则的集料周围;材料含水率增加会加剧沥青混合料水损破坏的程度,集料剥离呈快速增大趋势;集料四周薄弱界面区域内的沥青砂浆在受力

  20. 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 .

  1. 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.

  2. 沥青混凝土心墙土石坝水力劈裂计算分析%Calculation and Analysis on Hydraulic Fracturing of Asphalt Concrete Core-wall Earth-rockfill Dam

    Institute of Scientific and Technical Information of China (English)

    代凌辉; 张营营; 吴佳

    2016-01-01

    分析了土石坝水力劈裂原理,针对新疆吐鲁番二塘沟沥青混凝土心墙土石坝,选取河床部位最大断面为典型断面,采用有限元法对其进行水力劈裂计算分析,得出:该土石坝心墙任一高程处的中主应力都小于竖向应力,且中主应力和竖向应力都大于水压力。因此,该坝的心墙不会发生水力劈裂。%This paper analyzes the principle of earth-rockfill dam hydraulic fracturing , selects the biggest section in river area for typical sections and conducts the calculation and analysis of hydraulic fracturing by using the finite element method for Xinjiang turpan ertanggou asphalt concrete core-wall earth-rockfill dam. It comes to the conclusion that the intermediate principal stress of any elevation in core-wall earth-rockfill dam is less than the vertical stress , and the intermediate principal stress and vertical stress is greater than the water pressure. So, the core-wall hydraulic fracturing of the dam is not going to happen.

  3. Performance of asphalt rubber mixtures

    OpenAIRE

    Thives, Liseane Padilha; Trichês, Glicério; Pereira, Paulo A. A.; Pais, Jorge C.

    2010-01-01

    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: terminal blending (produced at industrial plants) and continuous blending (produced in asphalt plants). This study presents a laboratory evaluation of asphalt rubber mixtures produced with d...

  4. 旧水泥混凝土路面加铺水泥-泡沫沥青半柔性混合料的力学响应分析%Analysis of mechanical response of semi-flexible mixture material of cement-foam asphalt overlayed on old concrete pavement

    Institute of Scientific and Technical Information of China (English)

    李秀君; 李梦晨; 武昭融

    2013-01-01

    Aimed at the problem that old concrete pavement overlayed with asphalt surface is prone to reflective cracking,the paper proposed that the old concrete pavement overlayed with the semi-flexible mixture of cement-foam asphalt should significantly reduce the possibility of surface cracking.In order to guide pavement structure design,the paper studied the mechanical performance of the old concrete pavement by using ANSYS finite-element method,and got the conclusion that the method would significantly reduce the tensile stress and maximum shearing stress in asphalt layer and relieve the cracking of the asphalt pavement.In addition,it would reduce the sensitivity of asphalt surface crack width of the old cement board.The thickness of semi-flexible mixture material paved on the old concrete pavement should not less than 8cm.%针对旧水泥路面加铺沥青面层易出现反射裂缝问题,本文提出在旧水泥混凝土路面上铺筑水泥-泡沫沥青半柔性混合料再铺筑沥青面层,可显著降低面层开裂的可能性.为合理指导路面结构设计,论文采用ANSYS有限元软件进行路面结构力学计算,研究水泥-泡沫沥青半柔性混合料对路面结构力学的响应.研究得出旧水泥板上加铺水泥-泡沫沥青半柔性材料,可显著减弱沥青面层层底拉应力及层内最大剪应力,可有效缓解沥青层的反射裂缝的出现,同时还可以显著降低沥青面层对旧水泥板裂缝宽度的敏感性.在旧水泥混凝土板上加铺水泥-泡沫沥青半柔性混合料,其厚度不宜低于8 cm.

  5. Laboratory Mix Design of Asphalt Mixture Containing Reclaimed Material

    Directory of Open Access Journals (Sweden)

    Davide Lo Presti

    2014-01-01

    Full Text Available This paper presents a study on the production of asphalt test specimens in the laboratory containing reclaimed asphalt. The mixtures considered were stone mastic asphalt concrete mixtures containing up to 30% of reclaimed asphalt. Specimens were compacted to the reference density obtained from the Marshall mix design. Gyration compaction method was used for preparing specimens for the experimental programme, while coring and cutting methods and X-ray computed tomography (CT were used to investigate the change in properties within the specimens and to validate the selected methodology. The study concluded that gyratory compaction is suitable to produce homogeneous test specimens also for mixtures containing high amount of reclaimed asphalt. Nevertheless, preliminary trials for each material are mandatory, as well as final coring and trimming of the specimens due to side effects.

  6. Typical Structure of Bridge Deck Asphalt Pavement of Cement Concrete Bridge%水泥混凝土桥沥青铺装典型结构研究

    Institute of Scientific and Technical Information of China (English)

    何德云; 熊欣; 董强

    2011-01-01

    Vehicle's safety and comfort has been directly affected by the quality of bridge deck pavement, and the quality of bridge deck pavement has been directly affected by the composite structure of bridge deck pavement. Through the interlayer cohesive tests with 7 sorts of materials, temperature stability and fatigue bending tests with 3 composite structures, the performance sequence of interlayer cohesive materials and asphalt composite structures have been confirmed. On the basis of the test results, the typical structure of bridge deck pavement has been proposed, which offers references for the design and construction of bridge deck pavement.%桥面铺装的质量直接影响着行车的安全性和舒适性,桥面铺装的结构组合又直接决定了桥面铺装的质量.通过对7种桥面铺装层材料的层间黏结性能试验、3种桥面铺装组合结构的温度稳定性试验和复合小梁弯曲疲劳试验,确定了桥面铺装层间黏结材料和沥青铺装结构的性能排序,在此基础上提出了桥面铺装的典型结构型式,可为桥面铺装设计和施工提供参考.

  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. Mechanical Response Analysis of Asphalt Pavement Structure

    Directory of Open Access Journals (Sweden)

    Yu Zhenqing

    2015-11-01

    Full Text Available Generally, the Chinese designed life of the high- grade asphalt concrete pavement is required 15 years, however, the designed life of the road in surface is often lower than the designed life, and even premature failure. Especially in heavy traffic conditions, the early damage of some high grade-asphalt pavement in China is serious. According to some investigations, we founded the main reason of the long-life asphalt pavement is to determine the function of each structure layer. According to the stress of pavement structure layer, so as to select the structure layer materials. Based on the viewpoint of mechanics, asphalt pavement damage mode is divided into three categories, such as top-down crack, fatigue cracking and rutting. Therefore, this paper uses ANSYS finite element software as calculation tool, the combination of road vehicle load and the primary influence on asphalt pavement structure mechanics response characteristics were analyzed. In this paper, the method of analysis is control variable: that means under different vehicle axle load, only change surface layer modulus and observe the pavement structure mechanical response trends to compare the effect. By using the same method, the response of the pavement base course parameters to the pavement mechanical structure is analyzed.

  9. Effects of conductive fillers on temperature distribution of asphalt pavements

    International Nuclear Information System (INIS)

    The sun provides a cheap and abundant source of clean and renewable energy. Solar cells have been used to capture this energy and generate electricity. A more useful form of the solar cell would be asphalt pavements, which get heated up by solar radiation. Graphite powders are utilized as thermal conductive fillers to make an asphalt collector conductive so as to improve the efficiency of the asphalt collector. Accounting for the important application conditions and evaluating the effects of the heat conductive materials and the solar energy absorbability of the conductive asphalt collector, a finite element model has been developed to predict temperature distributions in the conductive asphalt solar collector. In this study, an experimental validation exercise was conducted using the measured data taken from full-depth asphalt slabs. Validation results showed that the model can satisfactorily predict the temperature distributions in asphalt concrete slabs. The optimal depth is 25-50 mm for placing pipes that serve as the heat exchanger. Meanwhile, the effect of the surroundings on the solar energy potential of the asphalt collector was noticeable.

  10. Effects of conductive fillers on temperature distribution of asphalt pavements

    Science.gov (United States)

    Mingyu, Chen; Shaopeng, Wu; Yuan, Zhang; Hong, Wang

    2010-05-01

    The sun provides a cheap and abundant source of clean and renewable energy. Solar cells have been used to capture this energy and generate electricity. A more useful form of the solar cell would be asphalt pavements, which get heated up by solar radiation. Graphite powders are utilized as thermal conductive fillers to make an asphalt collector conductive so as to improve the efficiency of the asphalt collector. Accounting for the important application conditions and evaluating the effects of the heat conductive materials and the solar energy absorbability of the conductive asphalt collector, a finite element model has been developed to predict temperature distributions in the conductive asphalt solar collector. In this study, an experimental validation exercise was conducted using the measured data taken from full-depth asphalt slabs. Validation results showed that the model can satisfactorily predict the temperature distributions in asphalt concrete slabs. The optimal depth is 25-50 mm for placing pipes that serve as the heat exchanger. Meanwhile, the effect of the surroundings on the solar energy potential of the asphalt collector was noticeable.

  11. 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. PMID:27115043

  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. 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…

  15. Design of mix proportion of roller-compacted asphalt concrete core wall in Pangduo Hydraulic Complex%旁多大坝碾压式沥青混凝土心墙配合比设计

    Institute of Scientific and Technical Information of China (English)

    向尚君; 邱炽兴; 赵兴安

    2013-01-01

    西藏旁多水利枢纽大坝采用碾压式沥青混凝土心墙防渗,这是沥青混凝土防渗心墙第一次在高海拔地区的应用。心墙不但要适应深覆盖层、高地震烈度引起的大变形,同时还要考虑高海拔地区低温、强辐射和夏季多雨的气候对心墙施工质量的影响。经现场原材料选择和室内试验,初步确定沥青混凝土配合比后,再经施工模拟试验调整和生产性试验验证,最终确定了适应旁多水利枢纽大坝碾压式沥青混凝土心墙的施工配合比。经过两年的施工验证和现场取芯试验,心墙的各项性能指标均符合设计要求。详细介绍了配合比的设计过程,可供同类工程参考。%The roller-compacted asphalt concrete core wall is adopted as anti-seepage measures of Pangduo Hydraulic Com-plex in Tibet, which is firstly applied in high altitude areas. The core wall should adapt to large deformation caused by deep over-burden and high seismic intensity and the influences of low temperature, strong radiation in high altitude area and the rainy cli-mate in summer acting on construction quality should be considered. The concrete mix proportion of the core wall is firstly deter-mined by in-site selection of raw material and the laboratory test. The suitable mix proportion was finally determined by adjust-ment of the construction simulation test and the verification of productive test. Every performance index of the wall meets the de-sign requirements with a two-year constructional proof and boring sample test. Moreover, the design process of mix proportion is also illustrated in detail.

  16. 基于离散单元法的环氧沥青混凝土虚拟断裂试验研究%Experimental study on virtual fracture of epoxy asphalt concrete based on discrete element method

    Institute of Scientific and Technical Information of China (English)

    江祥林; 钱振东; 宋鑫

    2014-01-01

    In order to clarify the fracture mechanical behaviors of epoxy asphalt concrete (EAC),a single-notched beam two-dimensional model was established by the discrete element method based on digital image processing technology.The virtual bending fracture tests of EAC were performed to stud-y the mechanical response in the fracture process of EAC under meso-scale.The fracture mechanism and cracks propagation paths were analyzed and compared with the laboratory test results.The results show that the discrete element method can be used to exhibit the fracture characteristics of EAC ex-cellently.The mechanical responses of the virtual tests obtained by numerical simulation are coinci-dent with the theoretical results.The material strength parameters acquired by the virtual test are close to those of the indoor tests,with an error of 0.25%.However,the stiffness modulus obtained by the virtual test is 16.56%lower than the test results due to the large deflection.The damage tends to occur in the interface with inferior adhesive performance between the aggregate and asphalt mastic during the cracks propagation.The comparison between the virtual test results and the experimental results verify the availability of the discrete element model and the relevant material parameters.%为明晰环氧沥青混凝土的断裂力学行为特征,基于数字图像处理技术,采用离散元方法建立了切口小梁二维模型,开展了环氧沥青混凝土的虚拟弯曲断裂试验.从细观角度分析了环氧沥青混凝土断裂过程中的力学响应,探讨了其断裂机理及裂纹扩展路径,并与室内试验结果进行了对比.结果表明,采用离散元方法可较好地反映环氧沥青混凝土的断裂力学特性,数值模拟过程中虚拟试件的力学响应与理论结果相符.虚拟试验获取的材料强度参数与室内试验的测试结果接近,误差仅为0.25%,但前者所得的劲度模量因破

  17. 环氧沥青混凝土裂纹发展的三维可视化离散元模拟%Three-dimensional Visualization Discrete Element Modeling of the Crack Development of Epoxy Asphalt Concrete

    Institute of Scientific and Technical Information of China (English)

    王江洋; 钱振东; Wang Lin-bing

    2014-01-01

    为了在三维尺度下描述环氧沥青混凝土的裂纹发展行为,运用离散元程序PFC3D内置“Fish”语言,重构了环氧沥青混凝土非均质(集料、砂浆和空隙)多层次(矿料级配)结构三维虚拟试件,对虚拟试件微观组成成分之间的接触赋予了相应的微观接触模型,采用离散元方法实施了单边切口小梁虚拟三点弯曲试验,追踪并演示了微观裂纹的衍生发展全过程,并与室内数字摄像法捕捉的试件表面裂纹发展进行对比。研究结果表明:虚拟试验得到的宏观断裂力学响应与室内试验结果的吻合度较好,且虚拟试验结果的稳定性更优;三维离散元方法可以较好地模拟环氧沥青混凝土弯曲断裂过程中裂纹起裂与扩展行为,弥补了二维方法部分缺陷;基于离散元程序的追踪裂纹三维发展的模拟方法,可以作为研究沥青混凝土材料断裂特征的辅助手段。%In order to describe the crack development of epoxy asphalt concrete (EAC)from the three-dimensional (3D)scale perspective,a 3D virtual specimen of EAC with the heterogeneous (coarse aggre-gates,asphalt mastic and air voids)and multilayer (aggregate gradation)morphological features was first reconstructed by using the Fish language provided in the discrete element software PFC3D.Secondly,the corresponding micromechanical models describing the interaction of micro-scale components of the virtual specimen were assigned.Finally,a single-edge notched beam virtual three-point bending test was imple-mented by using the discrete element method (DEM).The progressive development of microcrack traj ecto-ries was tracked and visualized,and the simulation results were compared with the surface crack develop-ment of specimens captured in a digital camera method.The results have indicated that the macro fracture responses of virtual test show generally good agreement with the experiment results,and the virtual test presents

  18. 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.

  19. 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…

  20. 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.

  1. Effects of circulating fluidized bed combustion (CFBC) fly ashes as filler on the performances of asphalt

    Energy Technology Data Exchange (ETDEWEB)

    Qin Li; Hui Xu; Xiaoru Fu; Chen Chen; Jianping Zhai [Nanjing University, Nanjing (China). State Key Laboratory of Pollution Control and Resource Reuse

    2009-03-15

    This work investigated the potential of utilizing circulating fluidized bed combustion (CFBC) fly ashes (CFAs) as alternative filler, substituting mineral powders (MPs) that are widely used in asphalt concrete. Physico-chemical characteristics of the CFAs and MPs, as well as effects of different mix designs of CFAs and asphalt on asphalt performances were examined, including moisture susceptibility, viscosity, ductility, softening point, penetration, and antiaging performances. The results of the study show that generally the CFAs have greater effects than the MPs on improving the performances of asphalt, and that the specific surface area (SSA), free CaO (f-CaO), morphology, and mineralogical phases of the CFAs are more favorable than those of the MPs respectively, while the alkaline values, hydrophilic coefficients, particle size distributions (PSDs), and water contents of the two fillers are similar. It is suggested that CFAs may be more suitable than MPs for the use as asphalt concrete filler.

  2. 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

  3. Nuclear asphalt content gauge study. Research report (Final)

    International Nuclear Information System (INIS)

    This research ascertains if the Troxler Model 3241 Gauge could accurately determine the asphalt content of bituminous-concrete mixtures by nuclear means. The study was divided into three phases. Phase I was conducted in the Central Laboratory where a series of controlled tests were performed for variables that may effect the gauge's asphalt-content determinations. Phase II evolved into a cooperative study between the Maryland State Highway Administration (SHA) and several bituminous concrete producers. Phase III was to report the findings of the study and make a recommendation on the overall practical application of the gauge. The results indicate that the gauge can accurately determine asphalt contents on normal surface and base bituminous mixtures

  4. Investigation of the radiation shielding capacity of asphalt and sand for fast neutron sources

    International Nuclear Information System (INIS)

    The internal wall of the cavity of experimental assemblies, involved with high energy fusion neutrons, can be covered by an asphalt-sand layer for radiation protection purposes. The calculations have demonstrated that asphalt has a radiation protection capability superior to that of concrete, on equivalent weight basis. For an experimental cavity using a 10 (12) neutrons/sec neutron generator, the best structure has been found to be a 10% asphalt-90% red sand homogeneous mixture, against neutron + gamma energies, with a protection capability of more than 200% compared to the same thickness of a concrete structure. This work has proved that the local and cheap asphalt and sand can replace the relatively expensive concrete in constructing biological radiation shielding of experimental assemblies on fusion neutronics. 15 refs

  5. Research on Performance of High-elastic and High-viscous Rubber Asphalt Concrete%橡胶高粘高弹沥青混凝土性能研究

    Institute of Scientific and Technical Information of China (English)

    王建章; 李红; 罗莉婷

    2016-01-01

    Based on the preferred material,high-elastic and high-viscous rubber modified asphalt is prepared,its material properties are tested and the performance characteristics are studied in the pa-per.OGFC mixture is prepared with high-elastic and high-viscous asphalt,high-viscous asphalt,TPS modified asphalt respectively,and their road performance are compared.The results showed that:high-elastic and high-viscous rubber modified asphalt mixture has excellent water stability,high tem-perature stability.%在优选材料的基础上,制备了橡胶高粘高弹改性沥青,测试了其材料性能并研究了其性能特点。文中对采用高粘高弹沥青、高粘沥青、TPS 改性沥青配制的 OGFC 沥青混合料其路用性能进行了对比研究。研究结果表明,橡胶高粘高弹改性沥青混合料具有优异的水稳定性能和高温稳定性能。

  6. 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...

  7. Application of Rubber Asphalt Concrete Pavement in Port Area Roads%橡胶沥青混凝土路面在港区道路中的应用

    Institute of Scientific and Technical Information of China (English)

    莫晓华

    2015-01-01

    In allusion to heavy load traffic feature of port roads,this paper carries out indoor uniaxial compression test,wheel rutting test and bending test of small beams for rubber asphalt mixture.The results show that the elastic modulus and high -temperature property of rubber asphalt mixture are equivalent to SBS modified asphalt mixture,but fatigue performance is the best and above 1 time higher than matrix asphalt mixture.The paper applies rubber asphalt mixture to test sections,and the results show that the surface water seepage coefficient,compactness of mixture,structure depth and surface resistant coefficient of rubber asphalt pavement can satisfy the basic requirements of the specifications.On the basis of test, the paper proposes pavement structural form 4cm rubber asphalt AC -13 +6cm matrix asphalt AC -20 applicable to port roads.%针对港区道路的重载交通特性,进行橡胶沥青混合料室内单轴压缩试验、车辙试验及小梁弯曲试验。结果表明:橡胶沥青混合料的回弹模量、高温性能与 SBS 改性沥青混合料相当,但其疲劳性能最好,比基质沥青混合料高1倍多。将橡胶沥青混合料用于试验路段,结果表明:橡胶沥青路面的路表渗水系数、混合料压实度、构造深度以及表面抗滑系数都能够满足规范基本要求。基于试验,提出港区道路适用的路面结构形式为4 cm 橡胶沥青 AC -13+6 cm 基质沥青 AC -20。

  8. Asphalt chemical fractionation

    International Nuclear Information System (INIS)

    Asphalt fractionation were carried out in the Esmeraldas Oil Refinery using n-pentane, SiO2 and different mixture of benzene- methane. The fractions obtained were analyzed by Fourier's Transformed Infrared Spectrophotometry (FTIR)

  9. 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.

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

    Science.gov (United States)

    Dubravský, Marián; Mandula, Ján

    2015-11-01

    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.

  11. A review of asphalt and asphalt mixture aging

    OpenAIRE

    Wilmar Darío Fernández-Gómez; Hugo Alexander Rondón Quintana; Fredy Reyes-Lizcano

    2012-01-01

    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-ter...

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

    OpenAIRE

    Dubravský Marián; Mandula Ján

    2015-01-01

    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 decl...

  13. 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.

  14. 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

  15. 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

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

    OpenAIRE

    Murat Karacasu; Volkan Okur; Arzu Er

    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 stres...

  17. 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.

  18. 旧水泥混凝土路面沥青罩面层间处治方案对比研究%Study on the Interlayer Treatment Methods of Old Cement Concrete Pavement and Asphalt Overlay

    Institute of Scientific and Technical Information of China (English)

    樊永华

    2015-01-01

    基于拉拔试验、APA 试验以及扭剪疲劳试验研究了橡胶沥青应力吸收层、橡胶粉改性 AC —5沥青混合料、玻璃格栅+纤维改性沥青混合料3种应力吸收层的层间粘结特性、抗反射裂缝能力和抗疲劳耐久性,试验结果表明,采用砂粒式 AC —5橡胶粉改性沥青混合料方案的层间粘结强度最大,且其在水-温耦合作用下抗反射裂缝效果最好,而玻璃格栅+纤维改性沥青混合料抗扭曲疲劳性能最好,总结了一套应力吸收层方案选择及性能评价的试验方法,为“白改黑”工程应力吸收层结构选择提供理论借鉴。%Based on the pull-out tests,APA and torsional shear fatigue tests to study the layer in-terlayer adhesion properties,anti-reflective and anti-fatigue crack durability of stress-absorbing layer of rubber asphalt,rubber modified AC-5 asphalt,glass fiber grille + modified asphalt mixture of three kinds of stress absorbing.results show that:using inter-layer sand type AC-5 rubber modified asphalt bond strength is maximum,and in the water-temperature coupling the action of reflection crack resistance effect is best,And the glass grill +fiber modified asphalt mixture fatigue strength for the best distortion, Summarizes a set of stress absorbing layer scheme selection and test method of performance evaluation, for “white to black”engineering stress absorbed layer structure choice to provide theoretical reference.

  19. Hanford Protective Barriers Program asphalt barrier studies -- FY 1988

    International Nuclear Information System (INIS)

    The Hanford Protective Barrier (HPB) Program is evaluating alternative barriers to provide a means of meeting stringent water infiltration requirements. One type of alternative barrier being considered is an asphalt-based layer, 1.3 to 15 cm thick, which has been shown to be very effective as a barrier for radon gas and, hence, should be equally effective as a barrier for the larger molecules of water. Fiscal Year 1988 studies focused on the selection and formulation of the most promising asphalt materials for further testing in small-tube lysimeters. Results of laboratory-scale formulation and hydraulic conductivity tests led to the selection of a rubberized asphalt material and an admixture of 24 wt% asphalt emulsion and concrete sand as the two barriers for lysimeter testing. Eight lysimeters, four each containing the two asphalt treatments, were installed in the Small Tube Lysimeter Facility on the Hanford Site. The lysimeter tests allow the performance of these barrier formulations to be evaluated under more natural environmental conditions

  20. 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.

  1. Decontamination by shotblasting of radioactivity deposited on an asphalt road

    International Nuclear Information System (INIS)

    Long-lived fission products may be deposited in the environment after a serious reactor accident. From previous experiments it is known that if firehosing is to be used for decontamination it has to be done soon after the deposition. It is therefore worthwhile to study another decontamination method. An experimental study has been conducted of how well shotblasting can remove contamination from an asphalt road. In shotblasting a thin layer of the surface is loosened by the impact of small steel balls, and in the same procedure the surface dust is vacuumed up and the steel balls recovered. The contaminant was 86Rb, which behaves as caesium. As reference, the weathering of identical contamination on an asphalt road, a concrete road and a road covered with small concrete stones was studied concurrently. (author)

  2. 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...

  3. 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.

  4. 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.

  5. 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.

  6. Nuclear method for determination of asphalt content corrected for moisture in bituminous mixture. Final report, March 1988-February 1989

    International Nuclear Information System (INIS)

    This report presents results of research on the development of a method for determination of asphalt content corrected for moisture using the nuclear-gauge method. The researchers selected an approach that involved rapid drying of the asphalt concrete samples in a microwave oven prior to the determination of asphalt content using a Troxler Model 3241-C nuclear asphalt-content gauge. As a reference, asphalt contents were also measured using quantitative extraction. In general, good agreement was found between asphalt contents measured by the Troxler Model 3241-C nuclear gauge and asphalt contents measured by quantitative extraction. In extended sampling for Plant 1, no significant increase in nuclear gauge error was seen over a 10-day sampling period, which indicates that daily calibration of the nuclear gauge is probably unnecessary to maintain satisfactory performance. The field demonstration of the procedure of drying the bituminous mixture in a microwave oven and then determining its asphalt content by the nuclear method indicated asphalt-content results were obtained approximately 1 hour faster than results obtained by quantitative extraction

  7. Polymer Blends Modified Asphalt

    Institute of Scientific and Technical Information of China (English)

    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.

