WorldWideScience

Sample records for asphalt concrete

  1. VISCOELASTIC STRUCTURAL MODEL OF ASPHALT CONCRETE

    Directory of Open Access Journals (Sweden)

    V. Bogomolov

    2016-06-01

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

  2. 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.

  3. Steady-State Creep of Asphalt Concrete

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    Alibai Iskakbayev

    2017-02-01

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

  4. 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...

  5. 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.

  6. 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.

  7. 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

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

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    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.

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

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    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.

  10. Low permeability asphalt concrete gamma ray shielding properties.

    Science.gov (United States)

    Binney, S E; Sykes, K L

    1997-01-01

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

  11. 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...

  12. 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

  13. Crack repair of asphalt concrete with induction energy

    NARCIS (Netherlands)

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

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

  14. 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.

  15. DURABILITY OF ASPHALT CONCRETE MIXTURES USING DOLOMITE AGGREGATES

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    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.

  16. Induction Healing of Porous Asphalt Concrete

    NARCIS (Netherlands)

    Liu, Q.

    2012-01-01

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

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

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    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.

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

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    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.

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

    Science.gov (United States)

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

    2017-01-01

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

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

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    Yulia A. Ubas’kina

    2016-03-01

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

  1. 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.

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

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    Pan Pan

    2017-02-01

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

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

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    Erbol Tileuberdi

    2012-12-01

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

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

    OpenAIRE

    Tomlinson, Christopher

    2013-01-01

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

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

    OpenAIRE

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

    2012-01-01

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

  6. 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.

  7. 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…

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

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    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

  9. 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

  10. 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.

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

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    Jianmin Wu

    2014-12-01

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

  12. 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.

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

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    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 .

  14. 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 .

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

    Science.gov (United States)

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

    2011-10-30

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

  16. 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...

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

    OpenAIRE

    Khodary Moalla Hamed, Farag

    2010-01-01

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

  18. 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.

  19. 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.

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

    OpenAIRE

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

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    T. Sachet

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

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

    OpenAIRE

    Julide Oner; Burak Sengoz

    2015-01-01

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

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

    Science.gov (United States)

    Park, Philip

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

  4. 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.

  5. 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.

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

    Science.gov (United States)

    Ikpugha, Omo John

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

  7. 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.

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

    Directory of Open Access Journals (Sweden)

    Hasan Taherkhani

    2016-06-01

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

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

    NARCIS (Netherlands)

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

    2014-01-01

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

  10. 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

  11. 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

  12. 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.

  13. 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.

  14. 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.

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

    Directory of Open Access Journals (Sweden)

    Julide Oner

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

  16. 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.

  17. 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.

  18. Choosing mineral carrier of nanoscale additives for asphalt concrete

    Directory of Open Access Journals (Sweden)

    Inozemtsev Sergey Sergeevich

    2014-03-01

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

  19. 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.

  20. 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.

  1. Asphaltic Concrete Performance Under Heavy Fighter Aircraft Loading

    Science.gov (United States)

    1993-02-01

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

  2. 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.

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

    Institute of Scientific and Technical Information of China (English)

    高雪

    2013-01-01

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

  4. 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

  5. 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.

  6. 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.

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

    Directory of Open Access Journals (Sweden)

    Hasan Taherkhani

    2016-12-01

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

  8. 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.

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

    NARCIS (Netherlands)

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

    2013-01-01

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

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

    Science.gov (United States)

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

    2016-11-01

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

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

    Institute of Scientific and Technical Information of China (English)

    CHEN Jun; PAN Tongyan; HUANG Xiaoming

    2011-01-01

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

  12. 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

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

    Institute of Scientific and Technical Information of China (English)

    贾陇春

    2014-01-01

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

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

    OpenAIRE

    Hasan Taherkhani

    2016-01-01

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

  15. 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.

  16. 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。

  17. 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.

  18. 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.

  19. 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.

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

    Science.gov (United States)

    Ryden, N.; Park, C.B.

    2005-01-01

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

  1. 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.

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

    Institute of Scientific and Technical Information of China (English)

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

    2012-01-01

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

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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。

  8. 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.

  9. 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.

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

    Science.gov (United States)

    Ahmedzade, Perviz; Sengoz, Burak

    2009-06-15

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

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

    Science.gov (United States)

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

    2017-02-01

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

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

    Institute of Scientific and Technical Information of China (English)

    张昭; 李璐; 盛兴跃

    2012-01-01

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

  13. 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。

  14. 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.

  15. 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

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

    NARCIS (Netherlands)

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

    2014-01-01

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

  17. 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%.

  18. 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

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

    Institute of Scientific and Technical Information of China (English)

    谢盛

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Sebnem KARAHANCER

    2016-08-01

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

  1. 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。

  2. 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.

  3. 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

  4. 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%。

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

    Institute of Scientific and Technical Information of China (English)

    董苋伯; 吴进良

    2012-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    王磊

    2014-01-01

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

  7. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-07-01

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

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

    Institute of Scientific and Technical Information of China (English)

    钱振东; 孟凡奇; 曾靖

    2015-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    席晓彬

    2012-01-01

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

  11. 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.

  12. 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.

  13. 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.

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

    Institute of Scientific and Technical Information of China (English)

    李泽林

    2012-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Giyasov Botir Iminzhonovich

    2014-12-01

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

  16. 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。

  17. 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.

  18. 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.

  19. 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.

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

    Institute of Scientific and Technical Information of China (English)

    罗桑; 钱振东

    2012-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    陈俊; 黄晓明

    2012-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    崔晓波; 李超源; 邵强

    2014-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    张兴梅; 徐聪

    2015-01-01

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

  4. 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 ...

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

    Institute of Scientific and Technical Information of China (English)

    宋世德; 周卫杰

    2016-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    张丽娟

    2012-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    何文华; 郭韦韦; 杨群

    2012-01-01

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

  8. 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.

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

    Institute of Scientific and Technical Information of China (English)

    侯荣国; 牛开民; 田波

    2011-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    王强林

    2011-01-01

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

  11. 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。

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

    Institute of Scientific and Technical Information of China (English)

    张耀将

    2016-01-01

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

  13. 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.

  14. 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.

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

    Institute of Scientific and Technical Information of China (English)

    黄世静; 陈旭茜

    2014-01-01

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

  16. 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。

  17. 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.

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

    Institute of Scientific and Technical Information of China (English)

    韩树峰

    2013-01-01

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

  19. 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.

  20. 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。

  1. 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).

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

    Institute of Scientific and Technical Information of China (English)

    何娅兰

    2014-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    赵茜

    2012-01-01

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

  4. 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。

  5. 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.

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

    OpenAIRE

    Park, Taesoon; Lovell, C. W.

    1996-01-01

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

  7. 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…

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

    Institute of Scientific and Technical Information of China (English)

    赵前军; 潘红伟; 车小磊

    2012-01-01

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

  9. 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。

  10. 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.

  11. Concrete

    OpenAIRE

    2015-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    葛折圣

    2011-01-01

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

  13. 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.

  14. 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.

  15. 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…

  16. 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.

  17. 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

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

    Institute of Scientific and Technical Information of China (English)

    严应斌

    2012-01-01

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

  19. 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.

  20. 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.

  1. 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.

  2. 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...

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

    Institute of Scientific and Technical Information of China (English)

    王小兵

    2014-01-01

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

  4. 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.

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

    Directory of Open Access Journals (Sweden)

    Zhao Bing

    2015-05-01

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

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

    OpenAIRE

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

    2017-01-01

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

  7. Asphalt World

    OpenAIRE

    Bedwell, Simon A.