  8. 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

  9. Performance prediction of hot mix asphalt from asphalt binders

    International Nuclear Information System (INIS)

    Asphalt binder being a high weight hydrocarbon contains asphaltene and maltene and is widely used as cementing materials in the construction of flexible pavements. Its performance in hot mix asphalt also depends on combining with different proportions of aggregates. The main objective of this study was to characterize asphalt cement rheological behavior and to investigate the influence of asphalt on asphalt-aggregate mixtures prepared with virgin binders and using polymers. Binder rheology and mixtures stiffness were determined under a range of cyclic loadings and temperature conditions. Master curves were developed for the evaluation of relationship between parameters like complex modulus and phase angle at different frequencies. Horizontal shift factors were also computed to determine time and temperature response of binders and mixes. The results showed that the stiffness of both the binder and the mixes depends on temperature and frequency of load. Polymer modified binder is least susceptible to temperature variations as compared to other virgin asphalt cement. Performance of asphalt mixtures can be predicted from those of asphalt binders using the master curve technique. (author)

  10. 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.

  11. The effects of the chemical and radiolytic degradation of asphalt on plutonium solubility

    International Nuclear Information System (INIS)

    The influence of alkaline degradation or radiolytic degradation of asphalt on plutonium solubility has been investigated. Asphalt has been contacted with water, sodium hydroxide solution or concrete leachate at 80 C for periods of up to approximately 2 years. Sodium nitrate was also present in some of the experiments. Plutonium solubilities were measured at pH 12 in the leachates and found to be less than 10-8 mol/dm3 for most degradations. Relatively low levels of Total Organic Carbon were measured in the leachates. Alpha radiolysis of asphalt in the presence of concrete and water has also been studied. Samples of asphalt were encapsulated in concrete after coating with the 238PuO2, crushed and leached at room temperature. The solubility of plutonium was measured in samples of the leachates after approximately 90 days and 180 days had elapsed. The results showed that the solubility of plutonium in the α-radiolysis leachates remained low and was in the range 2 x 10-11 to 8 x 10-9 mol/dm3. A consideration of these results, and data published elsewhere, suggests that chemical and radiolytic attack on asphalt or bitumen under anaerobic, alkaline conditions typical of a deep cementitious repository is unlikely to generate complexants for plutonium which are effective at high pH. Any enhancement of plutonium solubility is likely to be less significant than that arising from the degradation of some other organic materials

  12. 连续配筋混凝土复合式沥青路面层间剪应力及结构%Interlaminar Shear Stress and Structure of Continuously Reinforced Concrete Composite Asphalt Pavement

    Institute of Scientific and Technical Information of China (English)

    李盛; 刘朝晖; 李宇峙

    2012-01-01

    针对连续配筋混凝土复合式沥青路面(CRC+AC)结构的特点和现有研究的不足,运用传热学理论、力学理论和有限元法,计算和分析了层间剪应力的临界荷位和影响因素;通过室内试验和工程实践,研究了基于层间剪应力的层间结构和材料及CRC层表面处理技术.研究结果表明:层间抗剪强度不足会使CRC+AC结构层间出现纵向和侧向滑移;层间最大剪应力随AC层厚度和模量的增大而减小,且随AC层厚度增加而减小的趋势更为明显,CRC层厚度对层间最大剪应力的影响很小;通过计算分析并结合试验路修筑经验和检测结果,建议CRC+AC结构AC层的厚度不宜小于6cm;建议采用喷洒式结构对CRC+AC结构的层间进行处理,并选用SBS改性沥青作为喷洒沥青,采用裸化技术对CRC层表面进行处理.研究结果可为刚柔复合式沥青路面的合理设计提供重要参考.%Focused on the characteristics and the flaws of existing studies of CRC + AC composite asphalt pavement structure, by using heat transfer theory, mechanics theory and finite element method, the critical * load position and the influencing factors of the interlaminar shear stress were calculated and analyzed. The interlaminar structure and materials, and CRC layer surface treatment technology based on interlaminar shear stress were researched by indoor experiment and engineering practice. The results show that (1) longitudinal and lateral slips would occur in CRC + AC structure due to lacking of interlaminar shear strength; (2 ) the interlaminar maximum shear stress decreases with the thickness and modulus of AC layer, and the decrease trend is more obvious with the increase of thickness of AC layer, the thickness of CRC layer has little effect on the interlaminar maximum shear stress. By analysis and calculating, and combined with measurment and construction experience of test road, it is recommended that the thickness of AC layer should

  13. Mix ratio design of asphalt concrete using GTM method based on LabVIEW%基于LabVIEW系统的GTM沥青混合料配合比设计

    Institute of Scientific and Technical Information of China (English)

    王丽君; 孙永成; 杨宗文

    2011-01-01

    应用LabVIEW虚拟仪器开发工具,实现对GTM沥青混合料配合比设计.通过软件强大的数据处理功能,控制系统可以自行运算,并将结果以报告的形式输出出来.主要开发了垂直压力、旋转角度、滚轮压力以及高度等标定程序,GTM试验控制系统程序的实现.通过GTM设计方法与马歇尔设计方法对比可知,两种方法各有优缺点.但是,由GTM设计的沥青混合料比马歇尔设计的沥青混合料的路用性能高,GTM设计方法比较适用于重载道路路面设计.%Application virtual instrument of Lab VIEW to realize the GTM asphalt mixture design. Through the powerful data processing software,the results are reported by the control system on their own calculation. In this paper,a vertical pressure,rotation angles,roller pressure and height calibration programs are programmed. Meanwhile the GTM test control system with program is developed. Comparison the GTM design method with the Marshall design method,two methods each have their own advantages and disadvantages. But the asphalt mixture designed by the GTM has higher expressway performance than that designed by the Marshall design method. The GTM design method is more suitable for heavy load pavement.

  14. 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.

  15. 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

  16. Preparation and properties of montmorillonite modified asphalts

    International Nuclear Information System (INIS)

    Modified asphalts were prepared by melt blending with different contents of montmorillonite (MMT) and organomodified montmorillonite (OMMT). The X-ray diffraction (XRD) results show that the MMT modified asphalt may form an intercalated structure, whereas the OMMT modified asphalt may form an exfoliated structure. The addition of MMT and OMMT to asphalt increases both the softening point and viscosity of the modified asphalts at high temperatures. Furthermore, the modified asphalts exhibited higher complex modulus, lower phase angle. As a consequence, the MMT and OMMT modified asphalts displays enhanced viscoelastic properties, which improve its resistance to rutting at high temperatures. Compared with MMT, OMMT showed better effect in improving softening point and rutting resistance of asphalt, which contributes to the formation of exfoliated structure in OMMT modified asphalt. Storage stability tests disclose that the asphalts modified with MMT or OMMT are very stable when montmorillonite content is less than 3 wt%

  17. Asphalt as biological shielding against fusion neutrons

    International Nuclear Information System (INIS)

    For fusion experiments, thick biological radiation protection shields are necessary due to the deep penetration capability of the 14 MeV neutrons. A (D,T) neutron generator with a moderate output of around 1012 n/sec requires a concrete shielding of a wall thickness of 2 meters laterally and at the top of an experimental assembly. The cost for this biological shield may exceed the cost for most of the equipment for a fusion and/or hybrid experimental installation. Particularly, in Saudi Arabia, asphalt is very cheap and available in bulk quantities. As it is rich in hydrogen and carbon, it is worthwhile to investigate its shielding potential against fusion neutron. In the present work different biological shield configurations of asphalt at the wall of the experimental cavity for a research program being undertaken in Saudi Arabia, are investigated. The experimental cavity is approximated by a sphere of 5 meters radius. The yield of the neutron generator is taken as 1012 - 14 MeV - neutron/sec

  18. Effects of Mineral Filler to Polymer Modified Bitumen Ratio on the Design Properties of Hot Mix Asphalt and its Performance

    OpenAIRE

    Imran Hafeez; MUMTAZ AHMED KAMAL

    2010-01-01

    Current development in the design of asphalt concrete especially in the upper layers of flexible pavements contains about acceptable proportion of mineral fillers passing 75?m (# 200) sieve, which contributes towards the mix cohesion, resistant to rutting and improves serviceability. Three filler to PMA (Polymer Modified Asphalt) ratios (i.e. 2.4, 3.4. and 4.4%) in Marshall Method of mix design were used in order to determine the optimum filler content at relatively low design ...

  19. 材料粘弹性对沥青混凝土钢桥面铺装结构疲劳寿命预估的影响%Influences of Viscoelasticity of Materials on Estimate of Fatigue Life of Pavement Structure of Asphalt Concrete Steel Deck

    Institute of Scientific and Technical Information of China (English)

    任开亮; 黄天贵; 赵国云

    2015-01-01

    为研究材料粘弹性对钢桥面浇注式沥青混凝土铺装结构疲劳寿命预估结果的影响,建立粘弹性有限元模型,分析不同荷载作用次数下铺装结构表面拉应变的变化规律,并基于应变控制的铺装面层混凝土疲劳方程预估铺装的使用寿命。结果表明:由于受材料粘弹性特性影响,随着荷载作用次数增加,钢桥面铺装表面拉应变也随之增大,铺装疲劳寿命降低;荷载作用20000次前变化更为明显,其后则趋于平缓。%In order to research influences of viscoelasticity of materials on estimate of fatigue life of pavement structure of asphalt concrete steel deck,this paper establishes a viscoelasticity finite element model and analyzes change rules of tensile strain on the surface of pavement structure at different action times of load,and estimates the service life of pavement based on strain controlled fatigue equation of surface concrete of pavement.The results show that the tensile strain on the surface of steel deck pavement increases with more action times of load due to influence of viscous and elastic properties,and fatigue life of pavement decreases;the change before 20 000 action times of load is more significant,and then becomes flat.

  20. Effects of Mineral Filler to Polymer Modified Bitumen Ratio on the Design Properties of Hot Mix Asphalt and its Performance

    Directory of Open Access Journals (Sweden)

    Imran Hafeez

    2010-10-01

    Full Text Available Current development in the design of asphalt concrete especially in the upper layers of flexible pavements contains about acceptable proportion of mineral fillers passing 75?m (# 200 sieve, which contributes towards the mix cohesion, resistant to rutting and improves serviceability. Three filler to PMA (Polymer Modified Asphalt ratios (i.e. 2.4, 3.4. and 4.4% in Marshall Method of mix design were used in order to determine the optimum filler content at relatively low design asphalt contents (3.83%, for asphalt concrete having PMA and 100% lime stone dust. Designed mix was laid on Southbound Turnol Taxila National Highway Section (N-5, Pakistan as a trial in year 2003. The study reveals that filler to asphalt ratio affects the mix properties to a greater extent and mix laid at site have shown relatively better performance during its service life of initial four critical years. For coarse graded mixes with low asphalt contents, designed especially for heavy loading and high temperatures regions like Pakistan, filler to asphalt ratio less than equal to 1.0 yields better results.

  1. 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.  ……

  2. 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,

  3. Study on Influence Factors of Anti-shear Performance of High Grade Asphalt Concrete Pavement%高等级沥青混凝土路面抗剪性能影响因素研究

    Institute of Scientific and Technical Information of China (English)

    王志强

    2014-01-01

    Based on the multilayered elastic system theory and the GAMES software,considering the thickness of pavement structure courses,the stiffness and the interface condition,the paper analyzed the change law of anti-shear performance of the asphalt pavement.The results show that:the effect of the thickness of the surface course and the base course on the asphalt pavement is insignificant,so it is a waste of cost to increase the thickness of the surface course and the base course to enhance the shearing capability;the shear stress peak value in the surface course would be reduced by increasing the modulus of base course,but the change is not obvious,which indicates that it does little to promote the anti-shear performance by increasing the modulus of base course;the more the modulus ratio between the wearing course and the mid-course,the greater the shear stress peak value in the surface course,which can be ob-viously seen;the shear stress peak value in the surface course would be reduced by the decrease of inter-facial bonding performance.%运用多层弹性体系理论,以 GAMES 软件为力学分析工具,考虑路面结构层厚度、基面层模量及层间状态等因素,分析沥青路面抗剪性能的变化规律。结果表明:沥青路面剪应力峰值受面层厚度和基层厚度影响不明显,通过增加面层厚度和基层厚度提高路面抗剪性能加重了经济成本,收效甚微;面层内剪应力峰值随基层模量增加而减小,但变化不明显,说明增加基层模量对沥青路面抗剪性能的提高作用不大;上面层与中面层模量比越大,上面层内剪应力峰值越大,且这种影响较为明显;在层间粘结减弱的过程中,面层内最大剪应力峰值随之减小。

  4. 高速公路沥青砼铣刨料在预防性养护中的应用%Application of Asphalt Concrete Milling Planer Material in the Preventive Maintenance of Expressway

    Institute of Scientific and Technical Information of China (English)

    武多亮

    2015-01-01

    In the daily maintenance of highway, to improve the efficiency of resource utilization, reduce maintenance costs and reduce environmental pollution and then make the highway maintenance in accordance with the natural environment is the goal and direction of the exploration in the highway preventive maintenance. This paper mainly expounds how to use the waste asphalt mixture materials of milling and planer in the maintenance repair operations of the highway and puts forward the related technical measures for the preventive treatment of the pavement diseases of the low grade highway.%在公路日常养护中如何提高资源利用效率,降低养护成本,减少环境污染,进而使公路养护与自然环境相和谐,是公路预防性养护中所探索的目标和方向。本文重点阐述了如何利用高速公路养护维修作业中铣刨的废旧沥青混合料,对低等级公路的路面病害进行预防性处治的相关技术措施。

  5. 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,…

  6. 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.

  7. 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.

  8. Self Healing Capacity of Asphalt Binders

    Institute of Scientific and Technical Information of China (English)

    PANG Ling; JIANG Huan; WU Shuxiang; WU Shaopeng

    2012-01-01

    To test self healing capability of asphalt binders,three asphalt specimens (pure asphalt,modified asphalt and aged asphalt) were prepared.Every specimen was tested by dynamic shear rheometer (DSR).The temperature sweeps result indicates that both aging and SBS modifying influence the self healing capability of asphalt binder.The fatigue-heal-fatigue test was introduced to study the self healing capability of asphalt in its serving periods.Furthermore,three different periods (0.5 h,1 h,3 h) were set up to study the influence of rest time on fatigue time.It is concluded that longer rest time,less load will delay the appearance of cracks and extend the service life of asphalt binders.

  9. 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.

  10. Laboratory aging of asphalt mixtures : simulation of reclaimed asphalt and application as test method for durability

    OpenAIRE

    Mollenhauer, Konrad; MOUILLET, Virginie; PIERARD, Nathalie; TUSAR, Marjan; Gabet, Thomas

    2012-01-01

    Surface asphalt courses reach their end of service life after a time span between 10 and 30 years, depending on their durability. Afterwards, the surface layer is usually milled and reused in asphalt mixtures as reclaimed asphalt. In order to enable the analysis of durability and recyclability of a new asphalt mixture, four laboratory aging procedures were designed and comparatively applied on twoasphalt mixes. Besides aging of loose asphalt mix in heating cabinets at varied temperatures and ...

  11. Laboratory optimization of continuous blend asphalt rubber

    OpenAIRE

    Fontes, Liseane P. T. L.; Pereira, Paulo A. A.; Trichês, Glicério; Pais, Jorge C.; Luzia, Rosa

    2008-01-01

    Asphalt rubber from wet process requires batching blending and reaction time associated to blending rubber and conventional asphalt to produce asphalt rubber. The ideal blending of these materials depends on the combination of very important variables, such as the amount of rubber, reaction time and temperature reaction. This paper intends to optimize the laboratory production of asphalt rubber using the continuous blend process. The rubber from waste tyres was reduced by ambient grinding and...

  12. Evaluating permanent deformation in asphalt rubber mixtures

    OpenAIRE

    Fontes, Liseane P. T. L.; Trichês, Glicério; Pais, Jorge C.; Pereira, Paulo A. A.

    2009-01-01

    Permanent deformation or rutting, one of the most important distresses inflexible pavements, has long been a problem in asphalt mixtures. Throughout the years, researchers have used different test methods lo estimate the performance of asphalt mixtures in relation to rutting. One of the alternatives to reduce permanent deformation in asphalt pavement layers is through the use of mixtures produced with asphalt rubber This work aims at comparing the performance of a conventional dense graded mi...

  13. Asphalt Carriers from Kraljevica Shipyard, Croatia

    OpenAIRE

    Grubišić, R.

    2006-01-01

    This article is based on the materials presented by the experts from Kraljevica Shipyard at the annual meeting of the Croatian shipbuilding designers held in Kraljevica in October 2005. Asphalt tanker Asphalt Seminole and her sister-ships are rather sophisticated vessels having a complex hull structure, cargo space and cargo survey and control equipment. Therefore, firstly the technical data of the already delivered asphalt tanker Asphalt Seminole are given and then, the very interesting d...

  14. 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.

  15. 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.

  16. 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...

  17. Initiative assessment of asphalt works

    International Nuclear Information System (INIS)

    Several asphalt works are utilizing heat from combustion of used oil for drying and heating of rock material in the production of asphalt. According to new regulations on combustion of waste, used oil is to be regarded as waste and subject to emission requirements according to the combustion regulations. Measurements show that emissions of CO, dust, dioxins, TOC and SO2 exceed the limits set by the regulations. To conform to the regulations these asphalt works must improve their combustion technique. However, such measures may lead to increased formation of NOx. It is recommended that a combustion chamber for drying of rock material should be used in order to reduce the emissions of CO and TOC concentrations. The concentration of SO2 may be reduced by dry cleaning by means of injection of lime. In the same way, active carbon is injected to remove dioxins. The asphalt works must be outfitted with measuring equipment that monitors and records certain operation and control parameters and some emission to air parameters. Periodic measurements are to be done of heavy metals and dioxins. It is estimated that the measures necessary to make the asphalt works comply with the regulations will cost about NOK 4 530 000 in investment per plant and that the operation expenses will increase by NOK 700 000 per year per plant. This includes maintenance, control etc

  18. Evaluation and Study the Effect of Additives and Other Factors on Tensile Strength of Asphalt Paving Mixtures

    Directory of Open Access Journals (Sweden)

    Hanaa Khaleel A. Al-Baiti

    2012-03-01

    Full Text Available The resistance of asphaltic concrete to cracking is dependent upon its tensile strength and flexibility characteristics. Also the low tensile strength has recognized as a major contributor to other performance problems. The fatigue life of mixtures decreases exponentially with decreasing of tensile strength. This trend is justified by the loss in stiffness and thereby initiating cracks and stripping. The main objective of this research is intended to study the effect of different variables related with the used materials and the external conditions on the tensile strength and predict a model of indirect tensile strength in asphalt concrete paving materials under the local prevailing conditions and investigate the effect of percent of additives of (Polyestrene resins and Hydrated Lime to enhance the resistance ability of asphalt concrete mixture against distresses. The main affected factors; soaking, asphalt content, compaction, aggregate maximum size and temperature, influence on the indirect tensile strength and presented through a statistics analysis model for tensile strength in asphalt mixture

  19. 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。

  20. Waterproofing improvement of radioactive waste asphalt solid

    International Nuclear Information System (INIS)

    Purpose: To improve the waterproofing of asphalt solid by adding an alkaline earth metal salt and, further, paraffin, into radioactive liquid waste when processing asphalt solidification of the radioactive liquid waste. Method: Before processing molten asphalt solidification of radioactive liquid waste, soluble salts of alkaline earth metal such as calcium chloride, magnesium chloride, or the like is added to the radioactive liquid waste. Paraffin having a melting point of higher than 600C, for example, is added to the asphalt, and waterproofing can be remarkably improved. The waste asphalt solid thus fabricated can prevent the swelling thereof, and can improve its waterproofing. (Yoshihara, H.)

  1. Thermal behavior of asphalt cements

    International Nuclear Information System (INIS)

    Asphalt cements are highly complex mixtures of hydrocarbon molecules whose thermal behavior is of prime importance for petroleum and road industry. From DSC, the determination of several thermal properties of asphalts is given, e.g. glass-transition temperature and crystallized fraction content.The dissolution of a pure n-paraffin CnH2n+2 in an asphalt, as seen by DSC, should be a single peak. For 20g of these glasses change with time and temperature. The formation of the crystallized phases is superposed to the enthalpic relaxation of the glasses, making a kinetic study very difficult. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  2. Research on the Technology Applying Anti-Rutting Additive to Asphalt Mixture

    Science.gov (United States)

    Sun, Jie; Huang, Liming; Li, Chun

    High-temperature problems like rutting, displacement and upheaval are the most serious ones for bituminous pavement of urban roads. Especially, such problems at crossroads and fixed places where buses stop, for instance, BRT, affect service ability and life of roads largely. Application of anti-rutting asphalt mixture mainly aims at reducing strain and deformation generated by bituminous concrete under effect of vehicle load, decreasing remainders that cannot be recovered in deformation, improving the ability of bituminous pavement to resist deformation under high temperature and delaying generation of rutting. Anti-rutting asphalt mixture in this thesis refers to the asphalt mixture where anti-rutting additive is added by dry method and high-temperature stability is improved.

  3. Analysis and Application of Hot In-Plant Recycling Technology for Asphalt Concrete%沥青混凝土厂拌热再生技术的分析及其应用

    Institute of Scientific and Technical Information of China (English)

    韩青春; 王力博

    2012-01-01

    Application of hot in-plant recycling technology in Changchun-Siping Expressway is introduced.On account of different layer and aging conditions,experimental study for hot in-plant recycling is performed.Construction technology and technical features of hot in-plant recycling technology in surface course construction of expressway are concluded.Through technical and economic comparison,the result shows that hot in-plant recycled concrete could reach the same performance as the pavement paved with 100% new material through reasonable design and construction.%介绍了厂拌热再生技术在长春至四平高速公路中的应用。针对不同层位、不同老化条件下,进行厂拌热再生试验研究,对厂拌热再生技术在高速公路面层施工中的施工工艺和技术特点进行了总结。经过技术经济比较,结果表明通过合理的设计与施工厂拌热再生混凝土可以达到与100%使用新材料铺筑的路面一样的使用性能的结论。

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. Rheological characteristics of aged asphalt binder

    Institute of Scientific and Technical Information of China (English)

    刘聪慧; 吴少鹏; 刘全涛; 朱国军

    2008-01-01

    Different aging levels(RTFOT,PAV-10h,PAV-20h and PAV-30 h) of asphalt binders with various mass ratios of mineral powder to asphalt(0,0.4,0.8,1.2,1.6,2.0) were used to investigate the rheological properties of aged asphalt binders with respect to their short and long terms aging characteristics.Viscosity test,dynamic shear test and creep test were conducted.The test results indicate that the viscosity of aged asphalt binder increases sharply with the extension of aging period.Complex shear modulus of aged asphalt increases,which indicates that the stiffness of asphalt binders can increase.The phase angle for aged asphalt binders reduces,which indicates that the elastic portion for viscoelastic property of asphalt binders increases.|G*|·sin δ increases after aging procedure which means that the fatigue resistance becomes poor.The creep test results show that creep strain curves varies remarkably for virgin and aged asphalt binders.The total strain during loading period and the permanent strain decreases significantly for aged asphalt binders,which implies that the elastic portion increases and the viscous portion decreases.

  9. Evaluation of Marshall Properties of Warm Mix Asphalt using Sasobit

    OpenAIRE

    Renugadevi. A

    2014-01-01

    With increasing concerns of global warming and increasing exhaustion of greenhouse gases, the asphalt industry is looking for alternatives for hot mix asphalt (HMA).Warm Mix Asphalt (WMA) is a fast emerging new technology which has a potential of revolutionizing the production of asphalt mixtures. WMA technology allows the mixing, lay down and compaction of asphalt mixes at significantly lower temperatures compared to Hot Mix Asphalt (HMA). The technology can reduce production tem...

  10. Laboratory test methods for polishing asphalt surfaces and predicting their skid resistance

    OpenAIRE

    Do, Minh Tan; Kane, Malal; Cerezo, Véronique

    2013-01-01

    In this paper, laboratory test methods reproducing phenomena affecting pavement skid resistance evolution are presented. Polishing tests are performed by Wehner/Schulze machine to simulate the polishing induced by traffic and the binder removal phase (typical for bituminous asphalt concrete). Accelerated aging tests are performed by a weatherometer, operating conditions being adjusted according to local weather conditions, to simulate the binder aging responsible for friction increase at earl...

  11. 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.

  12. Microstructural characterisation of rubber modified asphalt mixtures

    OpenAIRE

    Abdul Hassan, Norhidayah

    2013-01-01

    Research to improve the performance of asphalt mixtures through the addition of crumb rubber using the dry process has continued worldwide because of its potential as a recycling option for used tires. For decades, dry mixed rubberised asphalt mixtures have performed inconsistently in field trials and laboratory evaluations. However, current research has revealed that the performance of asphalt mixtures is highly dependent on the characteristics of its internal structure or phase constituents...

  13. Construction and maintenace of porous asphalt

    OpenAIRE

    Kert, Gregor

    2012-01-01

    In improving traffic safety and reducing traffic noise road building experts from Slovenia and the world are faced with permeable surfaces - namely porous asphalt. There is hardly any water retention on road surfaces with the use of porous asphalt, what Slovenian engineers efficiently use on motorways where transverse profile changes its direction. Lately, porous asphalt is also being used for traffic noise reduction. However, porous road surface has some important disadvantages due to its...