    2009-01-01

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

  8. Operational properties of nanomodified stone mastic asphalt

    Directory of Open Access Journals (Sweden)

    Inozemtsev Sergey Sergeevich

    2015-03-01

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

  9. 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.

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

    Institute of Scientific and Technical Information of China (English)

    曲旭光; 王建宇

    2014-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    王宏畅; 葛辉; 周明刚

    2016-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    张庆春

    2014-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    钱振东; 黄卫

    2003-01-01

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

  14. 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 .

  15. Mutagenicity of bitumen and asphalt fumes.

    Science.gov (United States)

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

    2003-08-01

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

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

    Institute of Scientific and Technical Information of China (English)

    向尚君; 石林; 廖佼

    2014-01-01

    为总结碾压式沥青混凝土心墙在高海拔地区的施工经验,以首次在西藏高海拔地区应用的西藏旁多水利枢纽大坝碾压式沥青混凝土心墙施工为例,从原材料、施工机械设备、沥青混合料施工配合比、沥青混合料拌和、沥青混凝土心墙施工方法、温度控制及防护措施等方面针对制约高海拔地区碾压式沥青混凝土心墙施工的主要问题进行了总结,指出高地震烈度、强紫外线辐射、深覆盖层、高寒等地质和气候特点是制约高海拔地区碾压式沥青混凝土心墙施工的主要问题,初步探寻出了加大沥青含量提高变形能力、采用帆布覆盖措施防止紫外线辐射、采取棉被和砂砾石覆盖措施进行保温等解决方法,并在旁多水利枢纽大坝碾压式沥青混凝土心墙施工中得到成功应用。%In order to summarize the construction experience of roller-compacted asphalt concrete core walls in high-altitude areas, the construction of core walls of the dams in the Pangduo Hydraulic Project, which were first used in the high-altitude area in Tibet, was taken as an instance. The construction technology for the roller-compacted hydraulic asphalt concrete cores in high-altitude areas is discussed, including raw materials, construction machinery and equipment, the construction mixing ratio of the asphalt mixture, the mixing technology of the asphalt mixture, construction methods of asphalt concrete core walls, temperature control and protective measures. It is concluded that geological and climatic characteristics such as high seismic intensity, strong ultraviolet radiation, deep overburden, and the extremely cold climate mainly affected the construction of roller-compacted asphalt concrete core walls in high-altitude areas. Methods to solve these problems are proposed, such as improving the deformation capacity by increasing the asphalt content, preventing ultraviolet radiation by using a

  17. 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.

  18. 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.

  19. Comparing Production and Placement of Warm-Mix Asphalt to Traditional Hot-Mix Asphalt for Constructing Airfield Pavements

    Science.gov (United States)

    2013-08-01

    pressure cells ( EPC ), single depth deflectometers (SDD), and asphalt strain gauges (ASG) are indicated by symbols denoted on the figures. Further...gauges, I-buttons, ASGs, SDDs, and EPCs to measure the pavement response to simulated aircraft loading. The asphalt concrete strain gauges (Figure 55...gauge in backscatter mode. The type of roller used for each pass is indicated on each figure. The contractor determined how many roller passes to use

  20. 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

  1. 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.

  2. 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.

  3. 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…

  4. 南京铁心桥钢桥面热拌环氧混凝土铺装工艺研究%Hot-mixing Epoxy Asphalt Concrete Pavement Technology for Steel BridgeDeck Pavement of Tiexin Bridge in Nanjing City

    Institute of Scientific and Technical Information of China (English)

    潘军; 杨文

    2016-01-01

    Based on the steel bridge deck pavement engineering of Tiexin bridge in Nanjing city,the pavement technologies of hot mixing epoxy asphalt concrete using on steel deck were studied,inclu-ding the pavement structure design,mix design,pavement performance evaluation and construction technology.The difference of pavement construction between hot mixing and warm mixing epoxy as-phalt were also introduced in this paper.Research results show that hot mixing epoxy asphalt is suit-able for steel deck pavement due to its high stability,excellent high temperature performance and con-venient workability.%结合南京铁心桥钢桥面环氧铺装实体工程,对热拌环氧沥青混凝土铺装结构形式、热拌环氧沥青性能与混合料配合比设计、路用性能评价,以及施工工艺进行了系统研究,全面比较了热、温拌环氧沥青铺装施工工艺的区别。结果表明,热拌环氧沥青混凝土具有高强度、出色的高温稳定性,以及便捷的施工可操作性,非常适用于大跨钢桥铺装工程。

  5. Aging of Asphalt Symposium, September 17th 2014, Delft, the Netherlands

    OpenAIRE

    Erkens, S.M.J.G.; Scarpas, A.; Blab, R.; Glaser, R; Glover, C.; Oeser, M.; Porot, L.; Soenen, H.

    2015-01-01

    Technical specifications for the asphalt concrete properties are developed to be able to specify mixtures that will perform well in pavement applications. Being able to identify and determine properties related to pavement performance in practice is crucial for both road authorities and contractors, since it allows for design and risk management by determining design life times and reliability. However, the properties of Asphalt Concrete (AC) change over its lifetime and since most pavement l...

  6. 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.

  7. 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

  8. Rutting Resistance of Asphalt Overlay with Multilayer Wheel Tracking Test

    Institute of Scientific and Technical Information of China (English)

    LIAO Weidong; CHEN Zheng; WU Shaopeng; MO Liantong; LIU Gang

    2006-01-01

    The rutting resistance of multilayer asphalt overlay was researched by using laboratory wheel tracking test. The effects of loading level and test temperature on rutting resistance of asphalt overlay structure were evaluated by means of multilayer specimens .In comparison with multilayer tests, standard specimens of various layers were also conducted to evaluate the rutting resistance. Experimental results indicated that the test temperature and applied load have a significant effect on rutting resistance of asphalt concrete. Higher test temperature and heavier applied load resulted in higher rut depths. In addition, the mutilayer wheel tracking test has been demonstrated to be a more reasonable solution in evaluation on rutting resistance of asphatt pavement structure beasuse it reflects the cumulative permanent deformation in all of asphalt layers.

  9. Mechanical evaluation of asphalt-aggregate mixtures prepared with fly ash as a filler replacement

    Energy Technology Data Exchange (ETDEWEB)

    Tapkin, T. [Anadolu Univ., Eskisehir (Turkey). Dept. of Civil Engineering

    2008-01-15

    This paper examined methods of introducing fly ash waste products as a filler in asphalt concrete mixtures. A literature review of studies involving fly ash and asphalts was conducted. The effect of fly ash filler replacements on the mechanical properties of asphalt-aggregate mixtures was investigated. A dense bituminous calcareous aggregate was used as a reference mixture for a series of tests. Three types of fly ash were investigated, notably (1) portland cement; (2) lime; and (3) control specimens. Changes in elastic strain, elastic modulus, and permanent strain properties of the asphalt mixtures were determined through a series of fatigue tests. The behaviour of the asphalt concrete pavements were analyzed under applied loads. Results of the tests showed that the fatigue life of the fly ash specimens was higher than the calcareous aggregate specimens. It was concluded that fly ash can used as a filler replacement for dense-graded wearing courses. 35 refs., 17 tabs., 8 figs.

  10. 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…

  11. 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...

  12. First Observation of the Blending Zone Morphology at the Interface of Reclaimed Asphalt Binder and Virgin Bitumen

    NARCIS (Netherlands)

    Nahar, S.N.; Mohajeri, M.; Schmets, A.J.M.; Scarpas, T.; Van de Ven, M.F.C.; Schitter, G.

    2013-01-01

    One of the challenges in designing recycled asphalt mixtures with a high amount of RAP is to estimate the blending degree between RAP binder and the added virgin bitumen. The extent of blending is crucial in this case as asphalt concrete response is influenced by the final binder properties. This pa

  13. Recent advances on self healing of concrete

    NARCIS (Netherlands)

    Schlangen, H.E.J.G.; Jonkers, H.M.; Qian, S.; Garcia, A.

    2010-01-01

    In this paper an overview is given of new developments obtained in research on self healing of cracks in cement based materials and asphalt concrete. At Delft University various projects are running to study self healing mechanisms. The first project that is discussed is Bacterial Concrete, in which

  14. 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.

  15. 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.

  16. 绿色环保型高性能沥青混凝土排水铺装用防水材料应用研究%Application research on the green high-performance waterproof material for asphalt concrete drainage pavement

    Institute of Scientific and Technical Information of China (English)

    杨冲; 冉千平; 孙德文

    2013-01-01

    This article introduces a high-performance resin-based waterproof materials for drainage pavement with asphalt con-crete,and its performance advantages as waterproof layer. Its excellent performance includes:4.07 MPa of adhesion to asphalt concrete base surface, 3.51 MPa of adhesion to the concrete surface, low temperature flexibility of up to -20℃,no impervious after 24 h under 1.8 MPa pressure, excellent abrasion resistance. It can not only achieve good compatibility between the waterproof layer with the substrate, but also avoid the economic losses due to performance deficiencies in the waterproof layer exist in the real project.%介绍了一种沥青混凝土排水铺装用的高性能树脂型防水材料以及其作为防水层所具备的性能优势.其优异性能表现在与沥青混凝土基面的粘结强度达4.07 MPa,与混凝土基面的粘结强度达3.51 MPa,低温弯折性可达-20℃,同时在1.8 MPa的压力下24 h不透水,耐磨性优良.不仅能够实现防水层与基层之间良好的相容性,同时避免了在实际工程中存在的因防水层性能缺陷带来的经济损失.

  17. 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

  18. 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

  19. 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.

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

    Directory of Open Access Journals (Sweden)

    HU Qiusheng

    2014-09-01

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

  1. 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.

  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. 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.

  5. 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.

  6. Dynamic Response Analysis of Asphalt Concrete Pavement with Permeable Base Considering Moving and Overload Effect of Vehicles%考虑车辆移动效应和超载的排水基层路面结构动力分析

    Institute of Scientific and Technical Information of China (English)

    欧金秋; 崔新壮; 王聪; 郑骁

    2011-01-01

    In order to study the dynamic response of asphalt concrete pavement with permeable base under vehicle loads, based fast Lagrangian finite difference method, the dynamic analysis of asphalt concrete pavement under various conditions is conducted, considering the influence of moving vehicle load and different speed. The results show that the pavement dynamic deflection did not increase though the modulus of permeable base is low. The permeable base reduced the dynamic stress at the bottom of the subbase, which can inhibit the cracking of reflection. With the increase of speed, both the dynamic deflection and stress decreased, so in high temperature season, low-speed vehicle can cause larger rutting. Little vehicle overload can induce larger dynamic deflection and stress thus causes larger pavement deformation even plastic damage and the cracking. It is implied that the governance of overload is of great significance for extending road life and reducing maintenance costs.%为了研究车辆荷载作用下排水基层路面的动力响应,同时考虑车速和轴载的影响,采用移动加载的方法,对不同工况下沥青混凝土路面进行了快速Lagrange有限差分分析.结果表明,路面弯沉并未因排水基层的低模量而增大,峰值甚至有所减小;排水基层的存在减小了底基层底部的动应力,可以抑制反射裂缝的产生;弯沉及动应力均随车速的增大而减小,高温季节,低速行驶更容易引起大车辙;当车辆超载50%时,弯沉和动应力均成倍增大,导致路面产生较大变形甚至塑性破坏,且更容易引起路面开裂,表明治理超载对延长道路使用寿命、降低养护成本具有重要意义.

  7. Polymer Blends Modified Asphalt

    Institute of Scientific and Technical Information of China (English)

    WANG YunPu; LI YuFeng; GAO XiaoHui; WANG RongMin

    2001-01-01

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

  8. 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

  9. 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

  10. Modeling Recycling Asphalt Pavement Processing Technologies in Asphalt Mixing Plants

    Directory of Open Access Journals (Sweden)

    Simonas Tamaliūnas

    2011-04-01

    Full Text Available The article presents reclaimed asphalt pavement (RAP processing technologies and equipment models used in the asphalt mixing plant (AMP. The schematic model indicating all possible ways to process RAP in AMP is shown. The model calculating the needed temperature of mineral materials used for heating RAP is given and an example of such calculation is provided.Article in Lithuanian

  11. 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.

  12. 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.

  13. 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,…

  14. 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,

  15. 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.  ……

  16. 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.

  17. Interaction nonlinearity in asphalt binders

    Science.gov (United States)

    Motamed, Arash; Bhasin, Amit; Liechti, Kenneth M.

    2012-05-01

    Asphalt mixtures are complex composites that comprise aggregate, asphalt binder, and air. Several research studies have shown that the mechanical behavior of the asphalt mixture is strongly influenced by the matrix, i.e. the asphalt binder. Characterization and a thorough understanding of the binder behavior is the first and crucial step towards developing an accurate constitutive model for the composite. Accurate constitutive models for the constituent materials are critical to ensure accurate performance predictions at a material and structural level using micromechanics. This paper presents the findings from a systematic investigation into the nature of the linear and nonlinear response of asphalt binders subjected to different types of loading using the Dynamic Shear Rheometer (DSR). Laboratory test data show that a compressive normal force is generated in an axially constrained specimen subjected to torsional shear. This paper investigates the source of this normal force and demonstrates that the asphalt binder can dilate when subjected to shear loads. This paper also presents the findings from a study conducted to investigate the source of the nonlinearity in the asphalt binder. Test results demonstrate that the application of cyclic shear loads results in the development of a normal force and a concomitant reduction in the dynamic shear modulus. This form of nonlinear response is referred to as an "interaction nonlinearity". A combination of experimental and analytical tools is used to demonstrate and verify the presence of this interaction nonlinearity in asphalt binders. The findings from this study highlight the importance of modeling the mechanical behavior of asphalt binders based on the overall stress state of the material.

  18. 75 FR 12988 - National Emission Standards for Hazardous Air Pollutants for Area Sources: Asphalt Processing and...

    Science.gov (United States)

    2010-03-18

    ... Sources: Asphalt Processing and Asphalt Roofing Manufacturing; Technical Correction AGENCY: Environmental... the asphalt processing and asphalt roofing manufacturing area source category (74 FR 63236). Following... the asphalt processing and asphalt roofing manufacturing area source category on December 2, 2009...

  19. Curing Behavior of Epoxy Asphalt

    Institute of Scientific and Technical Information of China (English)

    YU Jianying; CONG Peiliang; WU Shaopeng; CHENG Songbo

    2009-01-01

    The curing process of epoxy asphalt was analyzed by Fourier transform infrared (FT-IR)spectroscopy.Effect of curing temperature on viscosity of epoxy asphalt,and changes of mechanical properties with curing time were investigated.The evolution of concentration of epoxy band was followed as a function of the applied curing process.The experimental results indicate that the curing reaction rate of epoxy asphalt is invariable before 70 min at 120℃,and it decreases when curing time exceeds 70 min.The viscosity of epoxy asphalt increases slowly with curing time at initial curing stage.But it increases quickly after initial curing stage and the initial curing time decreases as the curing temperature increases.The tensile strength increases slowly at incipient curing stage and increases rapidly when curing time is form 20 min to 70 min.The elongation at break shows a decrease with curing time,but it exceeds 200%after cured.