  14. Asphalt solar collectors: A literature review

    OpenAIRE

    Bobes-Jesús, Vanesa; Pascual Muñoz, Pablo; Castro Fresno, Daniel; Rodríguez Hernández, Jorge

    2013-01-01

    Asphalt pavements subject to solar radiation can reach high temperatures causing not only environmental problems such as the heat island effect on cities but also structural damage due to rutting or hardening as a result of thermal cycles. Asphalt solar collectors are doubly effective active systems: as they solve the previously mentioned problems and, moreover, they can harness energy to be used in different applications. The main findings of the existing research on asphalt solar collectors...

  15. Thermal stability analysis under embankment with asphalt pavement and cement pavement in permafrost regions.

    Science.gov (United States)

    Junwei, Zhang; Jinping, Li; Xiaojuan, Quan

    2013-01-01

    The permafrost degradation is the fundamental cause generating embankment diseases and pavement diseases in permafrost region while the permafrost degradation is related with temperature. Based on the field monitoring results of ground temperature along G214 Highway in high temperature permafrost regions, both the ground temperatures in superficial layer and the annual average temperatures under the embankment were discussed, respectively, for concrete pavements and asphalt pavements. The maximum depth of temperature field under the embankment for concrete pavements and asphalt pavements was also studied by using the finite element method. The results of numerical analysis indicate that there were remarkable seasonal differences of the ground temperatures in superficial layer between asphalt pavement and concrete pavement. The maximum influencing depth of temperature field under the permafrost embankment for every pavement was under the depth of 8 m. The thawed cores under both embankments have close relation with the maximum thawed depth, the embankment height, and the service time. The effective measurements will be proposed to keep the thermal stabilities of highway embankment by the results. PMID:24027444

  16. Asphalt solar collectors: A literature review

    International Nuclear Information System (INIS)

    Highlights: ► Solar energy can be harnessed by asphalt pavements. ► Research on asphalt thermal behavior and asphalt solar collectors is reviewed. ► Asphalt temperature is very sensitive to the variation of absortivity. ► Asphalt solar collector efficiency depends on flow rate and geometrical parameters. -- Abstract: Asphalt pavements subject to solar radiation can reach high temperatures causing not only environmental problems such as the heat island effect on cities but also structural damage due to rutting or hardening as a result of thermal cycles. Asphalt solar collectors are doubly effective active systems: as they solve the previously mentioned problems and, moreover, they can harness energy to be used in different applications. The main findings of the existing research on asphalt solar collectors are gathered together in this review paper. Firstly, the main heat transfer mechanisms involved in the solar energy collection process are identified and the most important parameters and variables are presented. After analyzing the theoretical foundations of the heat transfer process, this review focuses on the types of studies carried out so far on asphalt’s thermal behavior, different methodologies employed by other authors to study asphalt solar collectors and influence of the variables involved in thermal energy harvesting.

  17. Impact of defective production of asphalt mixture resulting in damaged asphalt layers

    OpenAIRE

    Hrovat, Tea

    2013-01-01

    In practice it often happens that a newly built road soon, after the asphalt mixture is added, starts showing first cracks and damages, which are not necessarily always a fault of the contractor, who built in the asphalt mixture, but can derive from the production of asphalt mixture. Such mistakes in the production of the asphalt mixture are hard to prove, since all the contractors usually put the blame on the automatic mixing production in the asphalt plant. During the production of the asph...

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

    OpenAIRE

    Ana Sofía Figueroa Infante; Fredy Alberto Reyes Lizcano; Diana Hernández Barrera; Christian Jiménez; Natalia Bohórquez

    2010-01-01

    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, 15...

  19. 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...

  20. Rheological characterization of aged asphalts

    International Nuclear Information System (INIS)

    The present work shows the rheological properties of the three Colombian asphalts produced in the refineries at Barrancabermeja, Cartagena and Apiay, exposed to the open air during 18 months using a specially designed testing bank. rheological behavior was evaluated using the new specifications of SHRP technology in the Brookfield and DSR rheometers to determine viscosity, shear stress, shear rate, dynamic share modulus and other related variables. The measurements were made using different temperatures and load times

  1. Asphalt solidification of mixed wastes

    International Nuclear Information System (INIS)

    Mixed wastes pose a problem to generators since there are no burial sites or treatment facilities currently accepting this waste type. One potential disposal method is treating the waste to render it non-hazardous, and disposing of it in accordance with radioactive waste requirements. A possible means of accomplishing this transformation is solidifying the waste in asphalt (bitumen). Associated Technologies Incorporated, in cooperation with Oak Ridge National Laboratory, solidified in asphalt a surrogate sodium nitrate-based waste, spiked with EPtoxic metals and non-radioactive cesium and strontium. This paper reports the characteristics of the spiked ORNL solution that was solidified as well as the properties of the solidified end product. The waste samples generated underwent EP toxicity testing as well as ANS 16.1 leach testing for 90 days and the results of those tests are presented. Also, a discussion of the criteria for classifying a waste as hazardous are included in order to demonstrate that the waste, once solidified in asphalt, may no longer be considered hazardous

  2. 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.

  3. Structural Precast Concrete Handbook

    DEFF Research Database (Denmark)

    Kjærbye, Per Oluf H

    Structural concept for precast concrete systems. Design og precast reinforced concrete components. Design of precast concrete connections. Illustrations on design of precast concrete buildings. Precast concrete assembly....

  4. Design and construction of Nemiscau-1 Dam, the first asphalt core rockfill dam in North America

    Energy Technology Data Exchange (ETDEWEB)

    Alicescu, V.; Tournier, J.P. [Hydro-Quebec, Montreal, PQ (Canada); Vannobel, P. [Societe d' Energie de la Baie James, Montreal, PQ (Canada)

    2008-07-01

    The concept of asphalt as a waterproofing medium inside embankment dams was originally developed in Germany in the 1960s. More than 100 asphalt core rockfill (ACRD) dams have been completed or are under construction. They all have a strong record without any seepage problems or required maintenance. After using the glacial till as waterproofing material for its embankment dams for more than 50 years, Hydro-Quebec is now looking to develop new dam concepts, mainly for the zones where natural waterproofing materials do not exist. In order to do so, the company has decided to design and construct the Nemiscau-1 Dam as a prototype ACRD. This paper presented the detailed design criteria, technical specifications as well as some information concerning the construction of the dam such as asphalt mix design. The given dam site, geology and materials is well suited for a dam with an asphalt core and the chosen core thickness of minimum 400 mm was found to be appropriate, given the small net water head. The main reservoir levels as well as the characteristics of the dam were also listed. Information on the general construction of the dam was provided. It was concluded that the longitudinal profile of the rock excavation and concrete plinth must be optimized, with an optimum balance between the rock excavation, the volume and shape of the concrete plinth and finally, the placement of the asphalt core with the manual method. Several combinations of these 3 elements must be analyzed at the design stage and the most cost effective one should be applied on site. 5 tabs., 7 figs.

  5. Experimental investigation of basic oxygen furnace slag used as aggregate in asphalt mixture.

    Science.gov (United States)

    Xue, Yongjie; Wu, Shaopeng; Hou, Haobo; Zha, Jin

    2006-11-16

    Chinese researchers have commenced a great deal of researches on the development of application fields of basic oxygen steel making furnace slag (BOF slag) for many years. Lots of new applications and properties have been found, but few of them in asphalt mixture of road construction engineering. This paper discussed the feasibility of BOF steel slag used as aggregate in asphalt pavement by two points of view including BOF steel slag's physical and micro-properties as well as steel slag asphalt materials and pavement performances. For the former part, this paper mainly concerned the mechanochemistry and physical changes of the steel slag and studied it by performing XRD, SEM, TG and mercury porosimeter analysis and testing method. In the second part, this paper intended to use BOF steel slag as raw material, and design steel slag SMA mixture. By using traditional rutting test, soak wheel track and modified Lottman test, the high temperature stability and water resistance ability were tested. Single axes compression test and indirect tensile test were performed to evaluate the low temperature crack resistance performance and fatigue characteristic. Simultaneously, by observing steel slag SMA pavement which was paved successfully. A follow-up study to evaluate the performance of the experimental pavement confirmed that the experimental pavement was comparable with conventional asphalt pavement, even superior to the later in some aspects. All of above test results and analysis had only one main purpose that this paper validated the opinion that using BOF slag in asphalt concrete is feasible. So this paper suggested that treated and tested steel slag should be used in a more extensive range, especially in asphalt mixture paving projects in such an abundant steel slag resource region. PMID:16982138

  6. 橡胶沥青路面的结构类型及应用%The structure type and application of rubber asphalt pavement

    Institute of Scientific and Technical Information of China (English)

    赵评宏

    2015-01-01

    This paper discussed two kinds of production technology of rubber asphalt,analyzed the technical advantages of rubber asphalt,intro-duced the main structure types of rubber asphalt applied in pavement,and discussed the characteristics of gap gradation rubber asphalt concrete, rubber asphalt stone mastic,rubber asphalt stress absorbing layer,put forward the research direction improvement of rubber asphalt performance.%论述了橡胶沥青的两种生产工艺,分析了橡胶沥青具有的技术优势,介绍了橡胶沥青应用于路面的主要结构类型,并对断级配橡胶沥青混凝土、橡胶沥青玛脂碎石、橡胶沥青应力吸收层的特性进行了探讨,提出了完善橡胶沥青性能的研究方向。

  7. Hot Mix Asphalt Recycling: Practices and Principles

    NARCIS (Netherlands)

    Mohajeri, M.

    2015-01-01

    Hot mix asphalt recycling has become common practice all over the world since the 1970s because of the crisis in oil prices. In the Netherlands, hot recycling has advanced to such an extent that in most of the mixtures more than 50% of reclaimed asphalt (RA) is allowed. These mixtures with such a hi

  8. EVALUATION OF EMISSIONS FROM PAVING ASPHALTS

    Science.gov (United States)

    The report provides data from pilot-scale measurements of the emissions of specific air pollutants from paving asphalt both with and without recycled crumb rubber additives. The methods used in this work measured emissions from a static layer of asphalt maintained for several hou...

  9. EVALUATION OF EMISSION FROM PAVING ASPHALTS

    Science.gov (United States)

    The report provides data from pilot-scale measurements of the emissions of specific air pollutants from paving asphalt both with and without recycled crumb rubber additives. he methods used in this work measured emissions from a static layer of asphalt maintained for several hour...

  10. Asphalt Raking. Instructor Manual. Trainee Manual.

    Science.gov (United States)

    Laborers-AGC Education and Training Fund, Pomfret Center, CT.

    This packet consists of the instructor and trainee manuals for an asphalt raking course. The instructor manual contains a course schedule for 4 days of instruction, content outline, and instructor outline. The trainee manual is divided into five sections: safety, asphalt basics, placing methods, repair and patching, and clean-up and maintenance.…

  11. Environmental Benefits of Warm Mix Asphalt

    OpenAIRE

    Zaumanis, M; OLESEN, E

    2010-01-01

    WMA is a relatively new technology that allows significant lowering of the production and pavement temperature of conventional hot mix asphalt (HMA). It promises various benefits, but probably the most significant is the possibility to reduce carbon footprint of asphalt thus supporting the demands of Kyoto protocol for lowering greenhouse gas emissions in the atmosphere.

  12. 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.

  13. Environmental Benefits of Warm Mix Asphalt (WMA)

    OpenAIRE

    Zaumanis, M; Olesen, E

    2010-01-01

    Warm Mix Asphalt technology promises various benefits, but probably the most significant is the possibility to reduce carbon footprint of asphalt. The degree of emission reduction depends on the production technology, therefore life cycle assessment tool is vital to calculate the benefits and compare technologies.

  14. Pervious Concrete

    OpenAIRE

    Torsvik, Øyvind André Hoff

    2011-01-01

    Pervious concrete is a type of concrete with little or no fines which give a large void. This enables high permeability and because of this it enables water to percolate through the concrete. Pervious concrete have been used in many years both as pavement material and on several other applications in the U.S and in other countries in Western Europe. In Norway pervious concrete is not currently in use. This thesis aims to investigate if pervious concrete can withstand the harsh Norwegian clima...

  15. Curing Reaction Model of Epoxy Asphalt Binder

    Institute of Scientific and Technical Information of China (English)

    QIAN Zhendong; CHEN Leilei; WANG Yaqi; SHEN Jialin

    2012-01-01

    In order to understand the strength developing law of the epoxy asphalt mixture,a curing reaction model of the epoxy asphalt binder was proposed based upon the thermokinetic analysis.Given some assumptions,the model was developed by applying the Kissinger law as well as Arrhenius equation,and the differential scanning calorimetry was performed for estimating the model parameters.To monitor the strength development of the epoxy asphalt mixture,a strength test program was employed and then results were compared to those produced from the proposed model.The comparative evaluation shows that a good consistency exists between the outputs from test program and the proposed model,indicating that the proposed model can be used effectively for simulating the curing reaction process for the epoxy asphalt binder and predicting the strength development for the epoxy asphalt mixture.

  16. A Methodology for Determination of Resilient Modulus of Asphaltic Concrete

    Directory of Open Access Journals (Sweden)

    A. Patel

    2011-01-01

    Full Text Available Resilient modulus, , is an important parameter for designing pavements. However, its determination by resorting to cyclic triaxial tests is tedious and time consuming. Moreover, empirical relationships, correlating to various other material properties (namely, California Bearing Ratio, CBR; Limerock Bearing Ratio, LBR; R-value and the Soil Support Value, SSV, give vast variation in the estimated results. With this in view, an electronic circuitry, which employs bender and extender elements (i.e., piezo-ceramic elements, was developed. Details of the circuitry and the testing methodology adopted for this purpose are presented in this paper. This methodology helps in determining the resilient modulus of the material quite precisely. Further, it is believed that this methodology would be quite useful to engineers and technologists for conducting quality check of the pavements, quite rapidly and easily.

  17. 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

  18. 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.

  19. Strain transfer analysis of optical fiber based sensors embedded in an asphalt pavement structure

    Science.gov (United States)

    Wang, Huaping; Xiang, Ping

    2016-07-01

    Asphalt pavement is vulnerable to random damage, such as cracking and rutting, which can be proactively identified by distributed optical fiber sensing technology. However, due to the material nature of optical fibers, a bare fiber is apt to be damaged during the construction process of pavements. Thus, a protective layer is needed for this application. Unfortunately, part of the strain of the host material is absorbed by the protective layer when transferring the strain to the sensing fiber. To account for the strain transfer error, in this paper a theoretical analysis of the strain transfer of a three-layered general model has been carried out by introducing Goodman’s hypothesis to describe the interfacial shear stress relationship. The model considers the viscoelastic behavior of the host material and protective layer. The effects of one crack in the host material and the sensing length on strain transfer relationship are been discussed. To validate the effectiveness of the strain transfer analysis, a flexible asphalt-mastic packaged distributed optical fiber sensor was designed and tested in a laboratory environment to monitor the distributed strain and appearance of cracks in an asphalt concrete beam at two different temperatures. The experimental results indicated that the developed strain transfer formula can significantly reduce the strain transfer error, and that the asphalt-mastic packaged optical fiber sensor can successfully monitor the distributed strain and identify local cracks.

  20. Aging Influence on Fatigue Characteristics of RAC Mixtures Containing Warm Asphalt Additives

    Directory of Open Access Journals (Sweden)

    Feipeng Xiao

    2010-01-01

    Full Text Available Aging is an important factor to affect the long-term performance of asphalt pavement. The fatigue life of a typical warm mix asphalt (WMA is generally related to various factors of rheological and mechanical properties of the mixture. The study of the fatigue behavior of the specific rubberized WMA is helpful in recycling the scrap tires and saving energy in terms of the conventional laboratory aging process. This study explores the utilization of the conventional fatigue analysis approach in investigating the cumulative dissipated, stiffness, and fatigue life of rubberized asphalt concrete mixtures containing the WMA additive after a long-term aging process. The aged beams were made with one rubber type (−40 mesh ambient crumb rubber, two aggregate sources, two WMA additives (Asphamin and Sasobit, and tested at 5 and 20ºC. A total of 55 aged fatigue beams were tested in this study. The test results indicated that the addition of crumb rubber extends the fatigue resistance of asphalt binder while WMA additive exhibits a negative effect. The study indicated that the WMA additive generally has an important influence on fatigue life. In addition, test temperature and aggregate source play an important role in determining the cumulative dissipated energy, stiffness, and fatigue life of an aged mixture.

  1. Strength Mechanism and Influence Factors for Cold Recycled Asphalt Mixture

    OpenAIRE

    Tao Ma; Hao Wang; Yongli Zhao; Xiaoming Huang; Yuhui Pi

    2015-01-01

    This study focused on the key factors affecting the tensile strength of cold recycled asphalt mixture with cement and emulsified asphalt. The specific surface areas and strength of RAP were analyzed. The interaction between the emulsified asphalt and cement was observed. Comprehensive laboratory testing was conducted to evaluate the influences of RAP, emulsified asphalt, and cement on the tensile strength of cold recycled asphalt mixture. It is found that although RAP is used as aggregates, i...

  2. Road pavers' occupational exposure to asphalt containing waste plastic and tall oil pitch.

    Science.gov (United States)

    Väänänen, Virpi; Elovaara, Eivor; Nykyri, Erkki; Santonen, Tiina; Heikkilä, Pirjo

    2006-01-01

    Waste plastic (WP) and tall oil pitch (T), which are organic recycled industrial by-products, have been used as a binder with bitumen in stone mastic asphalt (SMA) and asphalt concrete (AC). We compared the exposure over one workday in 16 road pavers participating in a survey at four paving sites, using mixes of conventional asphalt (SMA, AC) or mixes containing waste material (SMA-WPT, AC-WPT). The concentrations of 11 aldehydes in air were 515 and 902 microg m(-3) at the SMA-WPT and AC-WPT worksites, being 3 and 13 times greater than at the corresponding worksites laying conventional asphalt. Resin acids (2-42 microg m(-3)), which are known sensitizers, were detected only during laying of AC-WPT. The emission levels (microg m(-3)) of total particulates (300-500), bitumen fumes (60-160), bitumen vapour (80-1120), naphthalene (0.59-1.2), phenanthrene (0.21-0.32), pyrene (<0.015-0.20), benzo(a)pyrene (<0.01) and the sum of 16 PAHs (polycyclic aromatic hydrocarbons, 1.28-2.00) were similar for conventional and WPT asphalts. The dermal deposition of 16 PAHs on exposure pads (on workers' wrist) was low in all pavers (0.7-3.5 ng cm(-2)). Eight OH-PAH biomarkers of naphthalene, phenanthrene and pyrene exposures were quantified in pre- and post-shift urine specimens. The post-shift concentrations (mean +/- SD, micromol mol(-1) creatinine) of 1- plus 2-naphthol; 1-,2-,3-,4- plus 9-phenanthrol; and 1-hydroxypyrene were, respectively, for asphalt workers: 18.1+/- 8.0, 2.41 +/- 0.71 and 0.66+/- 0.58 (smokers); 6.0+/- 2.3, 1.70+/- 0.72 and 0.27+/- 0.15 (non-smokers); WPT asphalt workers: 22.0+/- 9.2, 2.82+/- 1.11 and 0.76+/- 0.18 (smokers); 6.8+/- 2.6, 2.35+/- 0.69 and 0.46+/- 0.13 (non-smokers). The work-related uptake of PAHs was low in all pavers, although it was significantly greater in smokers than in non-smokers. The WPT asphalt workers complained of eye irritation and sore throat more than the pavers who had a much lower exposure to aldehydes and resin acids.

  3. Fatigue behavior of asphalt mixtures colombian with addition recycled pavement asphalt to 100 %

    Directory of Open Access Journals (Sweden)

    Neidy Betssey Patiño Boyacá

    2015-01-01

    Full Text Available This research was conducted in order to establish the fatigue behavior of asphalt mixtures with gradations MD20 Instituto de Desarrollo Urbano (IDU and MDC 2 of The Instituto Nacional de Vías (INVIAS, with addition of recycled granular flexible pavement (RAP with asphalt of penetration 60/70 and 80/100. The first step was to characterize the asphalt and RAP as well as calculate the optimum percentage of asphalt to be added to 100 % RAP mixtures. Then samples were fabricated with different trapezoidal gradations and asphalt, to be tested finally fatigue at different deformations. Among the results found, it was determined that the tested mixtures have a high stiffness; although, it varies depending on the asphalt mix used and that the best fatigue life with respect to those studied is the MDC-2 with bitumen 80/100.

  4. Glazed Concrete

    DEFF Research Database (Denmark)

    Bache, Anja Margrethe

    2010-01-01

    Why glazed concrete? Concrete hardens and finds its strength at room temperature whereas clay products must first be fired before they achieve this strength. They are stronger and three times as durable as clay products, which is a weighty reason for choosing concrete.5 Another reason, which....... If this succeeds, it will be possible to manufacture thin, large-scale glazed concrete panels comparable in size to concrete sandwich construction and larger which, with or without back-casting, can work as load-bearing construction elements....

  5. Behaviour of asphalt rubber mixtures with different crumb rubber and asphalt binder sources

    OpenAIRE

    Fontes, Liseane P. T. L.; Pereira, Paulo A. A.; Pais, Jorge C.; Trichês, Glicério

    2006-01-01

    This study evaluates the performance in laboratory of gap graded mixture prepared with different crumb rubber types and different conventional grade asphalt binders. The asphalt rubbers were prepared via wet process (continuous blend) and their properties were measured through the current tests: (i) penetration;(ii) softening point: (iii) resilience; (iv) apparent viscosity using a Brookfield viscometer. The rheological properties for conventional asphalts were measured too, in order to evalu...

  6. Physical properties of asphalt rubber after being mixed with reclaimed asphalt mixes

    OpenAIRE

    Pais, Jorge C.; Pereira, Paulo A. A.; Junior, J.; Gardete, Dinis

    2008-01-01

    Recycling of road pavements became an effective technique after the European legislation defined the amount of reclaimed material that could be sent to landfills. This rehabilitation technique allows the re-use of old pavement material and favours the reduction of the amount of new materials used to produce new pavement layers. One of the most promising pavement rehabilitation techniques uses asphalt rubber mixtures, i.e. asphalt mixtures in which the binder is asphalt modified by crumb r...

  7. Investigating In Situ Properties of Recycled Asphalt Pavement with Foamed Asphalt as Base Stabilizer

    OpenAIRE

    Antonis Kaltsounis; Vasilis Papavasiliou; Andreas Loizos; Christina Plati

    2010-01-01

    The objective of the present study was to conduct a comprehensive field experiment for the in situ assessment of in-depth recycled asphalt pavement using foamed asphalt as a stabilization treatment for base works. For this purpose Nondestructive Testing (NDT) data collected using the Falling Weight Deflectometer (FWD) and Ground Penetrating Radar (GPR) along a foamed asphalt recycled pavement section was thoroughly analysed. Critical issues including the stabilized material curing and the con...

  8. Using Pyrolized Carbon Black (PCB) from Waste Tires in Asphalt Pavement (Part 2, Asphalt Binder)

    OpenAIRE

    Zeng, Yongdong; Lovell, C. W.

    1996-01-01

    Scrap tires derived from automobiles have become a large environmental problem in the United States. In this study, research is carried out to investigate the potential use of tire-derived pyrolyzed carbon black from scrap tires as an asphalt cement modifier. The asphalt cements used in this research were AC10 and AC20. Penetration and softening point tests were performed to obtain the consistency of the asphalt cements. The pyrolyzed carbon black, as provided by Wolf Industries, was comb...

  9. Concrete Hinges

    DEFF Research Database (Denmark)

    Halding, Philip Skov; Hertz, Kristian Dahl; Schmidt, Jacob Wittrup

    2014-01-01

    In the first part of the 20th century concrete hinges developed by Freyssinet and Mesnager were widely tested and implemented in concrete structures. The concrete hinges were used a great deal in closed-spandrel arch bridges. Since such a bridge type has not been competitive for the past 40 years......, the research in concrete hinges has not evolved significantly in that period. But introducing a new state-of-the-art concrete arch bridge solution (Pearl-Chain arches invented at the Technical University of Denmark) creates a necessity of a concrete hinge research based on modern standards. Back when research...... in concrete hinges was more common different designs were proposed for the geometry and reinforcement. Previous research focused on fatigue, multi-axial stresses around the hinge throat, and the relation between rotation- and moment. But many different test-setups were proposed by different researchers...

  10. Change in fatigue behavior of asphalt hot mixes produced with asphalt rubber binders

    OpenAIRE

    Neto, Silvrano Adonias Dantas; Farias, Farias, Márcio Muniz de; Pais, Jorge C.

    2009-01-01

    Fatigue life of asphalt hot mixes is given as a function of both stiffness and tensilestrains induced in the bottom of the wearing courses of flexible pavements. In conventional as-phalt hot mixes the increase of stiffness leads to a decrease of fatigue life. However, this work shows that there is an increase of both fatigue life and stiffness of asphalt rubber hot mixes in comparison with the asphalt hot mixes produced with straight binders. In this work laboratory tests were performed in as...

  11. The Use of Steel Works Crushed Slag (Lidonit in the Preparation of Asphalt Mixtures

    Directory of Open Access Journals (Sweden)

    Gh. Gugiuman

    2004-01-01

    Full Text Available The high costs of the quarry crushed aggregates (producer costs to which additional railroad transport costs are taken into account result in the fact that at large distance away from quarry lesser amounts of chippings and crushing sands are provided only. The initiation of the crushed aggregates production manufactured out of steelworks crushed slag. Lidonit, at a competitive delivering price, has led to the first series of laboratory tests. In the first stage two asphalt concrete mixtures were made in cube-shaped and cylinder-shaped (Marshall test-tubes on which physical and mechanical characteristic values are determined. The results of these first tests outlined the real opportunity of using these products in supplying the roads and streets with asphalt mix for pavements.

  12. Method of reprocessing radioactive asphalt solidification products

    International Nuclear Information System (INIS)

    Purpose: To obtain heat-stable solidification products and decrease the total volume thereof by modifying the solidified form by the reprocessing of existent radioactive asphalt solidification products. Method: Radioactive asphalt solidification products are heated into a fluidized state. Then, incombustible solvents such as perchloroethylene or trichloroethylene are added to a dissolving tank to gradually dissolve the radioactive asphalt solidification products. Thus, organic materials such as asphalts are transferred into the solvent layer, while inorganic materials containing radioactive materials remain as they are in the separation tank. Then, the inorganic materials containing the radioactive materials are taken out and then solidified, for example, by converting them into a rock or glass form. (Kawakami, Y.)

  13. Performance Characteristics of Silane Silica Modified Asphalt

    OpenAIRE

    Xuedong Guo; Mingzhi Sun; Wenting Dai; Shuang Chen

    2016-01-01

    At present there are many kinds of fillers and modifier used for modified asphalt, but the effect of modifier differs in thousands of ways; most of them can increase the high temperature performance of asphalt, but the modified effect of low-temperature crack resistance, water stability, and antifatigue performance is different. Aiming at the subsistent problems, this paper innovatively puts forward the idea of taking the silane silica (nanosilica modified with silane coupling agent) as fille...

  14. Safety evaluation of asphalt products, (1)

    International Nuclear Information System (INIS)

    The safety of activity-containing asphalt products kept in enclosed storage was evaluated from considerations of radiolysis and hydrogen evolution. The samples examined were mainly homogeneous asphalt products containing 43w/0 of sludge produced in routine operation of the asphalt plant at the Japan Atomic Energy Research Institute (JAERI), the samples were irradiated with external 60Co γ-ray source to a dose of 109 R. The bulk of the gases evolving from the asphalt product is hydrogen, which constitutes 75 -- 95% of the total gas evolution. The total amount of gases generated during infinite time is proportional to the total exposure dose; hydrogen evolves at a rate of 5.5x10-3 cm3/g.MR. The amount of total gas evolution is governed solely by the quantity of asphalt, and is independent of the sludge contained therein. Nor do differences in the rate of dose appear to have any significant effect. In so far as concerns smallness of radiolysis, slightly better performance can be expected from straight than from blown asphalt. There is no danger of explosion of the asphalt products currently generated at JAERI (10-5 Ci/kg), which can be expected to accumulate in infinite time no more than about 3 cm3 from a 200 l product. Only asphalt products containing activity in concentrations exceeding 10-1 Ci/kg risk explosion when kept in enclosed storage, through accumulation of hydrogen in quantity exceeding the explosion limit in a relatively short time. (auth.)

  15. Asphalt mixtures produced with 100% reclaimed materials

    OpenAIRE

    Oliveira, Joel; Silva, Hugo Manuel Ribeiro Dias da; Jesus, Carlos M. G.

    2011-01-01

    The environmental and economic benefits of using Reclaimed Asphalt Pavement (RAP) material in hot mix asphalt (HMA) applications could be pushed up to the limit, by producing totally recycled HMAs (100% RAP), but the performance of this alternative must be satisfactory. In fact, these mixtures could possibly present a lower performance due to the behaviour of the aged binder, which loses its lighter fractions with time. In order to improve the mixture properties, a binder rejuvenator should b...

  16. Rapid determination of actinides in asphalt samples

    International Nuclear Information System (INIS)

    A new rapid method for the determination of actinides in asphalt samples has been developed that can be used in emergency response situations or for routine analysis. If a radiological dispersive device, improvised nuclear device or a nuclear accident such as the accident at the Fukushima Nuclear Power Plant in March, 2011 occurs, there will be an urgent need for rapid analyses of many different environmental matrices, including asphalt materials, to support dose mitigation and environmental clean-up. The new method for the determination of actinides in asphalt utilizes a rapid furnace step to destroy bitumen and organics present in the asphalt and sodium hydroxide fusion to digest the remaining sample. Sample preconcentration steps are used to collect the actinides and a new stacked TRU Resin + DGA Resin column method is employed to separate the actinide isotopes in the asphalt samples. The TRU Resin plus DGA Resin separation approach, which allows sequential separation of plutonium, uranium, americium and curium isotopes in asphalt samples, can be applied to soil samples as well. (author)

  17. Rheological properties of asphalts with particulate additives

    Energy Technology Data Exchange (ETDEWEB)

    Shashidhar, N. [EBA Engineering, Baltimore, MD (United States); Chollar, B.H. [Federal Highway Administration, McLean, VA (United States)

    1996-12-31

    The Superpave asphalt binder specifications are performance-based specifications for purchasing asphalt binders for the construction of roads. This means that the asphalt is characterized by fundamental material (rheological) properties that relate to the distress modes of the pavements. The distress modes addressed are primarily rutting, fatigue cracking and low temperature cracking. For example, G*/sin({delta}) is designed to predict the rutting potential of pavements, where G* is the magnitude of the complex shear modulus and 6 is the phase angle. The binder for a road that is situated in a certain climatic zone requires the binder to have a minimum G*/sin({delta}) of 2200 Pa at the highest consecutive 7-day average pavement temperature the road had experienced. Implicit in such a performance based specification is that the fundamental property, G*/sin({delta}), of the binder correlates with rutting potential of the pavement regardless of the nature of the binder. In other words, the specification is transparent to the fact that the binder can simply be an asphalt, or an asphalt modified by polymers, particulates and other materials that can form a two-phase mixture. This paper discusses the asphalt-particulate system.

  18. Study on Producing Heavy Paving Asphalt

    Institute of Scientific and Technical Information of China (English)

    Liu Daosheng; Gao Zhirong; Huo Kaifu; Liao Kejian

    2002-01-01

    The highly viscous crude oil from Shuguang No. 1 zone of Liaohe oilfield features high density,high viscosity and low wax content. It contains no gasoline fraction and its diesel oil fraction yield is only 7.19%, which belongs to the low sulfur naphthenic stocks crude oil. Its heavy fraction is not suited for producing lubricating oil. Its heavy oil, which contains more resins and asphaltenes and less wax, is not an ideal feedstock for catalytic cracking, but is the ideal raw material for producing high-grade paving asphalt.Now this highly viscous crude oil is used as fuel oil after being emulsified in Liaohe oilfield, but its viscosity is so high that it cannot be atomized uniformly and burned completely, resulting not only in waste of oil resource but also in reduction of economical benefit. To make full use of this oil resource and alleviate the shortfall of high grade paving asphalt in China, various brands of asphalt meeting Q/SHR003-1998and ESSO specifications were developed by blending vacuum residue of the said oil and a blending component which are rich in aromatics and deficient in wax. The impact of blending component on properties of blended asphalt has been investigated and road performances of these blended asphalts were studied. The laboratory test results show that the blended asphalts have good road performance and antiaging property.

  19. Asphalt wear and pollution transport

    Energy Technology Data Exchange (ETDEWEB)

    Lindgren, Asa [Division of Traffic Engineering, Lulea University of Technology Lulea (Sweden)

    1996-09-06

    Studded tires cause extensive wear of road surfaces during winter producing small particles. Besides transporting different adsorbed pollutants these particles also discharge metal ions by their own natural content. The major part (95%) of the asphalt is composed of stone fractions. The rest consists mainly of bitumen, which contains trace quantities of metals. Laboratory studies in this study have demonstrated different adsorbing properties of metal ions, as well as differences in adsorption when comparing stone materials. Two stone materials, a gabbro and a porphyry, have been tested for their adsorption properties concerning Pb, Cu, Zn and Cd. The gabbro showed better adsorption capacity than the porphyry. Gabbro has coarser grains, it is softer, and also has a higher content of most metals compared to the porphyry. In all tests lead and copper are more adsorbed than zinc and cadmium. All metal ions are released at about the same pH ({approx}4)

  20. Effects of reclaimed asphalt pavement on indirect tensile strength test of conditioned foamed asphalt mix

    International Nuclear Information System (INIS)

    This paper presents the results of Indirect Tensile Strength (ITS) Test for samples prepared with reclaimed asphalt pavement (RAP). Samples were conditioned in water at 25°C for 24 hours prior to testing. Results show that recycled aggregate from reclaimed asphalt pavement performs as well as virgin aggregate.

  1. Effects of reclaimed asphalt pavement on indirect tensile strength test of conditioned foamed asphalt mix

    Science.gov (United States)

    Yati Katman, Herda; Rasdan Ibrahim, Mohd; Yazip Matori, Mohd; Norhisham, Shuhairy; Ismail, Norlela

    2013-06-01

    This paper presents the results of Indirect Tensile Strength (ITS) Test for samples prepared with reclaimed asphalt pavement (RAP). Samples were conditioned in water at 25°C for 24 hours prior to testing. Results show that recycled aggregate from reclaimed asphalt pavement performs as well as virgin aggregate.

  2. 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

  3. Asphalte

    OpenAIRE

    Foley, S.

    1987-01-01

    The Burnett Archive of Working Class Autobiographies was gathered together by John Burnett, David Vincent and David Mayall whilst compiling their three volumes annotated bibliography, "The Autobiography of the Working Class" (Harvester Press, 1984-1989). This book includes descriptions of unpublished autobiographies and indicates their locations. Excerpts from some of the autobiographies have been published in "Destiny obscure: autobiographies of childhood, education, and family from the1820s...

  4. Development of an Image-based Multi-Scale Finite Element Approach to Predict Fatigue Damage in Asphalt Mixtures

    Science.gov (United States)

    Arshadi, Amir

    compared. Indirect tensile fatigue tests were conducted on asphalt mixture samples. A comparison between experimental results and the results from simulation shows that the model developed in this study is capable of predicting the effect of asphalt binder properties and aggregate micro-structure on mechanical behavior of asphalt concrete under loading.

  5. Experimental studies of biodegradation of asphalt by microorganisms

    International Nuclear Information System (INIS)

    On the geological disposal system of the radioactive wastes, the activities of the microorganisms that could degrade the asphalt might be significant for the assessment of the system performance. As the main effects of the biodegradation of the asphalt, the fluctuation of leaching behavior of the nuclides included in asphalt waste has been indicated. In this study, the asphalt biodegradation test was carried out. The microorganism of which asphalt degradation ability was comparatively higher under aerobic condition and anaerobic condition was used. The asphalt biodegradation rate was calculated and it was evaluated whether the asphalt biodegradation in this system could occur. The results show that the asphalt biodegradation rate under anaerobic and high alkali condition will be 300 times lower than under aerobic and neutral pH. (author)

  6. EMISSION REDUCTION OF HYDROGEN SULFIDE AND SULFUR DIOXIDE FROM ASPHALT BINDER CONTAINING SULFUR / СНИЖЕНИЕ ЭМИССИИ СЕРОВОДОРОДА И ДИОКСИДА СЕРЫ ИЗ СЕРОБИТУМНЫХ МАТЕРИАЛОВ

    OpenAIRE

    Gladkikh V. A. / Гладких Виталий Александрович; Korolev E. V. / Королев Евгений Валерьевич

    2014-01-01

    The authors provide the model of possible processes in sulfur asphalt concrete mixture. Based on the analysis of the results of laboratory studies the authors establish the impact of major prescription and technological factors on the emission of toxic gases and formulate technical specifications for the components and mode of production of sulfur asphalt concrete mixtures. The method for determining the emission of toxic gases, allowing determination of the quantities of products released fr...

  7. Theoretic computing model of combustion process of asphalt smoke

    Institute of Scientific and Technical Information of China (English)

    HUANG Rui; CHAI Li-yuan; HE De-wen; PENG Bing; WANG Yun-yan

    2005-01-01

    Based on the data and methods provided by research literature, dispersing mathematical model of combustion process of asphalt smoke is set by theoretic analysis. Through computer programming, the dynamic combustion process of asphalt smoke is calculated to simulate an experimental model. The computing result shows that the temperature and the concentration of asphalt smoke influence its burning temperature in approximatively linear manner. The consumed quantity of fuel to ignite the asphalt smoke needs to be measured from the two factors.

  8. Effects of preparation process on performance of rubber modified asphalt

    Science.gov (United States)

    Liu, Hanbing; Luo, Guobao; Wang, Xianqiang; Jiao, Yubo

    2015-06-01

    The rational utilization of waste rubber tire is essential for the environmental protection. Utilizing rubber particles to modify asphalt can not only improve asphalt performance, but also help the recycling of waste materials. Considering the effect of different preparation process parameters on the performance of rubber modified asphalt, this paper analyzes the effects of the shear temperature, shear time and shear rate on the performance of rubber modified asphalt, and provided a reference for its preparation.

  9. Reinforcing Effects of Carbon Black on Asphalt Binder for Pavement

    OpenAIRE

    Yamaguchi, Katsuyuki; Sasaki, Iwao; Nishizaki, Itaru; Meiarashi, Seishi; Moriyoshi, Akihiro

    2005-01-01

    Carbon black, used as a reinforcing filler for rubber materials, was evaluated for asphalt binders in pavements. Carbon black added to straight asphalt within 20 wt% caused an increase in the elastic modulus and a decrease in the viscosity of the asphalt, especially at temperatures higher than room temperature. Addition of carbon black raised the maximum service temperature of asphalt in the category of the binder performance grade according to the SHRP (Strategic Highway Research Program) sp...

  10. Influence of crumb rubber gradation on asphalt-rubber properties

    OpenAIRE

    Neto, Silvrano Adonias Dantas; Farias, Márcio Muniz de; Pais, Jorge C.; Pereira, Paulo A. A.

    2006-01-01

    Asphalt rubber is a material produced by the incorporation of crumb rubber obtained from ground tires in straight asphalt and its properties are influenced by the components properties. The crumb rubber gradation is one of the variables which have a significant influence on asphalt rubber properties. Thus, this work studies the influence of crumb rubber gradation on the asphalt rubber properties expressed by penetration, rotational viscosity (using the Brookfield viscometer), r...

  11. Biodegradation of Asphalt Cement-20 by Aerobic Bacteria

    OpenAIRE

    Pendrys, John P.

    1989-01-01

    Seven gram-negative, aerobic bacteria were isolated from a mixed culture enriched for asphalt-degrading bacteria. The predominant genera of these isolates were Pseudomonas, Acinetobacter, Alcaligenes, Flavimonas, and Flavobacterium. The mixed culture preferentially degraded the saturate and naphthene aromatic fractions of asphalt cement-20. A residue remained on the surface which was resistant to biodegradation and protected the underlying asphalt from biodegradation. The most potent asphalt-...

  12. Modification of Asphalt by the Use of Crumb Rubber

    OpenAIRE

    Shah Room; Muhammad Aleem; Muhammad Ahmad Rana; Umair Anwar Awan; Sajjad Ali

    2014-01-01

    Health aspects enforced to ponder a study on asphalt which incorporate rubber crumbs to increase strength and flexibility of asphalt. Disposal of waste tires is a menace and it’s a serious problem globally because it is not easily biodegradable as these tires consume large spaces, open burning cause serious problems. By the use of rubber tires, this scrap is utilized efficiently and reduces the cost of asphalt to produce economical system. The asphalt is absorbed by the rubber par...

  13. Full-Depth Asphalt Pavements for Parking Lots and Driveways.

    Science.gov (United States)

    Asphalt Inst., College Park, MD.

    The latest information for designing full-depth asphalt pavements for parking lots and driveways is covered in relationship to the continued increase in vehicle registration. It is based on The Asphalt Institute's Thickness Design Manual, Series No. 1 (MS-1), Seventh Edition, which covers all aspects of asphalt pavement thickness design in detail,…

  14. 40 CFR 52.2054 - Control of asphalt paving material.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Control of asphalt paving material. 52... asphalt paving material. (a) Notwithstanding any provisions to the contrary in the Pennsylvania Implementation Plan, the Pennsylvania Department of Transportation shall restrict the annual usage of asphalts...

  15. Influence of mixed recycled aggregate on the physical e mechanical properties of recycled concrete

    OpenAIRE

    Medina Martínez, César; Zhu, Wenzhong; Howind, Torsten; Sánchez de Rojas, María Isabel; Frías Rojas, Moisés

    2014-01-01

    This article discusses the findings of a feasibility study on the partial replacement of natural coarse aggregate with a poor quality recycled aggregate from construction and demolition waste in the manufacture of concrete of 30 MPa strength grade. The mixed recycled aggregate used had a high asphalt and floating material content. Workability, density, compressive and tensile strength, water absorption and sorptivity were studied in a series of concretes containing 25 or 50% of th...

  16. Design and Performance of Hot Mix Asphalts with High Percentages of Reclaimed Asphalt: Approach followed in the Paramix Project

    OpenAIRE

    Pérez, F; Rodriguez, M.; De Visscher, J.; Vanelstraete, A.; Bock, L.

    2004-01-01

    The use of reclaimed asphalt pavement (RA) in new asphalt pavements can provide important economical savings, while reducing the negative environmental impact. The European research project PARAMIX aims to improve the techniques for hot mix recycling in plant and cold mix in situ recycling, so as to increase the amount of reclaimed asphalt and develop competitive road pavement rehabilitation techniques. This paper deals with the design of hot mix asphalts for the project. The di...

  17. 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

  18. Concrete products

    Energy Technology Data Exchange (ETDEWEB)

    Anon

    2002-01-01

    Increased strength and durability in concrete products can be achieved through the addition of fly ash during the manufacturing process. The properties of concrete are enhanced by fly ash. The benefits include cost and the environment. Fly ash is normally defined as finely divided residue resulting from the combustion of pulverized coal, carried from the combustion chamber to the furnace by exhaust gas. The main applications of fly ash in concrete products are ready mix concrete, bridge decks and support footing, precast structures, blocks and bricks, and pipes. The Canadian Standards Association (CSA) has published standards to ensure that the desired physical properties of the concrete are achieved and the standards are found in CSA A23.1, detailing the engineering materials and mix proportions. The type of fly ash to be used for specific properties is important. Finishing and curing operations must be performed with care. The free lime generated by cement hydration reacts with fly ash, forming additional calcium silicate hydrate. Permeability of the concrete is reduced since the calcium silicate hydrate fills the void resulting from the cement pour. Some of the benefits to be derived from fly ash in concrete are: water reduction, improved workability, high ultimate strength, improved pumpability, and reduced heat of hydration. In addition, the life cycle costs are lower, and great strength is obtained. An environmental benefit results from the reduction of natural resource consumption.

  19. Current practices for modification of paving asphalts

    Energy Technology Data Exchange (ETDEWEB)

    Bahia, H.U.; Perdomo, D. [Asphalt Institute, Lexington, KY (United States)

    1996-12-31

    The Superpave binder specification, AASHTO MP1, has introduced new concepts for selecting paving asphalt binders. The specification, in addition to using rheological and failure measurements that are more related to performance, is based on the idea that the criteria to maintain a satisfactory contribution of asphalt binders to the resistance of pavement failures remains the same but have to be satisfied at critical application temperatures. The test procedures require that the material be characterized within certain ranges of strains or stresses to ensure that material and geometric non-linearities are not confounded in the measurements. These new specification concepts have resulted in re-evaluation of asphalt modification by the majority of modified asphalt suppliers. The philosophy of asphalt modification is expected to change, following these new concepts, from a general improvement of quality to more focus on using modifiers based on the most critical need as defined by two factors: (1) The application temperature domain and (2) the type of distress to be remedied. The new specification requirements should result in a more effective use of modifiers as the amount and type of modifier will be directly related to the application environment and the engineering requirements.

  20. Ethanol based foamed asphalt as potential alternative for low emission asphalt technology

    Directory of Open Access Journals (Sweden)

    Mohd Rosli Mohd Hasan

    2016-04-01

    Full Text Available Foamed asphalt typically relies on water as a foaming agent because water becomes gaseous at elevated temperatures, generating numerous tiny bubbles in the asphalt and causing spontaneous foaming. In this study, ethanol was used as a potential alternative to water as a foaming agent. Ethanol is expected to be a physical blowing agent in the same manner as water, except it requires less energy to foam due to its 78 °C boiling point. This study compares the performance of water and ethanol as foaming agents through the measurements of rotational viscosity, the reduction in temperature during foaming, and volatile loss. The ethanol-foamed asphalt binders were prepared at 80 °C and 100 °C, while the water-foamed asphalt binders were prepared at 100 °C and 120 °C. Additionally, the rolling thin film oven (RTFO was used to generate short-term aging of the foamed asphalt binders. A rotational viscometer was used to determine the viscosity of the asphalt binders at 80 °C, 100 °C, 120 °C, 140 °C, and 160 °C. Overall, ethanol can function in the same manner as water but requires less energy to foam. It is proven based on the smaller drop in temperature of the asphalt binder foamed using ethanol compared with that prepared with water. This is due to the lower latent heat capacity of ethanol, which requires less energy to vaporize compared with water. Through the rotational viscometer test, ethanol performs better in lowering the viscosity of asphalt binders, which is essential in allowing production processes at low temperatures, as well as a better workability and aggregate coating. Ethanol can be expelled from the foamed asphalt binders at a higher rate due to its lower boiling point and latent heat.

  1. Effects of Asphalt Mix Design Properties on Pavement Performance: A Mechanistic Approach

    Directory of Open Access Journals (Sweden)

    Ahmad M. Abu Abdo

    2016-01-01

    Full Text Available The main objective of this study was to investigate the effects of hot mix asphalt material properties on the performance of flexible pavements via mechanistic approach. 3D Move Analysis software was utilized to determine rutting and cracking distresses in an asphalt concrete (AC layer. Fourteen different Superpave mixes were evaluated by utilizing results of the Dynamic Modulus (|E⁎| Test and the Dynamic Shear Modulus (|G⁎| Test. Results showed that with the increase of binder content, the tendency of rutting in AC layer increased. However, with the increase of binder content, the cracking of AC layer lessened. Furthermore, when different binder grades were evaluated, results showed that with the increase of the upper binder grade number, rutting decreased, and with the increase of the lower binder grade number, rutting increased. Furthermore, analysis showed that with the increase of the lower binder grade number, higher percent of bottom up cracks would result. As a result of the analysis, binder grade should not be solely considered for cracking in AC layer; binder content and aggregate structure play a big role. Finally, results illustrated that the mechanistic approach is a better tool to determine the performance of asphalt pavement than commonly used methods.

  2. An Optimization Model for Design of Asphalt Pavements Based on IHAP Code Number 234

    Directory of Open Access Journals (Sweden)

    Ali Reza Ghanizadeh

    2016-01-01

    Full Text Available Pavement construction is one of the most costly parts of transportation infrastructures. Incommensurate design and construction of pavements, in addition to the loss of the initial investment, would impose indirect costs to the road users and reduce road safety. This paper aims to propose an optimization model to determine the optimal configuration as well as the optimum thickness of different pavement layers based on the Iran Highway Asphalt Paving Code Number 234 (IHAP Code 234. After developing the optimization model, the optimum thickness of pavement layers for secondary rural roads, major rural roads, and freeways was determined based on the recommended prices in “Basic Price List for Road, Runway and Railway” of Iran in 2015 and several charts were developed to determine the optimum thickness of pavement layers including asphalt concrete, granular base, and granular subbase with respect to road classification, design traffic, and resilient modulus of subgrade. Design charts confirm that in the current situation (material prices in 2015, application of asphalt treated layer in pavement structure is not cost effective. Also it was shown that, with increasing the strength of subgrade soil, the subbase layer may be removed from the optimum structure of pavement.

  3. 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. PMID:25695096

  4. 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.

  5. 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.

  6. Research on Alkaline Filler Flame-Retarded Asphalt Pavement

    Institute of Scientific and Technical Information of China (English)

    HU Shuguang; ZHANG Houji; WANG Jiaolan

    2006-01-01

    Used as flame retardant of tunnel asphalt pavement, organic bromides produce a large amount of poisons and smoke in construction and flame retardation stage. The alkaline filler was found to replace mineral filler, and the flame-retarded asphalt mixtures were produced. Experimental results show that these asphalt mixtures are smoke restrained; the performances and construction technology of asphalt pavement are not influenced; also the alkaline filler is of low-price. So this kind of flame-retarded asphalt mixtures is suitable for tunnel pavement.

  7. Pitch-asphalts - new binder for road construction

    Energy Technology Data Exchange (ETDEWEB)

    Stompel, Z.; Collin, G.; Szen, A.; Herion, G.

    1988-01-01

    Discusses chemical and physical properties of a mixture of pitches and asphalts produced by the Blachownia Chemical Plant. The mixture consists of coal tar pitches with 25.7% content of toluene-insoluble fractions, anthracene oil and Dex asphalt. The following properties were analyzed: density, softening and softening point, adhesion, viscosity, sedimentation after 14 days. Physical and chemical properties of the pitch-asphalt from Blachownia were compared to those of pitch-asphalt from Ruetgerswerke AG in the FRG. Pitch-asphalt properties were evaluated from the point of view of their use in road construction. 8 refs.