  20. 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.

  1. Initiation and Propagation Mechanism of Blisters on the Epoxy Asphalt Concrete Paving Course of Steel Deck Bridge Pavement%钢桥面环氧沥青铺装层鼓泡形成扩展机理

    Institute of Scientific and Technical Information of China (English)

    张华; 郝培文; 张海伟

    2016-01-01

    In order to take effective steps to minimize the blistering problems on the epoxy asphalt overlays, the cause and propagation mechanism for blisters were studied systematically by means of field investigation, theoretical analysis and mathematical modeling. Based on the theory of thin plate and fracture mechanics,the deflection of blisters was studied under the pressure. Additionally, the energy principle in fracture mechanics was used to derive the energy relationship and the initiation and propagation mechanism was studied. The results indicate that the development of blisters includes three stages, namely, initiation, stale and unstable propagation. The deflection of blisters produced by the external force was related to the radius of blisters, depth and modulus of elasticity of pavement. The energy release rate was proposed as a criterion of the initiation and propagation of blisters. It provides the theory basis for further model experiment and simulation analysis.%为有效减少钢桥面环氧沥青铺装层出现鼓泡现象,采用现场调查、理论分析和数学建模的研究方法,系统地研究了鼓泡产生的原因和形成扩展机理。基于薄板理论,研究了鼓泡在竖向均布荷载作用下鼓泡挠度的变化规律。根据断裂力学中的能量原理,得到了鼓泡形成扩展过程中的能量关系,进而阐明了鼓泡形成扩展机理。研究结果表明:钢桥面环氧沥青铺装层鼓泡的形成扩展过程分为起裂、稳定扩展和失稳扩展3个阶段;鼓泡在外力作用下产生的挠度与鼓泡半径、铺装层厚度和弹性模量等因素有关,提出了以能量释放率为判定参数的扩展准则。

  2. 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.

  3. 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.

  4. 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.

  5. How Concrete is Concrete

    OpenAIRE

    2010-01-01

    If we want to make something concrete in mathematics education, we are inclined introduce, what we call, ‘manipulatives’, in the form of tactile objects or visual representations. If we want to make something concrete in a everyday-life conversation, we look for an example. In the former, we try to make a concrete model of our own, abstract, knowledge; in the latter, we try to find an example that the others will be familiar with. This article first looks at the tension between these tw...

  6. 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...

  7. 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。

  8. 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

  9. Analysis on durability of asphalt pavement%沥青路面耐久性分析

    Institute of Scientific and Technical Information of China (English)

    车守忠

    2011-01-01

    简要介绍了我国沥青混凝土路面使用现状,针对沥青路面的损坏问题进行了分析,分别阐述了影响沥青路面耐久性的内部因素和外部因素,从原材料、配合比、防水设计等方面入手提出了耐久性改善措施,以期指导实践。%This paper briefly introduced the current situation of asphalt concrete pavements in our country,according to the damage problems of asphalt pavement made analysis,elaborated separately the internal factors and external factors which affect the durability of asphalt pavement,put forward durability improvement measures from raw materials,mixing ratio,waterproof design and other aspects,in order to guide practice.

  10. 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.

  11. Analytical Study of the Wide Sleepers on Asphalt Trackbed in Consideration of Nonlinear Contact Condition

    Directory of Open Access Journals (Sweden)

    BuSeog Ju

    2013-08-01

    Full Text Available Recent years, domestic and international interest towards high-speed railway increases dramatically. As a consequence, researchers have shown interested on the track types and upper structure of railway too. Currently, generally used roadbed structure utilizes classical track. This structure has shown drawbacks including increased maintenance costs, train operation/run-ability at high speed, and decrease of passenger comfort. Therefore, many researches were conducted in order to overcome these challenges, by developing a concrete track structure, and asphalt trackbed system. The objective of current study was to evaluate the applicability of developed materials for an asphalt trackbed structure. Frictional force at the attached boundary between the developed asphalt materials and upperconcrete slab were assessed for performance evaluation. In the end, nonlinear contact model was developed, according to the result from performance evaluation. A wide sleeper for the actual asphalt trackbed was also designed using a developed non-linear attachment boundary model. Then, the structural safety evaluation was performed at HL-25 train load (the design load. In the case of HL-25 design load, RC wide sleepers showed a limitation on usability due to the tensile stress occurred in the lower part of the slab from the interaction with the asphalt trackbed. PC sleepers, with improved lower part tensile stress using a PC tendon, showed relatively stable structural behavior.

  12. Recombination of asphalt with bio-asphalt : binder formulation and asphalt mixes application

    OpenAIRE

    Peralta, J.; Williams, R. Christopher; Silva, Hugo Manuel Ribeiro Dias da; Machado, A. V.

    2014-01-01

    The bio-oil from fast pyrolysis is mainly produced using organic waste materials. This is a viscoelastic material, and after a heat treatment it has a viscosity and high/intermediate thermal rheological behavior similar to many types of asphalt used in the paving industry. These two characteristics show that this material could be a good alternative to replace asphalt. In order to improve the performance of bio-oil, it was hypothesized that the addition of crumb rubber would change the rheolo...

  13. 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.

  14. Permanent deformation of asphalt mixes

    NARCIS (Netherlands)

    Muraya, P.M.

    2007-01-01

    This dissertation describes the results of a research that was conducted on the permanent deformation of asphalt mixtures. Central to this research was the separate characterization of the contribution of the aggregate skeleton and the bituminous mortar towards resistance to permanent deformation. T

  15. 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.

  16. 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.

  17. Pervious Concrete

    OpenAIRE

    2012-01-01

    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...

  18. 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...

  19. 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.

  20. 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.

  1. 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.......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....

  2. Evaluation and Repair of Concrete Structures: Annotated Bibliography 1978 - 1988. Volume 2. (Repair, Evaluation, Maintenance and Rehabilitation Research Program)

    Science.gov (United States)

    1991-06-01

    term efficacy is not documented. D-154 "Demo-lition of the Old Aula Valley Bridge of the A7 Mortorway" (in Ger- man). 1981 (Feb). Beton und...The 10-in.-thick asphalt was repaired with an 8-in. concrete overlay. The KDOT decided to-mill off 4 in. of asphal- tic concrete and then place the 8

  3. 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。

  4. Assessment of Asphalt Concrete Reinforcement Grid in Flexible Pavements

    Science.gov (United States)

    2016-05-01

    consistently reached the maxi - mum 100 CBR, or the equivalent of a crushed limestone material. ERDC/CRREL TR-16-7 27 The depth of DCP penetration...appeared to be a weak correlation between the ISM value and the presence of grid reinforcement in the test sections. This relationship did not

  5. 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.

  6. 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....

  7. 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

  8. Pelletized Asphalt for Airfield Damage Repair

    Science.gov (United States)

    2009-08-01

    14, 2008. Gulf Asphalt Contractor (GAC), Panama City, FL, provided all labor , material (with the exception of pelletized asphalt) and equipment for...produced. Benefits include: reduced transportation, traffic disruption, operating costs, and labor costs, while increased productivity and... Mercado , E. A., A. Epps Martin, E. S. Park, C. Spiegelman, and C. J. Glover, “Factors Affecting Binder Properties between Production and Construction

  9. 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

  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. 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.