  8. Simulation of rheological behavior of asphalt mixture with lattice model

    Institute of Scientific and Technical Information of China (English)

    杨圣枫; 杨新华; 陈传尧

    2008-01-01

    A three-dimensional(3D) lattice model for predicting the rheological behavior of asphalt mixtures was presented.In this model asphalt mixtures were described as a two-phase composite material consisting of asphalt sand and coarse aggregates distributed randomly.Asphalt sand was regarded as a viscoelastic material and aggregates as an elastic material.The rheological response of asphalt mixture subjected to different constant stresses was simulated.The calibrated overall creep strain shows a good approximation to experimental results.

  9. Application of retardation time spectra of asphalt

    Institute of Scientific and Technical Information of China (English)

    ZHAN Xiao-li; ZHANG Xiao-ning; LU Liang

    2008-01-01

    To improve the performance of asphah pavement,the dynamic and static tests of asphalt were used to measure its viscoelastic properties under different time.Based on the obtained data of static creep compliances and dynamic compliances according to the static creep test and dynamic test of asphalt using the dynamic shear rheometer,the discrete retardation time spectra were attained using the non-linear regression method.All viseoelastic functions are mathematically equivalent and belong to the same retardation time spectra,so the dynamic compliances of asphalt were converted to the static creep compliance using the retardation time spectra.Good correlations were found betwin calculation results and measurement results.In accordalice to these findings,the retardation time spectra can accurately transform static and dynamic viscoelastic functions.Therefore,we can obtain viscoelastic properties over much larger time or frequency region than measurement results.

  10. Photocatalyticpaving concrete

    Directory of Open Access Journals (Sweden)

    Lyapidevskaya Ol'ga Borisovna

    2014-02-01

    Full Text Available Today bituminous concrete is a conventional paving material. Among its advantages one can name dustlessness and noiselessness, fine wear (up to 1 mm a year and fine maintainability. As the main disadvantages of this material one can name high slipperiness under humidification, low durability and weather resistance. Besides that, during placement of the bituminous concrete a lot of different air pollutants are emitted, which are harmful for environment and human’s health (they are listed in the paper according to the US Environmental Protection Agency materials. As an alternative, one can use cement-concrete pavement, which is in many ways more efficient than the bituminous concrete. It is proposed to enhance environmental performance of the cement-concrete pavement via usage of photocatalysis. The mechanism of different photocatalytic reactions is described in the paper, namely heterogeneous and homogeneous photocatalysis, photo-induces, photoactivated catalysis and catalytical photoreactions. It is pro-posed to use heterogeneous photocatalysis with titanium dioxide as a photocatalyst. The mechanism of photo oxidation of air contaminants, with the usage of titanium dioxide is2described. The paper sets problems, connected with the sensibilization of TiOto thevisible light (it is proposed to use titanium dioxide, doped with the atoms of certain elements to increase its sensibility to the visible light and with the development of a new photocatalytic paving concrete, which will meet the requirements, specified for paving in the climatic and traffic conditions of the Russian Federation.

  11. Asphalt rubber mixtures in Portugal: fatigue resistance

    OpenAIRE

    Miranda, Henrique; Batista, Fátima; Neves, José; Antunes, Maria de Lurdes; Fonseca, Paulo

    2009-01-01

    This paper presents a study concerning the fatigue behaviour of asphalt mixtures with bitumen modified with high content of crumb rubber used in Portugal. For assessing the fatigue behaviour of this type of mixtures, four asphalt mixtures with high content of crumb rubber were used: two field bituminous mixtures – an open-graded and a gap-graded – both with granite aggregates; and two laboratory manufactured bituminous mixtures – an open-graded mixture with granite aggregates and a gap-graded...

  12. Utilization of Electronic Waste Plastic in Concrete

    Directory of Open Access Journals (Sweden)

    Vivek S. Damal

    2015-04-01

    Full Text Available In India, bitumen pavements are commonly used for highways. Due to the increasing traffic intensity, distress such as rutting and cracking of pavements are very common in Indian roads. Under varying seasonal temperature, flexible pavements tend to become soft in summer and brittle in winter. Investigations revealed that properties of concrete can be better than bitumen roads. But now a day‟s concrete roads are used commonly because concrete roads have more life span than the bitumen roads. In large cities now a day‟s concrete roads are used because concrete roads are more durable, strengthen and having more life span than bitumen roads. Waste plastics and E-waste (electronic waste both by domestic and industrial sectors can be used in the production of asphalt mix. Waste plastic, mainly used for packing are made up of polyethylene, polypropylene, polystyrene. Electronic waste, abbreviated as e-waste, consists of discarded old computers, TVs, refrigerators; radios, etc are basically any electrical or electronic appliance that has reached its end of life. An experimental study is made on the utilization of E-waste particles as fine aggregates in concrete with a percentage replacement ranging from 0 % to 21.5% i.e. (7.5%, 15% and 21.5% on the strength criteria of M30 Concrete. Compressive strength Concrete with and without E- waste plastic as aggregates was observed which exhibits a good strength. The feasibility of utilizing E-waste plastic particles as partial replacement of fine aggregate has been presented. In the present study, compressive strength was investigated for Optimum Cement Content and 7.5% E-plastic content in mix yielded stability and very good in compressive strength of 43 grade cement.

  13. Investigating In Situ Properties of Recycled Asphalt Pavement with Foamed Asphalt as Base Stabilizer

    Directory of Open Access Journals (Sweden)

    Christina Plati

    2010-01-01

    Full Text Available The objective of the present study was to conduct a comprehensive field experiment for the in situ assessment of in-depth recycled asphalt pavement using foamed asphalt as a stabilization treatment for base works. For this purpose Nondestructive Testing (NDT data collected using the Falling Weight Deflectometer (FWD and Ground Penetrating Radar (GPR along a foamed asphalt recycled pavement section was thoroughly analysed. Critical issues including the stabilized material curing and the contribution of the asphalt layers to the structural properties of the in-depth recycled pavement are discussed. In addition, recommendations concerning the improvement of the structural condition of the in-depth recycled pavement are developed based on this practical approach of investigation using NDT.

  14. Study on the Durability of Steel Deck Pavement Asphalt Mixture Based on Rubber Powder and SBS Compound Modified Technology%基于橡胶粉与 SBS 复合改性技术钢桥面铺筑沥青混合料耐久性试验研究

    Institute of Scientific and Technical Information of China (English)

    魏斌

    2015-01-01

    In order to satisfy the bridge deck pavement of asphalt concrete special performance re-quirements of asphalt binder,Improve the flexibility of bridge deck pavement asphalt concrete,by adding different proportions of rubber powder and SBS modified asphalt and composite mix performance test anal-ysis,discusses the composite rubber powder modified asphalt mixture by Sophie toughened,shear,impact mechanism water stability,and recommended significantly modified asphalt concrete composite best over-all performance rubber particles content.%为了满足桥面铺装沥青混凝土对沥青结合料的特殊性能要求,提高桥面铺装沥青混凝土的柔韧性,通过对不同掺加比例的橡胶粉与 SBS 复合改性沥青及其混合料的性能进行试验分析,探讨了橡胶粉对复合改性沥青混合料的增柔增韧、抗剪、水稳定性的影响机理,并推荐了可以显著复合改性沥青混凝土综合使用性能的最佳橡胶颗粒掺量。

  15. 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.

  16. Microstructural Analysis and Rheological Modeling of Asphalt Mixtures Containing Recycled Asphalt Materials

    Directory of Open Access Journals (Sweden)

    Augusto Cannone Falchetto

    2014-09-01

    Full Text Available The use of recycled materials in pavement construction has seen, over the years, a significant increase closely associated with substantial economic and environmental benefits. During the past decades, many transportation agencies have evaluated the effect of adding Reclaimed Asphalt Pavement (RAP, and, more recently, Recycled Asphalt Shingles (RAS on the performance of asphalt pavement, while limits were proposed on the amount of recycled materials which can be used. In this paper, the effect of adding RAP and RAS on the microstructural and low temperature properties of asphalt mixtures is investigated using digital image processing (DIP and modeling of rheological data obtained with the Bending Beam Rheometer (BBR. Detailed information on the internal microstructure of asphalt mixtures is acquired based on digital images of small beam specimens and numerical estimations of spatial correlation functions. It is found that RAP increases the autocorrelation length (ACL of the spatial distribution of aggregates, asphalt mastic and air voids phases, while an opposite trend is observed when RAS is included. Analogical and semi empirical models are used to back-calculate binder creep stiffness from mixture experimental data. Differences between back-calculated results and experimental data suggest limited or partial blending between new and aged binder.

  17. Application of Cold Mix Asphalt in the Repair of Rural Roads%冷拌沥青在乡村公路修补中的应用

    Institute of Scientific and Technical Information of China (English)

    阳娟; 石月晴; 张子仪

    2016-01-01

    本文分析了目前农村公路的发展以及维护现状,指出水泥混凝土和热拌沥青混凝土在公路修补中的不足,进而提出冷拌沥青混凝土用于农村公路的想法。通过设计沥青混合料试件进行试验,选取混合料的和易性、稳定性、初始强度和抗水损失性进行了实验探究,验证了冷拌沥青混合料满足农村公路修补的要求,且具有高稳定性和低耗能等优点,最后总结出冷拌沥青在农村公路修补的市场和前景。%This paper analyzes the current development of rural roads and the maintenance of the status quo, points out the shortage of cement concrete and hot mix asphalt concrete in the road repair, and then puts forward the idea of cold mix asphalt concrete for the rural highway. Through the design of asphalt mixture test specimens, the workability, stability, initial strength and water resistance of the mixture are tested, the results show that cold asphalt mixture can meet the requirements of rural road repair, and have the advantages of high stability and low energy consumption etc. And finally it sums up the market and prospects of cold mix asphalt in the repair of the rural roads.

  18. The application research of new asphalt pavement structures in China%新型沥青路面结构在我国的应用研究

    Institute of Scientific and Technical Information of China (English)

    刘军霞

    2014-01-01

    This paper summarized and analyzed the existing problems of flexible base,composite base asphalt pavement structure in highway con-struction application,researched the technical measures to strengthen the new asphalt pavement structure performance,and discussed the low noise asphalt pavement,asphalt concrete cover surface technology,waterproof layer technology and other new technology,so as to enhance the use per-formance of asphalt pavement.%对柔性基层、组合式基层沥青路面结构在公路建设应用中存在的问题进行了总结分析,研究了加强新型沥青路面结构性能的技术措施,并对低噪声沥青路面、沥青混凝土罩面技术、防水层技术等新型技术作了论述,以不断提高沥青路面的使用性能。

  19. Asphalt modification with used lubricating oil

    Energy Technology Data Exchange (ETDEWEB)

    Villanueva, A.; Ho, S.; Zanzotto, L. [Calgary Univ., AB (Canada). Schulich School of Engineering, Bituminous Materials Research Laboratory

    2008-02-15

    A method of recycling waste lubricating oil from vehicles was presented. Various asphalt materials were modified with different amounts of lubricating oil and analyzed using standard Superpave tests. Dynamic shear rheometer (DSR) tests were then conducted to in order to obtain high temperature samples. Bending beam rheometer (BBR) and direct tension tests (DTT) were used to obtain low temperature sample profiles. Potential applications for the materials were reviewed. Environmental impacts and costs associated with using the materials were also presented. The study demonstrated that waste lubricating oil can be used as a softening agent in modified asphalt binders using a low temperature grade technique. It was concluded that the low cost of waste lubricating oil in Alberta makes it a potential resource for asphalt modification. The oil modified samples lowered the high-temperature grade and did not improve the overall quality of the asphalt. Further testing is needed to examine the quality and consistency of lubricating oils. 19 refs., 7 tabs., 12 figs.

  20. Microbial Life in a Liquid Asphalt Desert

    Science.gov (United States)

    Schulze-Makuch, Dirk; Haque, Shirin; de Sousa Antonio, Marina Resendes; Ali, Denzil; Hosein, Riad; Song, Young C.; Yang, Jinshu; Zaikova, Elena; Beckles, Denise M.; Guinan, Edward; Lehto, Harry J.; Hallam, Steven J.

    2011-04-01

    Pitch Lake in Trinidad and Tobago is a natural asphalt reservoir nourished by pitch seepage, a form of petroleum that consists of mostly asphaltines, from the surrounding oil-rich region. During upward seepage, pitch mixes with mud and gases under high pressure, and the lighter portion evaporates or is volatilized, which produces a liquid asphalt residue characterized by low water activity, recalcitrant carbon substrates, and noxious chemical compounds. An active microbial community of archaea and bacteria, many of them novel strains (particularly from the new Tar ARC groups), totaling a biomass of up to 107 cells per gram, was found to inhabit the liquid hydrocarbon matrix of Pitch Lake. Geochemical and molecular taxonomic approaches revealed diverse, novel, and deeply branching microbial lineages with the potential to mediate anaerobic hydrocarbon degradation processes in different parts of the asphalt column. In addition, we found markers for archaeal methane metabolism and specific gene sequences affiliated with facultative and obligate anaerobic sulfur- and nitrite-oxidizing bacteria. The microbial diversity at Pitch Lake was found to be unique when compared to microbial communities analyzed at other hydrocarbon-rich environments, which included Rancho Le Brea, a natural asphalt environment in California, USA, and an oil well and a mud volcano in Trinidad and Tobago, among other sites. These results open a window into the microbial ecology and biogeochemistry of recalcitrant hydrocarbon matrices and establish the site as a terrestrial analogue for modeling the biotic potential of hydrocarbon lakes such as those found on Saturn's largest moon Titan.

  1. Sulfur extended asphalt pavement evaluation: Executive summary

    Science.gov (United States)

    Mahoney, J. P.

    1982-09-01

    This summary report overviews two previously issued study reports. One report assesses The availability and pricing of sulfur with respect to sulfur extended asphalt (SEA) paving mixture is assessed. A laboratory oriented testing program which was principally used to examine the durability and aging characteristics of SEA paving mixtures is reported.

  2. 沥青混凝土的动水压力模拟试验%Simulation Test of Dynamic Water Pressure for Asphalt Pavement

    Institute of Scientific and Technical Information of China (English)

    姜旺恒; 张肖宁; 李智

    2011-01-01

    The simulation method of dynamic water pressure is one of the basic theories which should be researched to improve the water damage resistance of asphalt mixture. On the basis of designing the test system which generates dynamic water pressure in the voids of asphalt concrete by compressed air, the cylindrical asphalt concrete specimen, which has a space on its bottom and covered with epoxy resin glue on its lateral, was made to induct the water flow oriented through asphalt concrete voids to the established space, thus the oriented water erosion mode was formed. It is found by FEM that (1) the drainage could reduce the pore pressure in the specimen along its depth, which means pore pressure condition in voids of semi-rigid base asphalt pavement is harsher than that in drainage base asphalt pavement. It is found from the test by this specimen that ( 1 ) the splitting strength of the specimen decreased gradually due to water erosion; ( 2 ) powder escaped from asphalt concrete, shear failure occurred, and asphalt film stripped from the damaged surface during the oriented water erosion to the specimen at 60 ℃, which reveals that the effect of simulated dynamic pore pressure is significant; (3) asphalt mixture with void ratio about 8% has minimum resistance to water damage. These phenomena and test results reveal that the method is feasible for evaluating the water damage resistance of asphalt concrete.%动水压力模拟试验方法是提高沥青混合料抗水损害性能需要研究的基础理论问题之一.在设计以气压传递激发沥青混凝土孔隙中水压动态变化的试验装置的基础上,通过封闭圆柱形试件的侧壁和在试件底端构造蓄水空间以引导水在孔隙中向下渗流,形成定向冲刷模式.经有限元计算发现随试件深度增加水压减小,说明半刚性基层沥青路面比排水基层沥青路面承受的水压力条件更严酷.应用该试验装置发现动水冲刷使试件

  3. Historic Concrete: From Concrete Repair to Concrete Conservation

    NARCIS (Netherlands)

    Heinemann, H.A.

    2013-01-01

    Concrete like materials were already applied during the Roman Empire. After the decline of the Roman Empire, a wide scale application of concrete only reappeared in the 19th century. Here lies also the origin of modern (reinforced) concrete. Since then, both concrete application and composition have

  4. Concrete Memories

    DEFF Research Database (Denmark)

    Wiegand, Frauke Katharina

    2015-01-01

    and poetic appropriations and inscriptions of the bunker site are depicted. Ranging between overlooked side presences and an overwhelming visibility, the concrete remains of fascist war architecture are involved in and motivate different sensuous experiences and mnemonic appropriations. The article meets...

  5. 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.

  6. Viscoelastic Analysis of Asphalt Mixture Based on Creep Test

    Directory of Open Access Journals (Sweden)

    Lihua Zhao

    2013-01-01

    Full Text Available Two kinds of mineral fibers were added to AC-16C asphalt mixture. Trabecular bending creep experiments of asphalt mixtures were carried out at -10 and 20°C. The influence of mineral fibers on the low temperature viscoelasticity of asphalt mixtures were analyzed systemically. Furthermore, by using Origin, Burgers viscoelastic model was used to investigate the parameter regression for the creep test results at the different temperatures. The results show that the addition of mineral fibers can effectively improve the bending creep rate of asphalt mixtures, indicates the increase of crack resistance of asphalt mixtures. Good agreement between experimental data and Burgers model was found. The parameters of Burgers model at different temperatures can also provide data support for the viscoelastic design of asphalt pavements.

  7. Research on Surfactant Warm Mix Asphalt Construction Technology

    Science.gov (United States)

    Li, Guoliang; Sun, Jingxin; Guo, Xiufeng

    Discharging temperature of hot asphalt mixture is about 150°C-185°C, volatilization of asphalt fume harms people's health and fuel cost is high. Jinan Urban Construction Group applies PTL/01 asphalt warm mix agent to produce warm mix asphalt to construction of urban roads' asphalt bituminous pavement. After comparing it with performance of traditional hot asphalt mixture, mixing temperature may be reduced by 30°C-60°C, emission of poisonous gas is reduced, energy conservation and environmental protection are satisfied, construction quality reaches requirements of construction specifications and economic, social and environmental benefits are significant. Thus, it can be used for reference for green construction of urban roads.

  8. Determination of Rheological Properties of Bio Mastic Asphalt

    OpenAIRE

    R. Muniandy; H. Jafariahangari; Yunus, R.; S. Hassim

    2008-01-01

    Due to the high oil prices the price of asphalt binder has increased tremendously. This scenario has warranted demand for higher viscosity cheaper asphalt for pavement construction. A study was conducted to take advantage of the Empty Fruit Bunch (EFB) of Date and Oil Palm trees (which are considered as waste) to produce cellulose fiber to be used as additives in the asphalt binder. If these EFB's could be beneficially utilized in any application, it would reduce the load on the nation's land...

  9. Comparison between asphalt rubber and conventional mixtures in overlay design

    OpenAIRE

    Fontes, Liseane P. T. L.; Trichês, Glicério; Pereira, Paulo A. A.; Pais, Jorge C.

    2008-01-01

    Asphalt modified with crumb rubber has been used to produce asphalt rubber mixtures for pavement overlays subjected to heavy loads and high temperatures. Under severe conditions, these mixtures are capable of resisting permanent deformations, having an extended fatigue life and resisting crack propagation in comparison to conventional ones. A laboratory research was conducted to determine the performance properties of overlays with asphalt rubber mixtures produced through wet processes using ...

  10. Performance Evaluation of Semiplastic Recycled Cold Asphalt Using Noncement Binders

    OpenAIRE

    Lee, Byung Jae; Bang, Jin Wook; Kim, Jeong Su; Jang, Young Il

    2015-01-01

    The optimal mixing conditions for semiplastic recycled cold asphalt, which recycled waste asphalt and used noncement binders (NCB), were assessed through verification of the performance. The NCB of 6% desulfurization gypsum mixing was found to have the most outstanding properties. For the Marshall stability, 4% (NCB) filler mixing brought about a 1.92-time strength increase effect compared to OPC (2%) and was improved when using modified asphalt and SBR. The flow test results showed that alth...

  11. Extending the Life of Asphalt Longitudinal Paving Joints

    OpenAIRE

    Hedges, Rex; Brownridge, Jim

    2014-01-01

    Is premature asphalt joint failure bringing your PASER number down? Participants will learn how applying asphalt preservative seals directly to the asphalt longitudinal paving joint can restore plasticity and flexibility and how application of in-depth sealing methods will protect against harmful UV rays, prevent oxidation, and waterproof against chloride intrusion. Rehabilitation methods to repair poorly performing and failed paving joints will also be covered.

  12. Increasing the rate of recycled asphalt: an experimental study

    Directory of Open Access Journals (Sweden)

    Marjan TUŠAR

    2014-09-01

    Full Text Available Asphalt is material that can be recycled. In particular reclaimed asphalt (RA contains aged binder, which limits the reuse of RA. In this study the rate of recycled asphalt was increased by adding a rejuvenator containing paraffin. The authors investigated the effect of the rejuvenator in laboratory and in plant prepared samples of asphalt mixture. In laboratory samples with different percentage of RA (0%, 10%, 30%, 50% and rejuvenator were prepared. In asphalt plant only asphalt mixture with highest amount of RA and rejuvenator and control mixture without RA were prepared. On samples were conducted different tests, e.g. determining softening point, Fraass breaking point, penetration, indirect tensile strength. Results on extracted bitumen showed increase in softening point and decrease in Fraass breaking point with increasing percentage of RA and rejuvenator, meaning that service temperature of binders increased. Asphalt samples prepared in asphalt plant were laid on test field. Asphalt with RA and rejuvenator was built in at lower temperature (round 100 °C. Mixtures with RA and rejuvenator have better low temperature properties confirmed with Thermal Stress Restrained Specimen Test (TSRST method, but are less resistant to compaction and less sensitive to water than control mixture. For comparison of long term behaviour wheel tracking test was performed on mixtures built in test field. A week after paving, the control mixture showed better properties, but one year later the results were opposite, asphalt containing RA and rejuvenator was more resistant to rutting. From the results of this experimental study the following was concluded: the amount of RA can be increased by using rejuvenator and the quality of such asphalt mixture is in most cases equal or even better than asphalt mixture made of virgin materials. By using RA we preserve nature, reduce usage of virgin raw materials, but it is cost effective only if recycling degree is high

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

    Science.gov (United States)

    Rizvi, Hashim Raza; 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.

  14. Performance Evaluation of Semiplastic Recycled Cold Asphalt Using Noncement Binders

    Directory of Open Access Journals (Sweden)

    Byung Jae Lee

    2015-01-01

    Full Text Available The optimal mixing conditions for semiplastic recycled cold asphalt, which recycled waste asphalt and used noncement binders (NCB, were assessed through verification of the performance. The NCB of 6% desulfurization gypsum mixing was found to have the most outstanding properties. For the Marshall stability, 4% (NCB filler mixing brought about a 1.92-time strength increase effect compared to OPC (2% and was improved when using modified asphalt and SBR. The flow test results showed that although an increase dosage of filler and SBR decreased the flow value of the semiplastic recycled cold asphalt, an increase dosage of asphalt emulsion improved the flow value. The indirect tensile strength and liquid immersion residual stability for the condition with greatest Marshall stability were most outstanding with 0.95 MPa and 83.6%, respectively. Evaluation of the recycled cold asphalt abrasion durability revealed that for the case of mixing more than 4% NCB the mass loss rate was lower than 20%. The abrasion durability was found to improve when using modified emulsified asphalt and SBR substitution. From the test results, it was found that the optimal mixing proportion of semiplastic recycled cold asphalt satisfied mechanical properties and durability is NCB with 4%, emulsified asphalt with 3%, and SBR substitution with 20%.

  15. 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.

  16. Safety evaluation of asphalt products for final disposal

    International Nuclear Information System (INIS)

    Under the present situation, the wastes concentrated according to the radioactivity level, the properties and the environmental conditions are usually solidified in view of limiting the escape of the radioactive substances to the environment as small as possible by containment. The materials used for the solidification are cement, asphalt, plastics, ceramics and so on, and the selection is made by taking the kinds and radioactivity level of wastes, final disposing method, economy and handling into consideration. Asphalt is more suitable than cement to the wastes coming from PWR power plants, which contain boric acid for controlling nuclear reaction, and the effect of reducing the volume of wastes is high. It is economical when a certain scale is reached, accordingly recently, the use of asphalt for the solidification of wastes is going to increase. For the solidification of low level wastes, straight-run asphalt is suitable, and for high level wastes, heat-resistant blown asphalt is suitable. Asphalt-solidified bodies can contain 40-60 wt.% of wastes without any problem. The present situation of asphalt solidification in foreign countries, the physical properties required for the disposal of asphalt-solidified bodies, and the leaching, combustibility, radiation resistance and form stability of asphalt-solidified bodies are described. (Kako, I.)

  17. Field testing of asphalt-emulsion radon-barrier system

    International Nuclear Information System (INIS)

    Three years of laboratory and field testing have demonstrated that asphalt emulsion seals are effective radon diffusion barriers. Both laboratory and field tests in 1979, 1980 and 1981 have shown that an asphalt emulsion seal can reduce radon fluxes by greater than 99.9%. The effective diffusion coefficient for the various asphalt emulsion admix seals averages about 10-6 cm2/s. The 1981 joint field test is a culmination of all the technology developed to date for asphalt emulsion radon barrier systems. Preliminary results of this field test and the results of the 1980 field test are presented. 18 figures, 6 tables

  18. 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.

  19. Modification of Asphalt by the Use of Crumb Rubber

    Directory of Open Access Journals (Sweden)

    Shah Room

    2014-01-01

    Full Text Available Health aspects enforced to ponder a study on asphalt which incorporate rubber crumbs to increase strength and flexibility of asphalt. Disposal of waste tires is a menace and it’s a serious problem globally because it is not easily biodegradable as these tires consume large spaces, open burning cause serious problems. By the use of rubber tires, this scrap is utilized efficiently and reduces the cost of asphalt to produce economical system. The asphalt is absorbed by the rubber particles which swells at high temperature allowing greater concentration of liquid asphalt. The partial replacement of crumb rubber in asphalt is 5%, 10%, 15%, and 20% (D05, D10, D15, and D20. The analysis of incorporated asphalt was done in hot mix asphalt. The generated results showed that the value for resilient modulus and creep stiffness is more as compared to the conventional asphalt and in the accumulated strain the values are much lesser which is positive approach.

  20. Effects of reclaimed asphalt pavement on indirect tensile strength test of foamed asphalt mix tested in dry condition

    International Nuclear Information System (INIS)

    Indirect tensile strength (ITS) test was conducted to analyse strength of the foamed asphalt mixes incorporating reclaimed asphalt pavement. Samples were tested for ITS after cured in the oven at 40°C for 72 hours. This testing condition known as dry condition or unconditioned. Laboratory results show that reclaimed asphalt pavement (RAP) contents insignificantly affect the ITS results. ITS results significantly affected by foamed bitumen contents.

  1. Effects of reclaimed asphalt pavement on indirect tensile strength test of foamed asphalt mix tested in dry condition

    Science.gov (United States)

    Yati Katman, Herda; Rasdan Ibrahim, Mohd; Yazip Matori, Mohd; Norhisham, Shuhairy; Ismail, Norlela

    2013-06-01

    Indirect tensile strength (ITS) test was conducted to analyse strength of the foamed asphalt mixes incorporating reclaimed asphalt pavement. Samples were tested for ITS after cured in the oven at 40°C for 72 hours. This testing condition known as dry condition or unconditioned. Laboratory results show that reclaimed asphalt pavement (RAP) contents insignificantly affect the ITS results. ITS results significantly affected by foamed bitumen contents.

  2. Classification of recycled asphalt (RA) material

    OpenAIRE

    Wendling, Louisette; DE LA ROCHE SAINT ANDRE, Chantal; Gaudefroy, Vincent; MARSAC, Paul; TEBALDI, Gabriele; DAVE, Eshan; HUGENER, Martin; BOCCI, Maurizio; Loizos, Andreas; JENKINS, Kim; MARRADI, Alessandro; Grilli, Andrea; GRAZIANI, Andrea; Pasetto, Marco; MURAYA, Patrick

    2012-01-01

    Use of recycled asphalt pavements (RA) in pavement rehabilitation processes is continuously growing as recycling techniques, such as cold recycling (CR), are being utilized in increasing magnitude. The focus of this paper is on developing a state of the art and state of the practice summary of processes used for classification of RA. A variety of topics were explored through an exhaustive literature search, these include RAP production methods, definition of RA materials, stockpiling practice...

  3. Active carbon production from modified asphalt

    International Nuclear Information System (INIS)

    A granular activated carbons (GACs) have been prepared from some local raw materials such as Qiayarah asphalt (QA) after some modification treatments of this asphalt by various ratios of its original constituents (asphaltenes and maltens) at 180 degree C. Thermal carbonization method by sulfur and steam physical activation have been used for AC preparation. The carbons thus prepared were characterized in the term of iodine, methylene blue (MB), P-nitro phenol (PNP) and CCl4 adsorption. The BET surface area of the prepared ACs has been estimated via a calibration curve between iodine numbers and surface area determined from N2 adsorption isotherm from previous studies, also, the surface area of the prepared ACs were determined through another methods such as retention method by ethylene glycol mono ethyl ether (EGME), adsorption from vapor phase using acetone vapor and adsorption from solution method using PNP and MB as solutes. The results referred to the success of modification method for preparing ACs of good micro porosity as compared with the AC from the untreated asphalt as well as the commercial sample. (author)

  4. Method of interrupting asphalt solidifying operation

    International Nuclear Information System (INIS)

    Purpose: To shorten the time required for interrupting operation, by specifying methods of supplying and interrupting liquid wastes, water and asphalts. Method: Electrical power supply for a heat medium heater is disconnected simultaneously with the start for the stopping operation. The temperature for the heat medium is detected by a heat medium thermometer, the flow rate of a waste liquid supply pump is reduced by way of a rotation controller for the liquid waste supply pump and the amount of liquid wastes supplied is gradually decreased along with the reduction in the temperature for the heat medium. Then, when the temperature for the heat medium lowered to about 190 - 2100C, supply of the liquid wastes is interrupted and cleaning water is supplied to a liquid wastes supply tank while closing the liquid wastes supply tank main valve and opening a cleaning water valve to thereby clean the radioactive substances. Then, after stopping the supply of the cleaning water, asphalt is continued to be supplied for several minutes, the radioactive substances deposited in an evaporator and an agitation blade are sufficiently washed out. Then, after stopping the asphalt tank, operations for the driving device and the heat medium pump are stopped. This enables cooling for the heat medium in a short time using no exclusive heat medium cooler, as well as clean the radioactive substances. (Horiuchi, T.)

  5. Dynamic linear viscoelastic properties and extensional failure of asphalt binders

    Science.gov (United States)

    Ruan, Yonghong

    Billions of dollars are spent annually in USA to maintain old pavements that are badly cracked. In order to reduce this expenditure, it is desirable to have criteria for selecting asphalts with superior cracking resistance that will provide pavements with longer durability. Literature reports indicate that the ductility of binders recovered from asphalt pavements correlates with cracking failure. However, ductility measurement is a time and material consuming process, and subject to reproducibility difficulties, as are all failure tests. In addition, ductility measurement does not belong to the currently used Superpave(TM) specification. Correlations between ductility and dynamic viscoelastic properties (measured with the dynamic shear rheometer, DSR), which are much easier and faster to perform and may be included into the Superpave(TM) system, are studied for both straight and modified binders. Ductility correlates quite well with G'/(eta '/G') for conventional asphalt binders aged at different conditions, especially when ductility is below 10 cm. However, for modified asphalts, there is no universal correlation between ductility and G'/(eta'/G'), even in the low ductility region. As far as the asphalt binder in pavement is concerned, the loss due to oxidative aging of its ductility is an important reason for pavement cracking. Polymer modification modifies the rheological and oxidative hardening properties of asphalt binders. The effect of polymeric modifiers on various properties of asphalt binders was investigated. Modifiers studied were diblock poly (styrene-b-butadiene) rubber (SBR), triblock poly (styrene-b-butadiene-b-styrene) (SBS), and tire rubber. Polymer modified binders have a lower hardening and oxidation rate than their corresponding base asphalts. In addition, modified binders have lower hardening susceptibility compared with their base materials and in some cases the results can be dramatic. Polymer modification improves asphalt binders' shear

  6. Hot asphalt burns: a review of injuries and management options.

    Science.gov (United States)

    Bosse, George M; Wadia, Shernaz A; Padmanabhan, Pradeep

    2014-07-01

    Hot asphalt burns to human tissue can increase the likelihood of infection and potential conversion of partial thickness to full-thickness injuries. Successful intervention for hot asphalt burns requires immediate and effective cooling of the asphalt on the tissue followed by subsequent gradual removal of the cooled asphalt. A review of the literature reveals that multiple substances have been used to remove asphalt, including topical antibiotics, petroleum jelly, a commercial product known as De-Solv-It (ORANGE-SOL, Chandler, AZ), sunflower oil, baby oil, liquid paraffin, butter, mayonnaise, and moist-exposed burn ointment (MEBO). Although many of these products may be effective in the removal of asphalt, they may not be readily available in an emergency department setting. Topical antibiotics are readily available, are more commonly described in the medical literature, and would be expected to be effective in the removal of asphalt. We developed guidelines for on scene (first-aid) management and the initial care of such patients upon presentation to a health care facility. These guidelines emphasize the principles of early cooling, gradual removal of adherent asphalt using topical antibiotics, and avoidance of the use of topical agents, which are likely to result in tissue toxicity. PMID:24630605

  7. Hanford Permanent Isolation Barrier Program: Asphalt technology development

    International Nuclear Information System (INIS)

    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

  8. Including asphalt cooling and rolling regimes in laboratory compaction procedures

    NARCIS (Netherlands)

    Bijleveld, F.R.; Doree, A.G.; Kim,

    2014-01-01

    Given the various changes occurring in the asphalt construction industry, improved process and quality control is becoming essential. The significance of appropriate rolling and compaction for the quality of asphalt is widely acknowledged and vital for improved process control. But what constitutes

  9. Durability ofAsphalt in Different Corrosion Solution

    Institute of Scientific and Technical Information of China (English)

    CHEN Shuanfa; GUAN Bowen; XIONG Rui; SHENG Yanping; HE Rui

    2011-01-01

    The corrosion to asphalt mixture under different kinds of corrosion solution,such as pH=2 solution,pH=12 solution,pH =12 solution and 10% Na2SO4 solution,was studied.The performance attenuation of asphalt mixture was analyzed under the normal environment and the freeze-thaw environment,and the analysis was given on the sensitivity of the test results to the evaluation index.The experimental results show that the performance of asphalt mixture is attenuated faster under the acidic solution,alkaline solution and sulfate solution.Corrosion factor Kc,freeze-thaw corrosion factor Kf,and freeze-thaw effect factor Kfc are proposed to evaluate asphalt mixture resistance to corrosion in different kinds of corrosion solution.The values of Kc and Kfc decrease with the increasing of corrosion time.The change rule of Kf show that the rate of corrosion is decreased by the action of freeze-thaw in acidic solution and in alkaline solution,but is increased by the action of freeze-thaw in sulfate solution.The microscopic analysis indicates that acid solution reacts with aggregate of asphalt mixture,alkaline solution reacts with asphalt cement of asphalt mixture,the surface tension of sulfate solution and crystallization of sulfate are the main reasons which weak the performance of asphalt mixture.

  10. 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

  11. Improving the quality of asphalt coating with carbon nanomodifiers

    Science.gov (United States)

    Larisa, Urkhanova; Nikolay, Shestakov; Aleksandr, Semenov; Natalya, Smirnyagina; Irina, Semenova

    2015-07-01

    This article deals with the possibility of modifying the binder by adding carbon nanomodifier to bitumen to improve the quality of asphalt. Addition of 0.05%-0.5% of nanomodifier significantly changes the properties of bitumen. Asphalt with this astringent has increased strength, heat resistance and shear resistance.

  12. 40 CFR 443.30 - Applicability; description of the asphalt roofing subcategory.

    Science.gov (United States)

    2010-07-01

    ... asphalt roofing subcategory. 443.30 Section 443.30 Protection of Environment ENVIRONMENTAL PROTECTION... MATERIALS (TARS AND ASPHALT) POINT SOURCE CATEGORY Asphalt Roofing Subcategory § 443.30 Applicability; description of the asphalt roofing subcategory. The provisions of this subpart are applicable to...

  13. 40 CFR 443.40 - Applicability; description of the linoleum and printed asphalt felt subcategory.

    Science.gov (United States)

    2010-07-01

    ... linoleum and printed asphalt felt subcategory. 443.40 Section 443.40 Protection of Environment... PAVING AND ROOFING MATERIALS (TARS AND ASPHALT) POINT SOURCE CATEGORY Linoleum and Printed Asphalt Felt Subcategory § 443.40 Applicability; description of the linoleum and printed asphalt felt subcategory....

  14. 40 CFR 443.10 - Applicability; description of the asphalt emulsion subcategory.

    Science.gov (United States)

    2010-07-01

    ... asphalt emulsion subcategory. 443.10 Section 443.10 Protection of Environment ENVIRONMENTAL PROTECTION... MATERIALS (TARS AND ASPHALT) POINT SOURCE CATEGORY Asphalt Emulsion Subcategory § 443.10 Applicability; description of the asphalt emulsion subcategory. The provisions of this subpart are applicable to...

  15. Mechanical Properties of Asphalt Pavement Structure in Highway Tunnel

    Institute of Scientific and Technical Information of China (English)

    SHI Chun-xiang; GUO Zhong-yin

    2008-01-01

    A linear full 3D finite element method (FEM) was performed in order to present the key design parameters of highway tunnel asphalt pavement under double-wheel load on rectangular loaded area considering horizontal contact stress induced by the acceleration/deceleration of vehicles. The key design parameters are the maximum horizontal tensile stresses at the surface of the asphalt layer, the maximum horizontal tensile stresses at the bottom of the asphalt layer and the maximum vertical shear stresses at the surface of the as- phalt layer were calculated. The influencing factors such as double-wheel weight; asphalt layer thickness; base course stiffness modulus and thickness; and the contact conditions among the structure layers on these key design parameters were also examined separately to propose construction procedures of highway tunnel asphalt pavement.

  16. Monitoring asphalt pavement damages using remote sensing techniques

    Science.gov (United States)

    Mettas, Christodoulos; Themistocleous, Kyriacos; Neocleous, Kyriacos; Christofe, Andreas; Pilakoutas, Kypros; Hadjimitsis, Diofantos

    2015-06-01

    One of the main issues in the maintenance plans of road agencies or governmental organizations is the early detection of damaged asphalt pavements. The development of a smart and non-destructive systematic technique for monitoring damaged asphalt pavements is considered a main priority to fill this gap. During the 1970's, remote sensing was used to map road surface distress, while during the last decade, remote sensing became more advanced, thereby assisting in the evolution of the identification and mapping of roads. Various techniques were used in order to explore condition, age, weaknesses and imperfections of asphalted pavements. These methods were fairly successful in the classification of asphalted surfaces and in the detection of some of their characteristics. This paper explores the state of the art of using remote sensing techniques for monitoring damaged pavements and some typical spectral profiles of various asphalt pavements in Cyprus area acquired using the SVC1024 field spectroradiometer.

  17. 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.

  18. 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.

  19. Concrete evidence

    Energy Technology Data Exchange (ETDEWEB)

    Provis, J.; Duxson, P.; van Deventer, J. [University of Melbourne, Vic. (Australia)

    2008-11-15

    The time is right for a revolution in the cement industry which is responsible for 5-8% of all human-derived carbon dioxide emissions. Zeobond, an Australian company, has developed E-Crete which is a geopolymer concrete using fly ash and blast furnace slags which reduces CO{sub 2} emissions by 80% from the 0.67t of CO{sub 2} per ton of cement emitted by the Australian triple blend of cement, fly ash and slag. The article discusses the products development, standards for cements and challenges to the commercialization of E-Crete. 5 refs., 3 figs.

  20. Field site leaching from recycled concrete aggregates applied as sub-base material in road construction.

    Science.gov (United States)

    Engelsen, Christian J; Wibetoe, Grethe; van der Sloot, Hans A; Lund, Walter; Petkovic, Gordana

    2012-06-15

    The release of major and trace elements from recycled concrete aggregates used in an asphalt covered road sub-base has been monitored for more than 4 years. A similar test field without an asphalt cover, directly exposed to air and rain, and an asphalt covered reference field with natural aggregates in the sub-base were also included in the study. It was found that the pH of the infiltration water from the road sub-base with asphalt covered concrete aggregates decreased from 12.6 to below pH 10 after 2.5 years of exposure, whereas this pH was reached within only one year for the uncovered field. Vertical temperature profiles established for the sub-base, could explain the measured infiltration during parts of the winter season. When the release of major and trace elements as function of field pH was compared with pH dependent release data measured in the laboratory, some similar pH trends were found. The field concentrations of Cd, Ni, Pb and Zn were found to be low throughout the monitoring period. During two of the winter seasons, a concentration increase of Cr and Mo was observed, possibly due to the use of de-icing salt. The concentrations of the trace constituents did not exceed Norwegian acceptance criteria for ground water and surface water Class II. PMID:22554532

  1. Concrete construction engineering handbook

    CERN Document Server

    Nawy, Edward G

    2008-01-01

    Provides coverage of concrete construction engineering and technology. This work features discussions focusing on: the advances in engineered concrete materials; reinforced concrete construction; specialized construction techniques; and, design recommendations for high performance.

  2. 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.

  3. Computed tomography to determine fatigue cracking growth parameters in asphaltic mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Braz, D.; Lopes, R.T. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Lab. de Instrumentacao Nuclear; Motta, L.M.G. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Lab. Geotecnico

    2002-07-01

    Distress of asphalt concrete pavement due to repeated bending from traffic loads has been a well recognized problem in Brazil. There are three primary causes of cracking, namely fatigue cracking, due to the repetitive nature of traffic loading, reflection cracking which results from the presence of a defect which may be a crack or joint in other layers in the pavement, and low temperature cracking which is caused by a rapid and large decrease in ambient temperature. If it is assumed that fatigue cracking growth is governed by the conditions at the crack tip, and that the crack tip conditions can be characterized by the stress intensity factor, then fatigue cracking growth as a function of stress intensity range {delta}K can be determined. Computed tomography technique is used to detect crack evolution in asphaltic mixtures which were submitted to fatigue tests. Fatigue tests under conditions of controlled stress were carried out using diametral compression equipment and repeat loading. The aim of this work is imaging several specimens at different stages of the fatigue tests, i.e., after different numbers of applied blows. In order to obtain the behavior of the crack growth for each specimens to both mixtures graphics were made to represent crack size (c) as a function of the applied loading number (N). A graphical representation of fatigue cracking growth rates (dc/dN) as a function of {delta}K is also presented. (author)

  4. Research on fatigue cracking growth parameters in asphaltic mixtures using computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Braz, D. E-mail: delson@lin.ufrj.br; Lopes, R.T.; Motta, L.M.G

    2004-01-01

    Distress of asphalt concrete pavement due to repeated bending from traffic loads has been a well-recognized problem in Brazil. If it is assumed that fatigue cracking growth is governed by the conditions at the crack tip, and that the crack tip conditions can be characterized by the stress intensity factor, then fatigue cracking growth as a function of stress intensity range {delta}K can be determined. Computed tomography technique is used to detect crack evolution in asphaltic mixtures which were submitted to fatigue tests. Fatigue tests under conditions of controlled stress were carried out using diametral compression equipment and repeat loading. The aim of this work is imaging several specimens at different stages of the fatigue tests. In preliminary studies it was noted that the trajectory of a crack was influenced by the existence of voids in the originally unloaded specimens. Cracks would first be observed in the central region of a specimen, propagating in the direction of the extremities. Analyzing the graphics, that represent the fatigue cracking growth (dc/dN) as a function of stress intensity factor ({delta}K), it is noticed that the curve has practically shown the same behavior for all specimens at the same level of the static tension rupture stress. The experimental values obtained for the constants A and n (of the Paris-Erdogan Law) present good agreement with the results obtained by Liang and Zhou.

  5. 沥青路面冷再生技术在路面维修中的应用%Application of Cold Recycling Technology of Asphalt Pavement in the Pavement Repair

    Institute of Scientific and Technical Information of China (English)

    冯国龙

    2014-01-01

    This paper analyzed several main causes of the damage of asphalt pavement and simply introduced the main techniques of the cold recycling technology of asphalt pave-ment. The author also introduced the concrete applying meth-ods of the cold regeneration technique of asphalt pavement in pavement repair.%本文针对沥青路面出现损坏的几个主要原因进行了分析,简单介绍了沥青路面冷再生技术的主要工艺,并且介绍了沥青路面冷再生技术在路面维修中的具体使用方法。

  6. Evaluation of Warm Mix Asphalt Technologies and Recycled Asphalt Pavements in Truckee Meadows, Nevada

    Science.gov (United States)

    Diaz Montecino, Cristian

    This study evaluated the properties and laboratory-performance of Hot Mix Asphalt (HMA) and Warm Mix Asphalt (WMA) mixtures with different levels of Recycled Asphalt Pavements (RAP) content: none for control mixtures, around 15% by dry weight of aggregates, and more than 30% by dry weight of aggregates. The rheological properties were evaluated for virgin and recovered RAP asphalt binders. The target amount of RAP in the mixtures was determined by using Blending Charts and Mortar Experiments. The mixtures are design through the guidelines established in Marshall Mix Design Method considering additional modifications for RAP and WMA from Superpave Mix Design. The mixtures are evaluated for their resistance to moisture damage by means of measuring the Dynamic Modulus |E*| after three freeze/thaw cycles and the indirect tensile strength after one and three freeze/thaw cycles. The resistance of the mixtures to permanent deformation was also evaluated by using the Asphalt Mixture Performance Tester (AMPT) to measure the flow number (FN). For this study, it was determined that the resistance to moisture damage decreases as the number of freeze/thaw cycles increases for most of the evaluated mixtures. Mixtures exhibited an increase in dynamic modulus as the RAP percentage increased. A decrease in the resistance to moisture damage was detected with the increase in RAP content for most of the mixtures. HMA mixtures exhibited a better performance in rutting than the WMA mixtures. An increase in rutting resistance was observed with the increase in RAP percentage for HMA mixtures whereas an inconsistent trend was observed for WMA mixtures. Further study is needed to validate the use of the high percentage of RAP in Washoe County.

  7. Some Properties of Emulsified Asphalt Paving Mixture at Iraqi Environmental Conditions

    OpenAIRE

    Shakir.A.Al-Mishhadani; Hasan.H.Al-Baid

    2014-01-01

    Cold emulsified asphalt mixture is generally a mix made of emulsified asphalt withaggregate. Emulsified asphalt is manufactured from base asphalt, emulsifier agent and waterwith approximate percentage of 40% to 75% asphalt, 0.1% to 2.5% emulsifier and 25% to60% water plus some minor components. This study aims to use the cold emulsified asphaltmixtures for road construction and maintenance in Iraq as an alternative to the hot asphaltmixtures, due to its economical, practical and environmental...

  8. Decision of National and Provincial Highway Asphalt Pavement Structure Based on Value Engineering

    OpenAIRE

    Yingwei Ren; Jingsong Shan

    2014-01-01

    It is important that decision of asphalt pavement structure requires overall considerations of the performance and financial investment. To have asphalt pavement structure fulfilling good reliability, the asphalt pavement structure decision was researched based on value engineering theory. According to the national and provincial highway investigation data in Shandong Province during the last decade, the asphalt pavement performance attenuation rules of traffic levels and asphalt layer thickn...

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

    OpenAIRE

    Hui Yao; Zhanping You

    2016-01-01

    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 ...

  10. Modeling and Simulation of Flow and Formation Damage of Asphalt-Paved Roads

    OpenAIRE

    M. H. Alawi; M. M. El-Qadi; M. A. El-Ameen

    2013-01-01

    Porous asphalt is a standard asphalt built on aggregate storage bed which allows water to drain through it and reduces stormwater runoff. However, porosity of the porous asphalt and the storage bed may be effectively reduced due to trapping suspended solids from the water or from the asphalt damage. In this paper, we present mathematical modeling and numerical simulation of flow and damage of porous asphalt-paved roads. A mathematical model to describe the fine-particles transport carried by ...

  11. 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.

  12. Performance-based asphalt mixture design methodology

    Science.gov (United States)

    Ali, Al-Hosain Mansour

    Today, several State D.O.T.s are being investigating the use of tire rubber with local conventional materials. Several of the ongoing investigations identified potential benefits from the use of these materials, including improvements in material properties and performance. One of the major problems is being associated with the transferability of asphalt rubber technology without appropriately considering the effects of the variety of conventional materials on mixture behavior and performance. Typically, the design of these mixtures is being adapted to the physical properties of the conventional materials by using the empirical Marshall mixture design and without considering fundamental mixture behavior and performance. Use of design criteria related to the most common modes of failure for asphalt mixtures, such as rutting, fatigue cracking, and low temperature thermal cracking have to be developed and used for identifying the "best mixture," in term of performance, for the specific local materials and loading conditions. The main objective of this study was the development of a mixture design methodology that considers mixture behavior and performance. In order to achieve this objective a laboratory investigation able to evaluate mixture properties that can be related to mixture performance, (in terms of rutting, low temperature cracking, moisture damage and fatigue), and simulating the actual field loading conditions that the material is being exposed to, was conducted. The results proved that the inclusion of rubber into asphalt mixtures improved physical characteristics such as elasticity, flexibility, rebound, aging properties, increased fatigue resistance, and reduced rutting potential. The possibility of coupling the traditional Marshall mix design method with parameters related to mixture behavior and performance was investigated. Also, the SHRP SUPERPAVE mix design methodology was reviewed and considered in this study for the development of an integrated

  13. 再生混凝土粒料在路面降噪中的应用研究%Application Research on Recycled Concrete Aggregates Used in Low-noise Pavement

    Institute of Scientific and Technical Information of China (English)

    阮志刚

    2014-01-01

    This paper introduces the use of recycled concrete aggregates to replace part of the natural coarse aggregate porous asphalt concrete mixing to explore the feasibility of recycled concrete aggregates used in low-noise pavement. Using high viscosity modified asphalt and cement asphalt paste two bonding porous asphalt concrete mixing material specimens, this paper discusses in two stages recycled concrete aggregates used in the feasibility of low noise pavement. The results show that the study of asphalt cement mortar as a binder, mixing porous asphalt concrete mixing temperature is not required, which can effectively reduce air pollution and energy consumption, and the mechanical properties, durability and road performance is good.%采用废弃混凝土再生集料取代部分天然粗集料拌制多孔隙沥青混凝土,以探讨废弃混凝土再生集料应用于低噪声路面的可行性。研究时采用高黏改性沥青及水泥沥青胶浆两种黏结料拌制多孔隙沥青混凝土试件,并分两阶段探讨废弃混凝土再生集料应用于低噪声路面的可行性。研究表明,采用水泥沥青胶浆作为黏结料拌制多孔隙沥青混凝土无须高温拌合,可有效降低空气污染及能源消耗,具有较好的力学性质、耐久性质及路用性能。

  14. Microbial Life in a Liquid Asphalt Desert

    CERN Document Server

    Schulze-Makuch, Dirk; Antonio, Marina Resendes de Sousa; Ali, Denzil; Hosein, Riad; Song, Young C; Yang, Jinshu; Zaikova, Elena; Beckles, Denise M; Guinan, Edward; Lehto, Harry J; Hallam, Steven J

    2010-01-01

    An active microbiota, reaching up to 10 E+7 cells/g, was found to inhabit a naturally occurring asphalt lake characterized by low water activity and elevated temperature. Geochemical and molecular taxonomic approaches revealed novel and deeply branching microbial assemblages mediating anaerobic hydrocarbon degradation, metal respiration and C1 utilization pathways. These results open a window into the origin and adaptive evolution of microbial life within recalcitrant hydrocarbon matrices, and establish the site as a useful analog for the liquid hydrocarbon environments on Saturn's moon Titan.