  12. Concrete structures

    CERN Document Server

    Setareh, Mehdi

    2017-01-01

    This revised, fully updated second edition covers the analysis, design, and construction of reinforced concrete structures from a real-world perspective. It examines different reinforced concrete elements such as slabs, beams, columns, foundations, basement and retaining walls and pre-stressed concrete incorporating the most up-to-date edition of the American Concrete Institute Code (ACI 318-14) requirements for the design of concrete structures. It includes a chapter on metric system in reinforced concrete design and construction. A new chapter on the design of formworks has been added which is of great value to students in the construction engineering programs along with practicing engineers and architects. This second edition also includes a new appendix with color images illustrating various concrete construction practices, and well-designed buildings. The ACI 318-14 constitutes the most extensive reorganization of the code in the past 40 years. References to the various sections of the ACI 318-14 are pro...

  13. 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...

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. Experimental testing of hot mix asphalt mixture made of recycled aggregates.

    Science.gov (United States)

    Rafi, Muhammad Masood; Qadir, Adnan; Siddiqui, Salman Hameed

    2011-12-01

    The migration of population towards big cities generates rapid construction activities. These activities not only put pressure on natural resources but also produce construction, renovation and demolition waste. There is an urgent need to find out ways to handle this waste owing to growing environmental concerns. This can reduce pressure on natural resources as well. This paper presents the results of experimental studies which were carried out on hot mix asphalt mixture samples. These samples were manufactured by adding recycled aggregates (RA) with natural crushed stone aggregates (CSA). Three levels of addition of RA were considered in the presented studies. RA were obtained from both the concrete waste of construction, renovation and demolition activities and reclaimed asphalt pavement. Separate samples were manufactured with the coarse and fine aggregate fractions of both types of RA. Samples made with CSA were used as control specimens. The samples were prepared and tested using the Marshall method. The performance of the samples was investigated in terms of density-void and stability/flow analysis and was compared with the performance criteria as given by National Highway Authority for wearing course material in Pakistan. Based on this data optimum asphalt contents were determined. All the samples made by adding up to 50% RA conform to the specification requirements of wearing course material as given by National Highway Authority in terms of optimum asphalt contents, voids in mineral aggregates and stability/flow. A statistical analysis of variation of these samples confirmed that addition is also possible statistically.

  19. 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...

  20. 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.

  1. 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.

  2. 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...

  3. 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

  4. 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.

  5. 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.

  6. Exposure to ultrafine particles in asphalt work.

    Science.gov (United States)

    Elihn, Karine; Ulvestad, Bente; Hetland, Siri; Wallen, Anna; Randem, Britt Grethe

    2008-12-01

    An epidemiologic study has demonstrated that asphalt workers show increased loss of lung function and an increase of biomarkers of inflammation over the asphalt paving season. The aim of this study was to investigate which possible agent(s) causes the inflammatory reaction, with emphasis on ultrafine particles. The workers' exposure to total dust, polycyclic aromatic hydrocarbons, and NO(2) was determined by personal sampling. Exposure to ultrafine particles was measured by means of particle counters and scanning mobility particle sizer mounted on a van following the paving machine. The fractions of organic and elemental carbon were determined. Asphalt paving workers were exposed to ultrafine particles with medium concentration of about 3.4 x 10(4)/cm(3). Ultrafine particles at the paving site originated mainly from asphalt paving activities and traffic exhaust; most seemed to originate from asphalt fumes. Oil mist exceeded occupational limits on some occasions. Diesel particulate matter was measured as elemental carbon, which was low, around 3 microg/m(3). NO(2) and total dust did not exceed limits. Asphalt pavers were exposed to relatively high concentrations of ultrafine particles throughout their working day, with possible adverse health effects.

  7. 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)

  8. 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.

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

    Directory of Open Access Journals (Sweden)

    Tao Ma

    2015-01-01

    Full Text Available 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, its inner structure and strength are much different from real aggregates. The strength of RAP has decisive effect on the strength of cold recycled asphalt mixture. New aggregates and fine gradation design can help improve the bonding between RAP and binder. For emulsified asphalt, slow setting of asphalt can give sufficient time for cement to hydrate which is helpful for strength formation in the cold recycled asphalt mixture. The high viscosity of asphalt can improve the early strength of cold recycled asphalt mixture that is important for traffic opening in the field. Cement is an efficient additive to improve the strength of cold recycled asphalt mixtures by promoting demulsification of emulsified asphalt and producing cement hydrates. However, the cement content is limited by RAP.

  10. Coprocessing Yanzhou coal with petroleum resid for preparing paving asphalt

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Z.; Li, Y.; Yang, J.; Liu, Z.; Chi, H. [Chinese Academy of Sciences, Taiyuan (China). State Key Laboratory of Coal Conversion

    2003-07-01

    Coprocessing Yanzhou coal with five types of petroleum resid for preparing high grade paving asphalt (HGPA) was investigated. The asphalt obtained was evaluated by 3 indexes: penetration, softening point and ductility. The thin layer chromatography (TLC) and NMR were used to characterise the asphalt. The results show that the properties of resid are crucial for the quality of asphalt. Under the experimental conditions, the resid with the lowest H/C ratio, highest aromatics content and shortest aliphatic side-chain produced asphalt with required quality for high grade paving asphalt used in China. Asphalt yield increased with H{sub 2} pressure and the quality of asphalt decreased with coal to resid ratio. 15 refs., 1 fig., 8 tabs.

  11. Photocatalyticpaving concrete

    OpenAIRE

    2014-01-01

    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 t...

  12. 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.

  13. 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.

  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. 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,…

  16. 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.

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

    OpenAIRE

    Pérez, F.; Rodriguez, M; 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...

  18. 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.

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

    Directory of Open Access Journals (Sweden)

    M. Pasetto

    2016-01-01

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

  20. 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.

  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. 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.

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

    NARCIS (Netherlands)

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

    2014-01-01

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

  5. Comparative Study of Asphalt Layer Temperature Field of Combined Type Pavement and Asphalt Pavement with Semi -Rigid Base Course%复合式路面与半刚性基层沥青路面的沥青层温度场对比研究

    Institute of Scientific and Technical Information of China (English)

    王锐

    2012-01-01

    The comparative Study of asphalt layer temperature field of combined type pavement and asphalt pavement with semi -rigid base course could provide support for design and construction of asphalt layer of com- bined type pavement or "change white to black" pavement (paving asphalt surface on old cement concrete pave- ment). Taking the asphalt layer as 2 -3 layers with not totally same thickness and material, each layer is studied and analyzed one after one. The result shows that the temperature field of asphalt layer of the two pavement struc- ture is very similar and the design and construction of asphalt layer of combined type pavement affected by tempera- ture could take that of asphalt pavement with semi - rigid base course as a reference.%通过对复合式路面与半刚性基层沥青路面的沥青层温度场对比研究,可为复合式路面或"白改黑"路面(旧水泥混凝土路面加铺沥青面层)沥青层的设计及施工提供技术支持。将沥青层看作是厚度和材料不全相同的2~3层,然后逐层研究分析,结果表明两种路面结构沥青层的温度场非常相似,认为温度作用下复合式路面沥青层的设计及施工经验可借鉴半刚性基层沥青路面。

  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. 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.

  8. Pneumoproteins and inflammatory biomarkers in asphalt pavers.

    Science.gov (United States)

    Ellingsen, Dag G; Ulvestad, Bente; Andersson, Lena; Barregard, Lars

    2010-09-01

    Pneumoproteins, biomarkers of systemic inflammation and endothelial activation were studied across a season in 72 asphalt pavers, 32 asphalt plant operators and 19 asphalt engineers. Smokers had lower concentrations of Clara cell protein (CC-16) and surfactant protein A, but higher concentrations of surfactant protein D, interleukin 6, C-reactive protein, fibrinogen and intercellular adhesion molecule (ICAM)-1 than non-smokers. Smokers reporting wheezing had lower mean CC-16 concentration than smokers not reporting wheezing (5.7 vs 8.6 microg l(-1); p = 0.05). Cholesterol, P-selectin and ICAM-1 were lower in pavers and operators at the end compared with the start of the season. This may be related to increased physical activity during the season.

  9. Thiol/disulfide homeostasis in asphalt workers.

    Science.gov (United States)

    Yilmaz, Ömer Hınç; Bal, Ceylan; Neşelioglu, Salim; Büyükşekerci, Murat; Gündüzöz, Meşide; Eren, Funda; Tutkun, Lutfiye; Yilmaz, Fatma Meric

    2016-09-02

    The aim of this study was to investigate thiol/disulfide homeostasis in asphalt workers who are exposed to polycyclic aromatic hydrocarbons occupationally. The study was carried out in 34 nonsmoker asphalt workers. Additionally, 35 healthy nonsmoker volunteers were recruited as control group. Thiol and disulfide concentrations were determined using the novel automated measurement method. Levels of urinary 1-OH-pyrene were analyzed by liquid chromatography. Disulfide/thiol ratio was significantly higher in exposed group (p = .034). Also, a positive correlation was detected between disulfide/thiol ratio and 1-OH-pyrene values (r = .249, p = .036). Thiol/disulfide homeostasis was found to be disturbed in asphalt workers. The novel test used in this study may be useful for evaluating the oxidative status in polycyclic aromatic hydrocarbon (PAH) exposure.

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

    Science.gov (United States)

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

    2008-05-31

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

  11. Characteristics of asphalt mixes with FT additive

    Science.gov (United States)

    Štefunková, S.

    2012-03-01

    This article is focused on low-temperature asphalt mixture technologies using FT additive and RAP. The modern production and use of asphalt mixture technologies with reduced temperatures has many advantages. These advantages mainly help to save energy and the environment. Lower temperatures enable a reduction in energy consumption, a more acceptable working environment for workers, a reduction in negative environmental effects, such as greenhouse gas emissions, and an improvement in the workability of mixtures and a prolongation of their duration. This technology is currently becoming popular in many countries.

  12. 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...

  13. 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.

  14. 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.

  15. 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.

  16. 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 10(7) 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.

  17. Finite element simulation of asphalt fatigue testing

    DEFF Research Database (Denmark)

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

    1997-01-01

    The traditional interpretation of fatigue tests on asphalt mixes has been in terms of a logarithmic linear relationship between the constant stress or strain amplitude and the number of load repetitions to cause failure, often defined as a decrease in modulus to half the initial value. To accomod......The traditional interpretation of fatigue tests on asphalt mixes has been in terms of a logarithmic linear relationship between the constant stress or strain amplitude and the number of load repetitions to cause failure, often defined as a decrease in modulus to half the initial value....... To accomodate non-constant stress or strain, a mode factor may be introduced or the dissipated energy may be used instead of stress or strain.Cracking of asphalt (or other materials) may be described as a process consisting of three phases. In phase one diffuse microcracking is formed in the material...... 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...

  18. The use of asphalt in hydraulic engineering

    NARCIS (Netherlands)

    Van de Velde, P.A.; Ebbens, E.H.; Van Herpen, J.A.

    1985-01-01

    Asphalt products have been used in the Netherlands in hydraulic engineering for a long time on a large scale, especially after the great disaster in 1953 when a large part of western Holland was flooded by the sea. After the disaster a great number of dikes had to be repaired very quickly and this w

  19. 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.

  20. High Performance Concrete

    OpenAIRE

    Traian Oneţ

    2009-01-01

    The paper presents the last studies and researches accomplished in Cluj-Napoca related to high performance concrete, high strength concrete and self compacting concrete. The purpose of this paper is to raid upon the advantages and inconveniences when a particular concrete type is used. Two concrete recipes are presented, namely for the concrete used in rigid pavement for roads and another one for self-compacting concrete.

  1. Concrete spirituality

    OpenAIRE

    2014-01-01

    This article reflects on a number of liturgical innovations in the worship of Melodi ya Tshwane, an inner-city congregation of the Uniting Reformed Church in Southern Africa (URCSA). The focus of the innovations was to implement the understanding of justice in Article 4 of the Confession of Belhar, a confessional standard of the URCSA. The basic contention of the article is that well designed liturgies that facilitate experiences of beauty can nurture a concrete spirituality to mobilise urba...

  2. 浅谈沥青拌和楼使用和维修中应注意的问题%The Notices of Asphalt Mixing Plant in Use and Repair

    Institute of Scientific and Technical Information of China (English)

    张仁勇

    2013-01-01

    随着国家经济的高速发展,我国道路交通设施也在不断改善中。由于沥青混凝土被广泛使用,因此沥青拌和楼这一生产沥青混凝土的设备也在日趋完备。本文指出了沥青拌和楼在工作过程中常见的问题,并对其使用和维修中应注意的问题进行了分析,希望能令沥青拌和楼更加完善。%With the rapid development of the national econo-my, our country road traffic facilities are also improvements in. The asphalt concrete is widely used, so the production equipm-ent of asphalt concrete, the asphalt mixing plant is more and more complete. The paper points out that the asphalt mixing p-lant common problems in work, analyzes issues which should be pay at ention to in the use and repair, hopes can help asphalt mixing building more perfect.

  3. Mechanical properties of gutta-percha sulfide modified asphalt

    Science.gov (United States)

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

    2017-01-01

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

  4. 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.

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

    Science.gov (United States)

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

    2014-01-01

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

  7. Detection of asphalt pavement cracks using remote sensing techniques

    Science.gov (United States)

    Mettas, Christodoulos; Agapiou, Athos; Themistocleous, Kyriacos; Neocleous, Kyriacos; Hadjimitsis, Diofantos G.

    2016-10-01

    Deterioration of asphalt road pavements is inevitable throughout its life cycle. There are several types of deterioration that take place on these surfaces, like surface defects and deformations. One of the most common asphalt defects is cracking. Fatigue, transverse, longitudinal, reflective, edge, block and slippage are types of cracking that can be observed anywhere in the world. Monitoring and preventative/periodic maintenance of these types of wears are two very important actions that have to take place to avoid "costly" solutions. This paper aims to introduce the spectral characteristics of uncracked (healthy) and cracked asphalt surfaces which can give a new asphalt crack index. This is performed through remote sensing applications in the area of asphalt pavements. Multispectral images can be elaborated using the index to enhance crack marks on asphalt surfaces. Ground spectral signatures were acquired from both uncracked and cracked asphalted areas of Cyprus (Limassol). Evaluation separability indices can be used to identify the optimum wavelength regions that can distinguish better the uncracked and cracked asphalt surfaces. The results revealed that the spectral sensitivity for the enhancement of cracked asphalt was detected using the Euclidean, Mahalanobis and Cosine Distance Indices in the Vis range (approximately at 450 nm) and in the SWIR 1 range (approximately at 1750 nm).

  8. 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.

  9. 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.