  15. Finite element simulation of asphalt fatigue testing

    DEFF Research Database (Denmark)

    Ullidtz, Per; Kieler, Thomas Lau; Kargo, Anders

    1997-01-01

    damage mechanics.The paper describes how continuum damage mechanics may be used with a finite element program to explain the progressive deterioration of asphalt mixes under laboratory fatigue testing. Both constant stress and constant strain testing are simulated, and compared to the actual results from...... three point and four point fatigue test on different mixes. It is shown that the same damage law, based on energy density, may be used to explain the gradual deterioration under constant stress as well as under constant strain testing.Some of the advantages of using this method for interpreting fatigue...

  16. Concrete durability

    Directory of Open Access Journals (Sweden)

    Gaspar Tébar, Demetrio

    1991-03-01

    Full Text Available The evidence that the concrete is not a material for ever was noticed from the beginning of its industrial use. In the present work, the author describes the studies carried out during the last century and the early ages of the present one, mainly devoted to the study of the durability in sea water. At the present days, and in spite of the numerous papers published from then, the study of the concrete durability continues focusing the research priorities and economical resources of researchers and industries related with this material. Moreover, the new laboratory techniques are allowing to understand old problems and even to open again the discussion on reaction mechanisms which were believed to be completely understood. The article finalizes with a brief description of the numerous studies carried out at the Institute Eduardo Torroja on concrete durability, mainly those related with the resistance against gypsum attack (so abundant in our country land and against sea water attack.

    La realidad de que el hormigón no es un material eterno y es susceptible de sufrir ataques por agentes químicos, fue constatada desde el comienzo mismo de su uso industrial. En el presente trabajo el autor enumera los estudios realizados el siglo pasado y a comienzos del presente sobre la durabilidad del hormigón en agua de mar. En la actualidad y a pesar de los numerosos trabajos desarrollados desde entonces, el estudio de la durabilidad del hormigón sigue centrando la atención prioritaria y los recursos económicos de los investigadores e industrias relacionadas con este material. Además las nuevas técnicas de estudio están permitiendo comprender antiguos problemas e incluso reabrir la discusión sobre mecanismos de reacción que se creían completamente explicados. Finaliza el artículo con una descripción somera de los múltiples trabajos realizados en el Instituto Eduardo Torreja sobre la materia, en especial los estudios realizados sobre

  17. Study on the hardening mechanism of cement asphalt binder

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The hydration and hardening mechanism of cement asphalt binder(CAB) was studied.The early hydration process,hydration products and paste microstructure of CAB made by Portland cement and anionic asphalt emulsion were investigated by calorimetry,X-ray diffraction,and environmental scanning electron microscopy.The early hydration process of CAB can be characterized as 5 stages similar to those of Portland cement.There is no chemical reaction detected between cement and asphalt,hence no new hydration products other than those of Portland cement are produced.The hardening of CAB begins with the hydration of cement.When the hydration of cement comes into the acceleration period and its exothermic rate comes to the maximum,the coalescence of asphalt particles in asphalt emulsion is triggered.In the hardened system of CAB,it was found that the hydration products of cement form the skeleton and are covered by the continuous asphalt film.They formed an interpenetrating network system.The emulsifiers in the asphalt emulsion may retard the hydration process of cement.

  18. 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.

  19. A Study on Properties of Lean Cement with Emulsified Asphalt%外掺乳化沥青贫混凝土性能研究

    Institute of Scientific and Technical Information of China (English)

    杨明熹; 孙重静

    2016-01-01

    The mechanical testing system is used to measure compressive strength,flexural strength, compressive modulus and flexural modulus of three kinds of lean concrete with different emulsified as-phalt content.The shrinkage of lean concrete with different emulsified asphalt is measured under the condition without curing and normal curing.Results indicate that the compressive strength and flexur-al strength decline with the increasing of emulsified asphalt content,because asphalt membrane re-tards the hydration process of cement.The compressive modulus and flexural modulus decline and the deformation behavior of lean concrete is improved.Also the drying shrinkage and cracking of lean con-crete decrease,the flexibility of base is improved and service life of road increases with the increasing of emulsified asphalt content.%通过 MTS测量了3种乳化沥青掺量的碾压贫混凝土的无侧限抗压强度、弯拉强度、抗压模量和弯拉模量,以及在无养护与正常养护条件下的收缩读数。结果表明,乳化沥青掺量增加,贫混凝土的无侧限抗压强度和弯拉强度有所下降,主要是沥青粘聚成膜阻碍水泥水化进程,影响强度形成;贫混凝土的抗压弹性模量和抗弯拉弹性模量降低,贫混凝土的变形性能改善,且具有一定的柔韧性;贫混凝土干缩与开裂减少,基层柔韧度改善,道路使用寿命延长。

  20. Asphalt emulsion sealing of uranium mill tailings

    International Nuclear Information System (INIS)

    The use of asphalt emulsion to contain radon and radium in uranium tailings is being investigated at the Pacific Northwest Laboratory. Results of these studies indicate that a radon flux reduction of greater than 99% can be obtained using either a poured-on/sprayed-on seal (3.0 to 7.0 mm thick) or an admix seal (2.5 to 15.2 cm thick) containing about 18 wt % residual asphalt. A field test was carried out at the Grand Junction tailings pile in order to demonstrate the sealing process. A reduction in radon flux ranging from 4.5 to greater than 99% (76% average) was achieved using a 15.2 cm (6 in.) admix seal with a sprayed-on top coat. A hydrostatic stabilizer was used to apply the admix. This was followed by compaction to form the radon seal. Overburden was applied to provide a protective soil layer over the seal. Included in part of the overburden was a herbicide to prevent root penetration

  1. Conversion of asphalt into distillate products

    International Nuclear Information System (INIS)

    This paper reports the conversion of asphalt in a micro-autoclave under an inert atmosphere of nitrogen to lighter products. The influence of temperature, contact time and some catalysts, i.e. clay type; UTIMAC, HZSM-5 and sodium silicate, acidic type; phospho-tungstic acid, oxide type; ammonium hepta molybdate, silica gel, nickel oxide and alumina powder, chloride type; stannous chloride and aluminum chloride and modifiers like methyl iodide and coal, on the yield of liquid and gas products was studied. A marked effect of temperature on the yield of liquid as well as gas products was observed. Employment of clay type catalysts was found to be beneficial in term of yields of liquid products. Among the catalysts used; UTIMAC clay caused the maximum conversion to desired products. The other catalysts caused a decline in the yield of desired products because of coke formation due to condensation reactions catalyzed by these catalysts. The effect of concentration in the case of clay as catalyst was also studied, and synergistic effects were observed in terms of desired product yield. The study will be helpful in planning asphalt conversion processes into light oil fractions

  2. Steep-Slope Assembly Testing of Clay and Concrete Tile With and Without Cool Pigmented Colors

    Energy Technology Data Exchange (ETDEWEB)

    Miller, William A [ORNL

    2005-11-01

    Cool color pigments and sub-tile venting of clay and concrete tile roofs significantly impact the heat flow crossing the roof deck of a steep-slope roof. Field measures for the tile roofs revealed a 70% drop in the peak heat flow crossing the deck as compared to a direct-nailed asphalt shingle roof. The Tile Roofing Institute (TRI) and its affiliate members are keenly interested in documenting the magnitude of the drop for obtaining solar reflectance credits with state and federal "cool roof" building efficiency standards. Tile roofs are direct-nailed or are attached to a deck with batten or batten and counter-batten construction. S-Misson clay and concrete tile roofs, a medium-profile concrete tile roof, and a flat slate tile roof were installed on fully nstrumented attic test assemblies. Temperature measures of the roof, deck, attic, and ceiling, heat flows, solar reflectance, thermal emittance, and the ambient weather were recorded for each of the tile roofs and also on an adjacent attic cavity covered with a conventional pigmented and directnailed asphalt shingle roof. ORNL measured the tile's underside temperature and the bulk air temperature and heat flows just underneath the tile for batten and counter-batten tile systems and compared the results to the conventional asphalt shingle.

  3. Discrete Element Simulation of Asphalt Mastics Based on Burgers Model

    Institute of Scientific and Technical Information of China (English)

    LIU Yu; FENG Shi-rong; HU Xia-guang

    2007-01-01

    In order to investigate the viscoelastic performance of asphalt mastics, a micro-mechanical model for asphalt mastics was built by applying Burgers model to discrete element simulation and constructing Burgers contact model. Then the numerical simulation of creep tests was conducted, and results from the simulation were compared with the analytical solution for Burgers model. The comparision snowed that the two results agreed well with each other, suggesting that discrete element model based on Burgers model could be employed in the numerical simulation for asphalt mastics.

  4. 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

  5. Influence of conductive additive on temperature susceptibility of asphalt binders

    Institute of Scientific and Technical Information of China (English)

    吴少鹏; 李波; 陈筝; 黄旭

    2008-01-01

    The effects of graphite on temperature susceptibility of asphalt binders were investigated by penetration test,Ring & Ball softening point test and viscosity test.And penetration index(IP),viscosity-temperature susceptibility(SVT),and penetration-viscosity numbers(NPV) were introduced to evaluate the effects.The results show that the penetration,softening point and viscosity of asphalt binder increase with the increase of content of graphite.This means that the addition of graphite makes asphalts stiffer.The results from IP,NPV and SVT show that temperature susceptibility is reduced by the addition of graphite.

  6. Self-Compacting Concrete

    OpenAIRE

    Okamura, Hajime; OUCHI, Masahiro

    2003-01-01

    Self-compacting concrete was first developed in 1988 to achieve durable concrete structures. Since then, various investigations have been carried out and this type of concrete has been used in practical structures in Japan, mainly by large construction companies. Investigations for establishing a rational mix-design method and self-compactability testing methods have been carried out from the viewpoint of making self-compacting concrete a standard concrete.

  7. 论沥青路面早期损坏的预防措施%Discussion on prevention measures of early damages of asphalt pavement

    Institute of Scientific and Technical Information of China (English)

    汪香莲

    2011-01-01

    Combining with the present asphalt concrete pavement construction and caused pavement early damages,this paper analysed the reasons and preventive measures of pavement early damages from pavement structure layer,mixing ratio design,raw materials,construction control and other aspects,in order to reduce the early damage of asphalt pavement,prolong the service life of pavement.%结合当前沥青混凝土路面施工及产生的路面早期破坏,从路面结构层、配合比设计、原材料、施工控制等方面分析了路面早期破坏的原因及预防措施,以减少沥青路面早期损坏,延长路面使用寿命。

  8. A review of the fundamentals of polymer-modified asphalts: Asphalt/polymer interactions and principles of compatibility.

    Science.gov (United States)

    Polacco, Giovanni; Filippi, Sara; Merusi, Filippo; Stastna, George

    2015-10-01

    During the last decades, the number of vehicles per citizen as well as the traffic speed and load has dramatically increased. This sudden and somehow unplanned overloading has strongly shortened the life of pavements and increased its cost of maintenance and risks to users. In order to limit the deterioration of road networks, it is necessary to improve the quality and performance of pavements, which was achieved through the addition of a polymer to the bituminous binder. Since their introduction, polymer-modified asphalts have gained in importance during the second half of the twentieth century, and they now play a fundamental role in the field of road paving. With high-temperature and high-shear mixing with asphalt, the polymer incorporates asphalt molecules, thereby forming a swallowed network that involves the entire binder and results in a significant improvement of the viscoelastic properties in comparison with those of the unmodified binder. Such a process encounters the well-known difficulties related to the poor solubility of polymers, which limits the number of macromolecules able to not only form such a structure but also maintain it during high-temperature storage in static conditions, which may be necessary before laying the binder. Therefore, polymer-modified asphalts have been the subject of numerous studies aimed to understand and optimize their structure and storage stability, which gradually attracted polymer scientists into this field that was initially explored by civil engineers. The analytical techniques of polymer science have been applied to polymer-modified asphalts, which resulted in a good understanding of their internal structure. Nevertheless, the complexity and variability of asphalt composition rendered it nearly impossible to generalize the results and univocally predict the properties of a given polymer/asphalt pair. The aim of this paper is to review these aspects of polymer-modified asphalts. Together with a brief description of

  9. 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.

  10. Performance Characterization of Polymer Modified Asphalt Binders and Mixes

    Directory of Open Access Journals (Sweden)

    Nikhil Saboo

    2016-01-01

    Full Text Available Fatigue sensitivity of four different asphalt binders and three different asphalt mixes was evaluated in the study. Binders were subjected to Linear Amplitude Sweep (LAS test at three temperatures of 10, 20, and 30°C. Four-point beam bending test (4PBBT was conducted on the asphalt mixes at a temperature of 20°C for strain amplitudes varying from 200 to 1000 microstrains. Tests like retained Marshall Stability and indirect tensile strength (ITS were also carried out to judge the mix performance. Experimental studies demonstrated that elastomeric modified binder and mixes gave the best performance in fatigue. Plastomeric modification was found to be highly strain susceptible and resulted in poor fatigue performance. The fatigue life of stone mastic asphalt (SMA was found to be almost five times higher than the dense graded mixes. For similar strain levels, the results of LAS test could be linearly correlated with the 4PBBT results.

  11. Effect of moisture on the aging behavior of asphalt binder

    Science.gov (United States)

    Ma, Tao; Huang, Xiao-Ming; Mahmoud, Enad; Garibaldy, Emil

    2011-08-01

    The moisture aging effect and mechanism of asphalt binder during the in-service life of pavement were investigated by laboratory simulating tests. Pressure aging vessel (PAV) test simulating the long-term aging of binder during the in-service life of pavement was modified to capture the long-term moisture aging effect of binder. Penetration grade tests including penetration test, soften point test, and ductility test as well as Superpave™ performance grade tests including viscosity test, dynamic shear rheometer test, and bending beam rheometer test were conducted to fully evaluate the moisture aging effect of binder. Fourier transform infrared spectroscopy test and Gel-permeation chromatography test were applied to provide a fundamental understanding of the moisture aging mechanism of binder. The results indicate that moisture condition can accelerate the aging of asphalt binder and shorten the service life of asphalt binder. The modified PAV test with moisture condition can well characterize the moisture aging properties of asphalt binder.

  12. Building Asphalt Pavement with SBS-based Compound Added Using a Dry Process in Greenland

    DEFF Research Database (Denmark)

    Lee, Hosin; Kim, Yongjoo; Geisler, Nivi;

    2009-01-01

    -based compound seemed to affect the asphalt mix to become more flexible under the heavy loads. By adding SBS-based compound to asphalt mixtures using a “dry” process, it is expected that the pavement would become more resistant to rutting than a typical asphalt mixture used in Greenland while enduring its arctic...... PMA where it is formulated to melt and blend with asphalt quickly during a batch mixing process. The main objectives of this study are to (1) build asphalt pavement using asphalt mixtures with SBS-based compound added using a “dry” process at the batch plant and (2) evaluate its performance under...

  13. THE EFFECT OF FLOOD CAUSED BY CLIMATE CHANGE TO POROUS ASPHALT PAVEMENT

    OpenAIRE

    Firdaus Chairuddin*, Wihardi Tjaronge

    2016-01-01

    The test Indirect Tensile Strength for asphalt quality 3%, 4%, 5% are 0.0673, 0.325, 0.2370 subsequently. Cantabro test, loss weight for asphalt quality 3%, 4%, 5% are 77.10, 14.56, 9.70 subsequently. Coefficient vertical test  permeability 0.1795  for asphalt  3%,  0.2029 for asphalt  4%, and 0.1596 for asphalt 5%, Unconfined Compressive Strength, Modulus elasticity 146.543 and ratio poisson 0.095831 for asphalt 3%, Modulus elasticity 91.450 and Ratio poisson 0.20600...

  14. 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.

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

    OpenAIRE

    2014-01-01

    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...

  16. Mechanistic and Economical Characteristics of Asphalt Rubber Mixtures

    OpenAIRE

    Mena I. Souliman; Annie Eifert

    2016-01-01

    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 Ru...

  17. The temperature effect on the reflective cracking of asphalt overlays

    OpenAIRE

    Minhoto, Manuel; Pais, Jorge; Pereira, Paulo

    2008-01-01

    This paper presents a study about the influence of temperature on the reflective cracking in a flexible road pavement through the evaluation of the asphalt overlay damage associated to traffic and temperature variations throughout a year. This study was developed from a numerical simulation of the asphalt overlay behaviour based on a three-dimensional finite-element analysis, considering the simultaneous loading of traffic and temperature variations. A mechanistic-based overlay design method ...

  18. Effect of base bitumen composition on asphalt rubber binder properties

    OpenAIRE

    Partl, M.N.; Ould-Henia, M.; Dumont, A.-G.

    2008-01-01

    The asphalt rubber blend properties are strongly related to its base components properties. The base bitumen composition is considered as a key factor influencing the final rheological properties of asphalt rubber binder. This paper describes results from a laboratory investigation of the interaction between crumb rubber and different composition bitumen according to the wet process. The bitumen composition is determined according to the SARA decomposition approac...

  19. Asphalt in carbon-14-dated archaeological samples from Terqa, Syria

    International Nuclear Information System (INIS)

    The results are reported of an organic geochemical study to verify contamination in 14C dated archaeological samples, which could account for much older apparent ages than expected. The data indicate that ancient asphalt must be the source of contamination, showing that caution should be exercised, in interpreting 14C dates of archaeological samples from areas containing asphalt or other fossil fuel deposits. (U.K.)

  20. Asphalt Carriers from Kraljevica Shipyard – Constructional and Technological Aspects

    OpenAIRE

    Grubišić, R.

    2006-01-01

    After presenting the design development of the asphalt carrier Asphalt Seminole and her sister-ships in the article published in the previous issue of Brodogradnja (No. 1/2006), in this article the structural analysis made in the design stage and some constructional and technological specifities during the building stage are presented. Special emphasis is given to the presentation of the structional connection between the hull and the cargo tanks with the description of the elastic vertical s...

  1. 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.

  2. Reinforcement of Recycled Foamed Asphalt Using Short Polypropylene Fibers

    Directory of Open Access Journals (Sweden)

    Yongjoo Kim

    2013-01-01

    Full Text Available This paper presents the reinforcing effects of the inclusion of short polypropylene fibers on recycled foamed asphalt (RFA mixture. Short polypropylene fibers of 10 mm length with a 0.15% by weight mixing ratio of the fiber to the asphalt binder were used. The Marshall stability test, the indirect tensile strength test, the resilient modulus test, and wheel tracking test of the RFA mixtures were conducted. The test results were compared to find out the reinforcing effects of the inclusion of the fiber and the other mixtures, which included the conventional recycled foamed asphalt (RFA mixtures; the cement reinforced recycled foamed asphalt (CRFA mixtures; the semihot recycled foamed asphalt (SRFA mixtures; and recycled hot-mix asphalt (RHMA mixtures. It is found that the FRFA mixture shows higher Marshall stability than the RFA and SRFA mixtures, higher indirect tensile strength than the RFA mixture, and higher rut resistance than the RFA, SRFA, and RHMA mixtures as seen from the wheel tracking test.

  3. 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.

  4. APPLICATION OF LOW TEMPERATU RE PROPERTIES IMPROVEMENT ASPHALT TO REPAIRE WORK OF RO CK FILL DAM WITH ASPHALT FACING

    Science.gov (United States)

    Shimazaki, Masaru; Tsunoo, Takashi; Kasahara, Atsushi

    The low temperature properties improvement asphalt that is no decreasing the transformation follow and the stress relaxation properties at the low temperature was developed. It aimed at properties of PG64-28 (lowest temperature 28 degree C and maximum temperature 64 degree C that was able to be used) from PG (Performance Grade) of mix design method SUPERPAVE (Superior Performance Pavement) of new road-building plan SHRP (Strategic Highway Research Program) in the United States when developing. When the repair work of the rock fill dam with asphalt facing located in Kyogoku-cho Abuta-gun Hokkaido was planned, the applicability of the developed asphalt was verified. As for the verification outcome and the developed asphalt, it was proven that it was applied to the repair construction, and there was no problem in manufacturing and construction.

  5. Replacement of asphalt in glass-mat roofing shingles. Final report, March 1980-March 1982

    Energy Technology Data Exchange (ETDEWEB)

    Bastian, E.J. Jr.; McCandlish, E.F.K.; Sieling, F.W.

    1982-05-01

    Up to 50% of the asphalt now used in glass-mat shingles may be replaceable by increasing the mineral filler content and/or extending the asphalt with elemental sulfur. Highly filled, lab-made shingles containing asphalt flux perform acceptably in fire tests, slide tests, blister tests, granule adhesion, and freeze-thaw cracking tests. They have high stain and scuff potential and are too limp for convenient application around 110/sup 0/F. Lab-made shingles containing asphalt saturant are satisfactory in most respects, but they are still too limp for high temperature application. Various methods to stiffen highly filled shingles were tried. The most promising method is the use of two lightweight glass mats, laminated together with asphalt. Shingles made in this way have handling properties superior to conventional shingles and are economically feasible. In the area of replacement of asphalt with sulfur, five small-scale plant trials produced shingles which, after a year of outdoor exposure, are satisfactory. On the basis of preliminary measurements, no important difference in tensile or flexural properties between asphalt and sulfur/asphalt shingles is expected. In Weather-Ometer tests, sulfur/asphalt tends to have lower durability than conventional coating. This is confirmed by outside weathering of sulfur/asphalt films. By choosing the correct asphalt softening point and correct filler level, sulfur/asphalt/filler can have equal durability to conventional asphalt/filler combinations.

  6. [Appearance of aromatic polycyclic hydrocarbons during construction of asphalt and tar road surfaces].

    Science.gov (United States)

    Braszczyńska, Z; Osińska, R; Linscheid, D; Smolik, E

    1987-01-01

    The dust was sampled using personal samplers and stationary aspirators. PAHs were determined by thin layer chromatography and spectrophotometry in the UV and Vis range. In the samples the concentrations of coal tar pitch volatiles (benzene extract) and phenanthrene, fluoranthene, pyrene, chrysene, tetraphene, benzo(a)pyrene, benzo(e)pyrene, perylene, 1,12 benzoperylene, indeno(1,2,3-cd) pyrene were determined. The qualitative analysis identified all these hydrocarbons but only fluoranthene, pyrene, chrysene, tetraphene and benzo(a)pyrene could be quantitatively determined. The benzene extract concentration exceeds the value of 0.2 mg/m3 in 50% of samples. Much higher results were obtained for tar-concrete (1.45-2.85 mg/m3) than for asphalt-concrete (0.14-0.71 mg/m3). Also the drivers are exposed to excess benzene extract concentrations (0.055-0.669 mg/m3). Laboratory workers were found to be exposed to high concentrations of PAH and several solvents.

  7. Professionalising the asphalt construction process: aligning information technologies, operators' knowledge and laboratory practices

    NARCIS (Netherlands)

    Bijleveld, Frank Roland

    2015-01-01

    This research addresses the need to professionalise the asphalt construction process. A distinctive action research strategy is designed and carried out to progressively improve operational strategies of asphalt teams from technological, human (operator) and laboratory perspectives. Using informatio

  8. The Effect of Joint Width on Structural Performance of Asphalt Block Pavements

    Directory of Open Access Journals (Sweden)

    Ahmed Abdelgalil

    2014-02-01

    Full Text Available Asphalt blocks have been occasionally used around the world as a road pavement, but there have been very limited studies being done to evaluate the effect of joint width (spacing between the blocks on the structural performance of asphalt paving blocks. This study explains the experimental study to assess the performance and properties of asphalt paving blocks laid with different joint widths between the blocks i.e., 0, 2 and 3 mm, respectively. A total of 250 asphalt paving blocks was manufactured and tested in the laboratory to ascertain the density, air voids, the compressive strength and the rut depth and displacement occurred in asphalt paving block. The design compressive load of single asphalt paving block is 166 kN. The test results showed that the joint width plays a vital role on the performance of asphalt block pavement. Asphalt paving blocks were laid as closely in contact as possible (0 mm yields the best structural performance.