  10. Quick concrete

    OpenAIRE

    Olaya Beracasa, Santiago Eduardo; Flórez Gutiérrez, Richard Daniel

    2016-01-01

    QUICK CONCRETE es un emprendimiento el cual se planteó como una empresa prestadora de servicios en el sector de la construcción en la ciudad de Ibagué, Colombia. Con ayuda de empresas ya reconocidas a nivel regional como lo son: la distribuidora de materiales y ferretería La Española, A&C y la ladrillera Ladrillos Roma. Se espera impactar en el mercado con un método diferente y un precio competitivo de servicio. El mayor impulso de la construcción puede estar asociado a una mayor demanda de v...

  11. 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.

  12. 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.

  13. Properties of concrete containing scrap-tire rubber--an overview.

    Science.gov (United States)

    Siddique, Rafat; Naik, Tarun R

    2004-01-01

    Solid waste management is one of the major environmental concerns in the United States. Over 5 billion tons of non-hazardous solid waste materials are generated in USA each year. Of these, more than 270 million scrap-tires (approximately 3.6 million tons) are generated each year. In addition to this, about 300 million scrap-tires have been stockpiled. Several studies have been carried out to reuse scrap-tires in a variety of rubber and plastic products, incineration for production of electricity, or as fuel for cement kilns, as well as in asphalt concrete. Studies show that workable rubberized concrete mixtures can be made with scrap-tire rubber. This paper presents an overview of some of the research published regarding the use of scrap-tires in portland cement concrete. The benefits of using magnesium oxychloride cement as a binder for rubberized concrete mixtures are also presented. The paper details the likely uses of rubberized concrete.

  14. Experiment Research on Freeze-thaw Splitting of Asphalt Concrete of Deicing and Snow Melting Based on Ground-Source Heat Pump%地源热泵融雪化冰沥青混凝土冻融劈裂实验研究

    Institute of Scientific and Technical Information of China (English)

    杨豪; 屠艳平; 朱志刚

    2016-01-01

    The technology of deicing and snow melting based on ground-source heat pump has many advantages, but some scholars pointed out that water damage was intensified because of deicing and snow melting. An experimental program was designed to estimate the degree of water damage of deicing and snow melting based on ground-source heat pump. The tensile splitting strength based on ground-source heat pump is 0.72MPa,but the tensile splitting strength of based on test procedures is 0.68MPa. The results showed that deicing and snow melting technology based on ground-source heat pump not only will increase the water damage of asphalt pavement, but also will improve the capability of resistance to water.%地源热泵融雪化冰技术具有许多优越性,有的学者指出道路融雪化冰会导致沥青路面水损害加剧。通过设计一套试验方案来评价利用地热源泵融雪化冰后路面的水损坏程度。地源热泵加热融化的试件的劈裂抗拉强度为0.72MPa,而根据试验规程测得的劈裂抗拉强度为0.68M孕a,结果表明地源热泵融雪化冰技术不仅不会增加沥青路面的水损害,还会提高路面抗水损害性能。

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

    OpenAIRE

    Mohd Rosli Mohd Hasan; Zhanping You

    2016-01-01

    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 f...

  16. Effect of cracking and randomness of inputs on corrosion initiation of reinforced concrete bridge decks exposed to chlorides

    Directory of Open Access Journals (Sweden)

    P. Konecny

    2017-01-01

    Full Text Available The paper is aimed at the indicative evaluation of the effect of random scatter of input parameters in case of durability of reinforced concrete bridge deck. The time to onset of corrosion of steel reinforcement of concrete bridge deck exposed to chloride is evaluated. The effect of cracking in concrete onto chloride ingress is considered. The selected steel reinforcement protection strategies are: unprotected steel reinforcement, epoxy-coated steel reinforcement and water-proof barrier bellow asphalt overlay. The preliminary model for damage effect on chloride ion ingress through water proof membrane under penetrable asphalt overlay is used. 2-D finite element chloride ingress model is combined with Monte Carlo simulation technique. The innovative crack effect modeling via highly penetrable elements is applied. Deterministic and probabilistic calculations are compared.

  17. 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

  18. 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

  19. 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.

  20. Stabilization/solidification of munition destruction waste by asphalt emulsion.

    Science.gov (United States)

    Cervinkova, Marketa; Vondruska, Milan; Bednarik, Vratislav; Pazdera, Antonin

    2007-04-02

    Destruction of discarded military munitions in an explosion chamber produces two fractions of hazardous solid waste. The first one is scrap waste that remains in the chamber after explosion; the second one is fine dust waste, which is trapped on filters of gas products that are exhausted from the chamber after explosion. The technique of stabilization/solidification of the scrap waste by asphalt emulsion is described in this paper. The technique consists of simple mixing of the waste with anionic asphalt emulsion, or two-step mixing of the waste with cationic asphalt emulsion. These techniques are easy to use and the stabilized scrap waste proves low leachability of contained heavy metals assessed by TCLP test. Hence, it is possible to landfill the scrap waste stabilized by asphalt emulsion. If the dust waste, which has large specific surface, is stabilized by asphalt emulsion, it is not fully encapsulated; the results of the leaching tests do not meet the regulatory levels. However, the dust waste solidified by asphalt emulsion can be deposited into an asphalted disposal site of the landfill. The asphalt walls of the disposal site represent an efficient secondary barrier against pollutant release.

  1. 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

  2. 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.

  3. 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....

  4. 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...

  5. 40 CFR Table 1 of Subpart Aaaaaaa... - Emission Limits for Asphalt Processing (Refining) Operations

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 14 2010-07-01 2010-07-01 false Emission Limits for Asphalt Processing... Area Sources: Asphalt Processing and Asphalt Roofing Manufacturing Other Requirements and Information... of Part 63—Emission Limits for Asphalt Processing (Refining) Operations For * * * You must meet...

  6. 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...

  7. Thermal Conduction and Insulation Modification in Asphalt-Based Composites

    Institute of Scientific and Technical Information of China (English)

    Xiaofeng Zhou; Shengyue Wang; Chao Zhou

    2012-01-01

    The relationship between thermal conductivity and properties of mixing particles is required for quantitative study of heat transfer processes in asphalt-based materials. In this paper, we measured the e?ective ther- mal conductivity of asphalt-based materials with thermal conduction (graphite) and insulation (cenosphere) powders modification. By taking account of the particle shape, volume fraction, the thermal conductivity of filling particles and base asphalt, we present a new differential effective medium formula to predict the thermal conductivity modification in asphalt-based composite. Our theoretical predications are in good agreement with the experiment data. The new model can be applied for predicting the thermal properties of asphalt-based mixture, which is available for most of thermal modification in two-phase composites.

  8. 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.

  9. 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.

  10. 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.

  11. 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。

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Laboratory Investigation of Fatigue Characteristics of Asphalt Mixtures with Steel Slag Aggregates

    Directory of Open Access Journals (Sweden)

    Hassan Ziari

    2015-01-01

    Full Text Available There are many steel-manufacturing factories in Iran. All of their byproducts, steel slag, are dumped randomly in open areas, causing many environmentally hazardous problems. This research is intended to study the effectiveness of using steel slag aggregate (SSA in improving the engineering properties, especially fatigue life of Asphalt Concrete (AC produced with steel slag. The research started by evaluating the physical properties of the steel slag aggregate. Then the 13 types of mixes which contain steel slag in portion of fine aggregates or in portion of coarse aggregates or in all portions of aggregates were tested. The effectiveness of the SSA was judged by the improvement in Marshall stability, indirect tensile strength, resilient modulus, and fatigue life of the AC samples. It was found that replacing the 50% of the limestone coarse or fine aggregate by SSA improved the mechanical properties of the AC mixes.

  17. 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.

  18. 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.

  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. 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.