  9. The road that's taken : Alberta's bitumen and the world of asphalt

    International Nuclear Information System (INIS)

    Approximately one third of the bitumen produced by the oil sands industry in Canada is used as asphalt in roads and roofing materials. Crude oils used for asphalt production require very little refining. The asphalt market has become a key profit centre for some Cold Lake operators. Imperial Oil has established a research centre devoted to asphalt production at its Sarnia-based refinery. A decline in heavy oil supplies from Mexico and Venezuela has left Canada with a larger margin of the asphalt market. Industry leaders predict that demand for asphalt products will grow by 2.6 per cent per year. A sharp increase in asphalt prices led to many construction delays in 2007. Trials are now being conducted on a new warm mix paving technology that allows users to lower the temperature of asphalt by 20 to 30 degrees C when paving. 2 figs

  10. Sustainable Concrete Technology

    Directory of Open Access Journals (Sweden)

    Sim J.

    2015-12-01

    Full Text Available The growing concern over global warming and significant ecological changes requires sustainable development in all fields of science and technology. Concrete not only consumes huge amount of energy and natural sources, but also emits large amount of CO2, mainly due to the production of cement. It is evident that such large amount of concrete production has put significant impact on the energy, resource, environment, and ecology of the society. Hence, how to develop the concrete technology in a sustainable way has become a significant issue. In this paper, some of Korean researches for sustainable development of concrete are presented. These are sustainable strengthening for deteriorated concrete structure, sustainable reinforcement of new concrete structure, sustainable concrete using recycled aggregate and supplementary cementing materials and finally application of each technique to precast concrete.

  11. Asphalt Roofing Shingles Into Energy Project Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    Jameson, Rex, PE

    2008-04-28

    Based on a widely cited September, 1999 report by the Vermont Agency of Natural Resources, nearly 11 million tons of asphalt roofing shingle wastes are produced in the United States each year. Recent data suggests that the total is made up of about 9.4 million tons from roofing tear-offs and about 1.6 million tons from manufacturing scrap. Developing beneficial uses for these materials would conserve natural resources, promote protection of the environment and strengthen the economy. This project explored the feasibility of using chipped asphalt shingle materials in cement manufacturing kilns and circulating fluidized bed (CFB) boilers. A method of enhancing the value of chipped shingle materials for use as fuel by removing certain fractions for use as substitute raw materials for the manufacture of new shingles was also explored. Procedures were developed to prevent asbestos containing materials from being processed at the chipping facilities, and the frequency of the occurrence of asbestos in residential roofing tear-off materials was evaluated. The economic feasibility of each potential use was evaluated based on experience gained during the project and on a review of the well established use of shingle materials in hot mix asphalt. This project demonstrated that chipped asphalt shingle materials can be suitable for use as fuel in circulating fluidized boilers and cement kilns. More experience would be necessary to determine the full benefits that could be derived and to discover long term effects, but no technical barriers to full scale commercial use of chipped asphalt shingle materials in these applications were discovered. While the technical feasibility of various options was demonstrated, only the use of asphalt shingle materials in hot mix asphalt applications is currently viable economically.

  12. Study on Process for Manufacturing Heavy Traffic Asphalt from Gudong Crude

    Institute of Scientific and Technical Information of China (English)

    Wang Zijun; Long Jun; She Yucheng

    2004-01-01

    The Gudong crude from Gudao oil-bearing region in the Shengli oilfield was used as the target for studying the process of manufacturing heavy traffic road asphalt. The heavy traffic road asphalt products can be made from Gudong crude through blending residuum from mild thermal conversion of vacuum resid with extract, blending the deoiled asphalt from VR propane deasphalting with vacuum resid and the extract, and blending of oxidizedhard asphalt originated from VR with the extract.

  13. Optimization of asphalt rubber hot mixes based on performance laboratory tests

    OpenAIRE

    Neto, Silvrano Adonias Dantas; Farias, Márcio Muniz de; Pais, Jorge C.; Pereira, Paulo A. A.

    2003-01-01

    Asphalt binders modified with crumb rubber recycled from ground tires have been successfully used in asphalt mixtures improving the mechanical and functional behaviour of the pavements. This paper shows the influence of several factors that affect the behaviour of asphalt-rubber (AR) and of hot mixes made with this material. Modified binders were prepared using a straight binder with 35/50 penetration and rubber obtained by the environmental process. Samples of asphalt-rubber w...

  14. Visualizing asphalt roller trajectories in context: acquiring, processing, and representing sensor readings

    OpenAIRE

    Vasenev, Alexandr Nikolajevitsj

    2015-01-01

    The asphalt compaction process relies heavily on the skills and knowledge of roller operators who act alongside other stakeholders involved in asphalt paving. It is essential that these construction specialists: (1) are adequately informed about the initial temperature distribution of the asphalt layer – an essential context factor of asphalt compaction; and (2) have the possibility to improve their knowledge by reflecting on the already-conducted and alternative compaction strategies. Both t...

  15. SGC Tests for Influence of Material Composition on Compaction Characteristic of Asphalt Mixtures

    OpenAIRE

    Qun Chen; Yuzhi Li

    2013-01-01

    Compaction characteristic of the surface layer asphalt mixture (13-type gradation mixture) was studied using Superpave gyratory compactor (SGC) simulative compaction tests. Based on analysis of densification curve of gyratory compaction, influence rules of the contents of mineral aggregates of all sizes and asphalt on compaction characteristic of asphalt mixtures were obtained. SGC Tests show that, for the mixture with a bigger content of asphalt, its density increases faster, that there is a...

  16. Design of open graded friction courses with sulfur extended asphalt binders

    Science.gov (United States)

    Saylak, D.; Ho, K. K.; Gallaway, B. M.; Little, D. N.

    1982-09-01

    The combination of the anticipated shortage of asphalt cement and the projected abundance of sulfur has led to the investigation of the potential for substituting this element for the former in the paving industry. Sulfur was incorporated with asphalt to form sulfur-extended asphalt (SEA) binders for use in open graded friction course mixtures. The experimental design variable included aggregated type, asphalt cement, level of sulfur contents in the binder and method of preparing SEA binders.

  17. concrete5 for developers

    CERN Document Server

    Uzayr, Sufyan bin

    2014-01-01

    Whether you have had some previous experience with concrete5 or are entirely new to it, this book will help you understand all that you need to know in order to get started with concrete5 development. A background in PHP is required; some knowledge of HTML/CSS is needed in order to fully grasp the concepts underlying concrete5 theme development.

  18. Deterioration of Concrete Structures

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    Chloride ingress is a common cause of deterioration of reinforced concrete bridges. Concrete may be exposed to chloride by seawater or de-icing salts. The chloride initiates corrosion of the reinforcement, which through expansion disrupts the concrete. In addition, the corrosion reduces the cross...

  19. Survey of microbial degradation of asphalts with notes on relationship to nuclear waste management

    International Nuclear Information System (INIS)

    A survey has been made of the microbial degradation of asphalts. Topics covered include chemical and physical properties of asphalts, their chemical stability, methods of demonstrating their microbial degradation, and environmental extremes for microbial activity based on existing literature. Specific concerns for the use of asphalt in nuclear waste management, plus potential effects and consequences thereof are discussed. 82 references

  20. 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.

  1. ASPHALT FOR OFF-STREET PAVING AND PLAY AREAS, 3RD EDITION.

    Science.gov (United States)

    Asphalt Inst., College Park, MD.

    THIS PAMPHLET DISCUSSES THE ALTERNATIVE METHODS, APPLICATIONS, AND TECHNICAL CONSIDERATIONS FOR OFF-STREET PAVING AND PLAY AREAS. OFF-STREET PAVING INCLUDES--(1) ASPHALT-PAVED PARKING AREAS, (2) ROOF DECK PARKING AREAS, (3) ASPHALT-PAVED DRIVEWAYS, (4) ASPHALT-PAVED SERVICE STATION LOTS, AND (5) SIDEWALKS. THE DISCUSSION OF PLAY AREAS…

  2. 40 CFR Table 2 of Subpart Aaaaaaa... - Emission Limits for Asphalt Roofing Manufacturing (Coating) Operations

    Science.gov (United States)

    2010-07-01

    ... Manufacturing (Coating) Operations 2 Table 2 of Subpart AAAAAAA of Part 63 Protection of Environment... Pollutants for Area Sources: Asphalt Processing and Asphalt Roofing Manufacturing Other Requirements and... AAAAAAA of Part 63—Emission Limits for Asphalt Roofing Manufacturing (Coating) Operations For * * *...

  3. Image analysis of aggregate,mastic and air void phases for asphalt mixture%Image analysis of aggregate, mastic and air void phases for asphalt mixture

    Institute of Scientific and Technical Information of China (English)

    ADHIKARI Sanjeev; YOU Zhan-ping; HAO Pei-wen; WANG Hai-nian

    2013-01-01

    The shape characterization and spatial distribution of aggregate,mastic and air void phases for asphalt mixture were analyzed.Three air void percentage asphalt mixtures,4%,7% and 8%,respectively,were cut into cross sections and polished.X-ray scanning microscope was used to capture aggregate,mastic,air void phase by the image.The average of polygon diameter was chosen as a threshold to determine which aggregates would be retained on a given sieve.The aggregate morphological image from scanned image was utilized by digital image processing method to calculate the gradation of aggregate and simulate the real gradation.Analysis result shows that the air void of asphalt mixture has influence on the correlation between calculation gradation and actual gradation.When comparing 4.75 mm sieve size of 4%,7% and 8% air void asphalt mixtures,7% air void asphalt mixture has 55% higher than actual size gradation,8% air void asphalt mixture has 8% higher than actual size gradation,and 4% air void asphalt mixture has 3.71% lower than actual size gradation.4% air void asphalt mixture has the best correlation between calculation gradation and actual gradation comparing to other specimens.The air void percentage of asphalt mixture has no obvious influence on the air void orientation,and three asphalt mixtures show the similar air orientation along the same direction.4 tabs,7 figs,17 refs.

  4. UTILIZATION OF WASTE PLASTIC BOTTLES IN ASPHALT MIXTURE

    Directory of Open Access Journals (Sweden)

    TAHER BAGHAEE MOGHADDAM

    2013-06-01

    Full Text Available Nowadays, large amounts of waste materials are being produced in the world. One of the waste materials is plastic bottle. Generating disposable plastic bottles is becoming a major problem in many countries. Using waste plastic as a secondary material in construction projects would be a solution to overcome the crisis of producing large amount of waste plastics in one hand and improving the structure’s characteristics such as resistance against cracking on the other hand. This study aimed to investigate the effects of adding plastic bottles in road pavement. Marshall properties as well as specific gravity of asphalt mixture containing different percentages of plastic bottles were evaluated. Besides, Optimum Asphalt Content (OAC was calculated for each percentages of plastic bottles used in the mix. The stiffness and fatigue characteristics of mixture were assessed at OAC value. Results showed that the stability and flow values of asphalt mixture increased by adding waste crushed plastic bottle into the asphalt mixture. Further, it was shown that the bulk specific gravity and stiffness of mixtures increased by adding lower amount of plastic bottles; however, adding higher amounts of plastic resulted in lower specific gravity and mix stiffness. In addition, it was concluded that the mixtures containing waste plastic bottles have lower OAC values compared to the conventional mixture, and this may reduce the amount of asphalt binder can be used in road construction projects. Besides, the mixtures containing waste plastic showed significantly greater fatigue resistance than the conventional mixture.

  5. Recovery and reuse of asphalt roofing waste. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Desai, S.; Graziano, G.; Shepherd, P.

    1984-02-02

    Burning of asphalt roofing waste as a fuel and incorporating asphalt roofing waste in bituminous paving were identified as the two outstanding resource recovery concepts out of ten studied. Four additional concepts might be worth considering under different market or technical circumstances. Another four concepts were rated as worth no further consideration at this time. This study of the recovery of the resource represented in asphalt roofing waste has identified the sources and quantities of roofing waste. About six million cubic yards of scrap roofing are generated annually in the United States, about 94% from removal of old roofing at the job site and the remainder from roofing material production at factories. Waste disposal is a growing problem for manufacturers and contractors. Nearly all roofing waste is hauled to landfills at a considerable expense to roofing contractors and manufacturers. Recovery of the roofing waste resource should require only a modest economic incentive. The asphalt contained in roofing waste represents an energy resource of more than 7 x 10/sup 13/ Btu/year. Another 1 x 10/sup 13/ Btu/year may be contained in field-applied asphalt on commercial building roofs. The two concepts recommended by this study appear to offer the broadest applicability, the most favorable economics, and the highest potential for near-term implementation to reuse this resource.

  6. Aging test results of an asphalt membrane liner

    International Nuclear Information System (INIS)

    The objective of the asphalt aging study described in this report was to determine the expected performance lifetime of a catalytically airblown asphalt membrane as a seepage barrier for inactive uranium mill tailings. The study, conducted by Pacific Northwest Laboratory for the Department of Energy's Uranium Mill Tailings Remedial Action Program, showed through chemical compatibility tests that the asphalt membrane is well suited for this purpose. The chemical compatibility tests were designed to accelerate the aging reactions in the asphalt and to determine the accelerated aging effect. Higher temperatures and oxygen concentrations proved to be effective acceleration parameters. By infrared spectral analysis, the asphalt was determined to have undergone 7 years of equivalent aging in a 3-month period when exposed to 400C and 1.7 atm oxygen pressure. However, the extent of aging was limited to a maximum penetration of 0.5% of the total liner thickness. It was concluded that the liner could be expected to be effective as a seepage barrier for at least 1000 years before the entire thickness of the liner would be degraded

  7. An Approach for Nonlinear Fatigue Damage Evaluation in Asphalt Pavements

    Science.gov (United States)

    Rajbongshi, Pabitra; Thongram, Sonika

    2016-08-01

    Fatigue due to vehicular loads is one of the primary distress mechanisms in asphalt pavements. It happens primarily due to deterioration in asphalt material with load repetitions. Degradation of asphalt material may be evaluated using different parameters. In view of degradation, the incremental damage in a given pavement section would be different for different repetitions, even with same loadings. Therefore, the damage progression becomes nonlinear with repetitions. Accounting such nonlinearity in damage accumulation, and based on different damage evaluation parameters, this paper presents an equivalent approach for fatigue damage evaluation in asphalt pavements. Traditional fatigue equation adopted in mechanistic-empirical pavement design has been used in the present work. Four different criteria, namely number of load repetitions, asphalt stiffness reduction, strain enhancement and fatigue life reduction with repetitions are considered for damage estimation. The proposed approach could estimate same value of nonlinear damage, irrespective of the criteria used. The simplest form of criterion i.e. the number of load repetitions can be used for fatigue performance evaluation. Probabilistically, the damage propagation is also correlated and assessed with the failure probability.

  8. Application of asphalt rubber technology to recreational trails

    Science.gov (United States)

    Ni, Haifeng

    Crumb rubber aggregate was employed instead of stone/sand aggregate in asphalt pavement that was modified by fine rubber particles. Crumb rubber aggregate forms an elastic network in the asphalt, which improves the pavement's susceptibility to low-temperature cracking, and absorb more stress at the crack tips than the conventional asphalt pavement. Laboratory tests were conducted to evaluate the tension/compression performance of a blend of asphalt rubber with rubber aggregate (ARRA). An optimum design methodology was introduced by examining the effect of asphalt source, curing temperature, curing time, rubber content, aggregate size, compaction pressure, and the effect of certain additives. At ambient temperature, the ARRA with equal amount of binder and aggregate exhibits good mechanical properties. Vestenamer helps improve the pavement's strength, stiffness, and fracture resistance to low temperature cracking. It was demonstrated that such pavement meets the mechanical requirements for recreational trails, such as bicycle, or pedestrian trails. ARRA is a viscoelastic material which exhibits time-dependent and loading rate-dependent behavior. Temperature is a key issue to its response to an external load. Both temperature and rate dependences were investigated. A series of uniaxial compression relaxation tests on ARRA or Vestenamer modified ARRA were conducted at room temperature to study the time-dependent performance of ARRA. Schapery's theory was applied to characterize the nonlinear viscoelastic behavior of ARRA.

  9. European experience with asphalt packaging of radioactive wastes

    International Nuclear Information System (INIS)

    In Europe, the use of asphalt is synonymous with volume reduction of low and medium level radioactive waste. It started at Marcoule, France in the early 1960's and soon was adopted by Karlsruhe in West Germany, Eurochemic in Belgium, and in other countries. The use of an asphalt (or bitumen) binder, or immobilizing agent, in the VRS (Volume Reduction and Solidification) process proved to be beneficial in many ways. At Karlsruhe, for example, the VRS asphalt system replaced a cement system (non-volume reducing) and resulted in two drums of solidified waste versus ten with cement. This process reduced the transportation problem considerably. Asphalt is an inert, waterproof material and provides significantly improved package integrity under all conditions of on-site storage, transportation, and burial. The asphalt VRS system provides considerable cost savings, particularly for the recurring items such as binder, containers, transportation, and burial. These annual savings may approach $500,000 annually for a 1000 MWe nuclear plant. End product advantages include higher resistance to leaching and other environmental impacts, as well as less internal corrosion of the drums

  10. Determination of Rheological Properties of Bio Mastic Asphalt

    Directory of Open Access Journals (Sweden)

    R. Muniandy

    2008-01-01

    Full Text Available Due to the high oil prices the price of asphalt binder has increased tremendously. This scenario has warranted demand for higher viscosity cheaper asphalt for pavement construction. A study was conducted to take advantage of the Empty Fruit Bunch (EFB of Date and Oil Palm trees (which are considered as waste to produce cellulose fiber to be used as additives in the asphalt binder. If these EFB's could be beneficially utilized in any application, it would reduce the load on the nation's landfills and at the same time reducing the cost of road construction. A total of 11 blends were prepared that consisted of 5 blends with date palm fiber, 5 blends with oil palm fiber and one control sample that contained no fibers. The samples were evaluated using Dynamic Shear Rheometer (DSR equipment in accordance with the superpave Strategic Highway Research Program (SHRP requirements. The neat asphalt binders (Unaged, Rolling Thin Film Oven (RTFO aged and Pressure Ageing Vessel (PAV samples were then measured for phase angle, shear strain and complex shear modulus and then evaluated in accordance with SHRP requirements. The results indicated that the fibers enhanced the rheological performance of Bio Mastic Asphalt (BMA blends. The control sample which was categorized as PG58 was enhanced to PG76 with 0.375% date palm fiber. The oil palm has also improved the blend up to PG70 with 0.3% oil palm fiber.

  11. Tetrapyrroles and associated compounds in Dead Sea asphalts

    Energy Technology Data Exchange (ETDEWEB)

    Aizenshtat, Z. (Hebrew Univ. of Jerusalem, Israel); Dinur, D.; Nissenbaum, A.

    1979-01-01

    Metallo- and free porphyrins (1000 to 1500 ppM) isolated from asphalts occurring as huge blocks floating in the northern part of the Dead Sea, have been analyzed by visible-uv (v-uv) spectrophotometry and by mass spectrometry. The concentration of vanadyl porphyrins in the asphalts exceeds by far that of the Ni-porphyrins, despite the l:3 V/Ni ratio found in the total asphalt sample. The free porphyrins resemble those from the Uinta Basin (USA) gilsonite and contain a mixture of homologous Aetio- and deoxyphyllo-erythroaetioporphyrins (DPEP). The non-porphyrin fraction of the asphalt showed an identical aliphatic, hydrocarbon distribution with that of heavy crude oil from the same area. The more polar fraction associated with the porphyrins was compared with the polar fraction of the previously described ozokerite from the Dead Sea area. From high-resolution MS, IR, v-uv and NMR spectra, combined with hydrolysis and GLC analysis, it is suggested that even-numbered (C/sub 12/, C/sub 16/, C/sub 18/, C/sub 18/ /sub 1/, C/sub 22/) fatty acids are associated with the asphaltic porphyrins, probably in the triglyceride form.

  12. 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.

  13. Autogenous Deformation of Concrete

    DEFF Research Database (Denmark)

    Autogenous deformation of concrete can be defined as the free deformation of sealed concrete at a constant temperature. A number of observed problems with early age cracking of high-performance concretes can be attributed to this phenomenon. During the last 10 years , this has led to an increased...... focus on autogenous deformation both within concrete practice and concrete research. Since 1996 the interest has been significant enough to hold international, yearly conferences entirely devoted to this subject. The papers in this publication were presented at two consecutive half-day sessions...... at the American Concrete Institute’s Fall Convention in Phoenix, Arizona, October 29, 2002. All papers have been reviewed according to ACI rules. This publication, as well as the sessions, was sponsored by ACI committee 236, Material Science of Concrete. The 12 presentations from 8 different countries indicate...

  14. Recycled Concrete as Aggregate for Structural Concrete Production

    OpenAIRE

    Mirjana Malešev; Vlastimir Radonjanin; Snežana Marinković

    2010-01-01

    A comparative analysis of the experimental results of the properties of fresh and hardened concrete with different replacement ratios of natural with recycled coarse aggregate is presented in the paper. Recycled aggregate was made by crushing the waste concrete of laboratory test cubes and precast concrete columns. Three types of concrete mixtures were tested: concrete made entirely with natural aggregate (NAC) as a control concrete and two types of concrete made with natural fine and recycle...

  15. Production of De-asphalted Oil and Fine Asphalt Particles by Supercritical Extraction

    Institute of Scientific and Technical Information of China (English)

    赵锁奇; 许志明; 王仁安

    2003-01-01

    A continuous three-stage supercritical fluid extraction (SFE) process with a capacity of 1.0kg.h-1 was setup to extract petroleum residue by pentane to obtain more oil for further upgrading. A discharging system integrated to the bottom of the extractor was used to recover solvent as gas while asphalt was obtained as fine particles. The influence of operating conditions on the yield and quality of extracts, i.e., deasphalted oil (DAO) and resin, was studied in the range of temperature 150-220℃, pressure of 4.0-6.0 MPa and the mass ratio of solvent to oil feed (S/O) 2.5-5.0. The particle size distribution, apparent forms and the packing density, which vary with operating pressure, were measured. The particle structures were observed by SEM as well. With the modification to conventional processes, furnace can be eliminated for solvent recovery from asphalt phase, so as to reduce energy consumption.

  16. A pulsed-and high resolution-NMR study of the asphalt compositions obtained by the composition analytical method

    International Nuclear Information System (INIS)

    12 Kinds of asphalts were fractionated by the usual composition analytical method to give asphaltenes, maltenes, and waxy substances. Their contents show fairly good relationships with softening temperatures, and 1/T2 values of asphalts. Pulsed- and high resolution-NMR measurements were made of the fractions of 8 asphalts out of 12 asphalts. Asphaltenes from all the asphalts were thought to have almost same structures and characters (T2 asymptotically equals μsec), and their contents vary with the asphalts. Maltenes had no characteristic structures owing to the imperfect fractionation employed in this study, and their content in the asphalt is the largest. (author)

  17. Increase of a Roadway Covering Durability by Using the Cement-Concrete Base Fragmented with the Geogrid

    Directory of Open Access Journals (Sweden)

    Sannikov Sergey

    2016-01-01

    Full Text Available Presents the results of studies of innovative materials in the field of in road construction. The paper presents an alternative method of increasing the cracking resistance of the roads asphalt-concrete pavement, constructed on the cement-concrete base, due to its fragmentation with the volumetric plastic geogrid while constructing. Theoretical, laboratory and field experimental studies of this design were conducted, as well as the effectiveness of the proposed solution was proved. The use of this design can improve the durability of the roadway coverings and reduce the costs for the roads repair and maintenance.

  18. 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

  19. Hanford Permanent Isolation Barrier Program: Asphalt technology test plan

    Energy Technology Data Exchange (ETDEWEB)

    Freeman, H.D.; Romine, R.A.

    1994-05-01

    The Hanford Permanent Isolation Barriers use engineered layers of natural materials to create an integrated structure with backup protective features. The objective of current designs is to develop a maintenance-free permanent barrier that isolates wastes for a minimum of 1000 years by limiting water drainage to near-zero amounts. Asphalt is being used as an impermeable water diversion layer to provide a redundant layer within the overall barrier design. Data on asphalt barrier properties in a buried environment are not available for the required 100-year time frame. The purpose of this test plan is to outline the activities planned to obtain data with which to estimate performance of the asphalt layers.

  20. Asphalt emulsion sealing of uranium mill tailings. 1980 annual report

    International Nuclear Information System (INIS)

    Studies of asphalt emulsion sealants conducted by the Pacific Northwest Laboratory have demonstrated that the sealants are effective in containing radon and other potentially hazardous material within uranium tailings. The laboratory and field studies have further demonstrated that radon exhalation from uranium tailings piles can be reduced by greater than 99% to near background levels. Field tests at the tailings pile in Grand Junction, Colorado, confirmed that an 8-cm admix seal containing 22 wt% asphalt could be effectively applied with a cold-mix paver. Other techniques were successfully tested, including a soil stabilizer and a hot, rubberized asphalt seal that was applied with a distributor truck. After the seals were applied and compacted, overburden was applied over the seal to protect the seal from ultraviolet degradation