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. Construction Technology Essentials for Drainage layer of Asphalt Stabilized Crushed Stone%沥青稳定碎石排水层施工技术要点

    Institute of Scientific and Technical Information of China (English)

    郑木莲; 彭磊; 马海淋

    2012-01-01

    To reduce the early water damage of asphalt concrete pavement, it is necessary to set the asphalt treated permeable base in the pavement structure and improve the ability of ruling out free water in the internal road. Compared with the foreign porous asphalt mixture gradation, the graduation range which is suitable for China engineering is determined, and the engineering graduation of asphalt treated permeable based on the Hua-Xin Expressway is designed. By figuring out the mine material surface area and oil film thickness to estimate the asphalt-aggregate ratio, combined with the leak test analysis and using Marshall stability test, pore ratio, bulk volume density, the optimal asphalt-aggregate ratio is eventually determined. The target and construction proportion of asphalt treated permeable are determined by the analysis of its properties and combination of the engineering practice. According to the type of asphalt treated permeable and comparison with the conventional structure of the asphalt concrete pavement, loose paving coefficient and compaction technology which fit asphalt treated permeable are formulated. The rationality of mix proportion, construction technology and the key point of construction control are verified by the construction quality examination.%为减少沥青混凝土路面早期水损害,在路面结构中设置沥青稳定碎石排水层,提高排除进入路面结构内部自由水的能力.对比国外排水沥青混合料的级配,确定适合我国工程运用的级配范围,依托化新高速公路实体工程,设计出沥青稳定碎石的工程级配.通过矿料表面积与油膜厚度估算油石比,结合析漏试验,运用马歇尔试验稳定度、空隙率、毛体积密度等最终确定最佳油石比.分析沥青稳定碎石混合料的特性,结合工程实践,确定沥青稳定碎石的目标配合比和施工配合比.根据沥青稳定碎石排水层的结构形式,对比常规沥青混凝土路面结构,制定符合

  6. 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。

  7. Recycling of demolished concrete

    Energy Technology Data Exchange (ETDEWEB)

    Nagataki, S. [Niigata Univ., Niigata (Japan). Dept. of Civil Engineering; Iida, K. [Technology Centre of Taisei Corp., Yokohama (Japan)

    2001-07-01

    There is a significant amount of research being conducted in Japan on ways to recycle demolished concrete. The material is already being used for road bases and foundations, but in the future, the concrete will have to be recycled as concrete aggregate. Recycling may also include the cement in the concrete in order to address the issue of global warming and carbon dioxide reductions. This initiative is in response to predictions that in the future there will be tremendous quantities of demolished concrete to deal with. Recycling of cement is also necessary in terms of resolving environmental problems and promoting sustainable development. The properties of concrete made with recycled aggregates were described and were compared with original concrete made of known materials. The paper also proposed an approach that should be taken to recycling concrete in the twenty-first century in which reduced limestone was used to reclaim cement. Recycled concrete with cement requires more energy, but uses less resources and discharges less carbon dioxide. Currently, recycled aggregate does not meet the Japanese Industrial Standard for concrete aggregate. The resistance to freeze/thaw cycles was not adequate. The amount of mortar adhered to the recycled aggregate had little affect on the strength and durability of recycled concrete. It was concluded that the quality of recycled concrete aggregate depends on the quality of original concrete. 11 refs., 12 tabs., 11 figs.

  8. 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.

  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. Concrete Pavement Joint Deterioration

    OpenAIRE

    2016-01-01

    Concrete pavements are an important part of our national infrastructure. In recent years the relatively small number of reported joints deteriorating prematurely in concrete pavements around Indiana has increased. Changes over the past 45 years in INDOT specification, pavement materials, designs and construction practices, and current de-icing materials were examined and related to the durability of concrete at the joints of existing pavements. A survey of concrete pavements across the state ...

  11. 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...

  12. 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.

  13. 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.

  14. 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...

  15. Assessment of low temperature cracking in asphalt pavement mixes and rheological performance of asphalt binders

    Science.gov (United States)

    Sowah-Kuma, David

    Government spends a lot of money on the reconstruction and rehabilitation of road pavements in any given year due to various distresses and eventual failure. Low temperature (thermal) cracking, one of the main types of pavement distress, contributes partly to this economic loss, and comes about as a result of accumulated tensile strains exceeding the threshold tensile strain capacity of the pavement. This pavement distress leads to a drastic reduction of the pavement's service life and performance. In this study, the severity of low temperature (thermal) cracking on road pavements selected across the Province of Ontario and its predicted time to failure was assessed using the AASTHO Mechanistic-Empirical Pavement Design Guide (MEPDG) and AASHTOWARE(TM) software, with inputs such as creep compliance and tensile strength from laboratory test. Highway 400, K1, K2, Y1, Sasobit, Rediset LQ, and Rediset WMX were predicted to have a pavement in-service life above 15 years. Additionally, the rheological performance of the recovered asphalt binders was assessed using Superpave(TM) tests such as the dynamic shear rheometer (DSR) and bending beam rheometer (BBR). Further tests using modified standard protocols such as the extended bending beam rheometer (eBBR) (LS-308) test method and double-edge notched tension (DENT) test (LS-299) were employed to evaluate the failure properties associated with in service performance. The various rheological tests showed K1 to be the least susceptible to low temperature cracking compared to the remaining samples whiles Highway 24 will be highly susceptible to low temperature cracking. X-ray fluorescence (XRF) analysis was performed on the recovered asphalt binders to determine the presence of metals such as zinc (Zn) and molybdenum (Mo) believed to originate from waste engine oil, which is often added to asphalt binders. Finally, the severity of oxidative aging (hardening) of the recovered asphalt binders was also evaluated using the

  16. 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.

  17. 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.

  18. 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.

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

    Directory of Open Access Journals (Sweden)

    Hui Yao

    2016-01-01

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

  20. [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.

  1. Performance of Asphalt Mixture Fatigue Research Adding the Ballast and RAP%添加底碴与 RAP 的沥青混合料疲劳性能研究

    Institute of Scientific and Technical Information of China (English)

    黄书科

    2015-01-01

    This study used in AC -10 as the softener,viscosity of control target is 2000 poise,in accordance with the ratio of regeneration design calculation asphalt content,and according to different content at the bottom of the design in accordance with the return to call high tar content.Then the inciner-ator bottom dross and recycled asphalt concrete are the basic physical properties test,using the SGC pro-portioning design fatigue specimens,as a supplement to different levels of incinerator bottom dross and re-cycling of asphalt concrete,both the evaluation to the effect of relaxation modulus and fatigue properties of asphalt concrete.Experimental results show that the recycled asphalt concrete to replace high volume re-laxation modulus maximum value will increase,add a maximum of specimens of RAP for not add 1.5 to 2 times,speculation for the aging of asphalt recycling material contains specimen stiffness to improve the effects of the.%使用 AC -10(粘度分级)为软化剂,对焚化炉底碴以及回收沥青混凝土进行基本物理性质试验,评估两者对于沥青混凝土松弛模量以及疲劳性质的影响。试验结果显示,添加 RAP 的试件的最大值为未添加的1.5至2倍。而天然粒料取代量高的情况下,试件松弛模量平缓值有下降的趋势,这可能受底碴本身多孔易碎性的结构特性影响。回收料含量高的试件,微观裂缝发生的荷载次数有下降趋势,底碴含量增加至30%时较易生成微观裂缝;而底碴含量增加至30%以及 RAP 含量增加至40%时,疲劳寿命有下降的趋势。各种评估疲劳寿命的方式差异不大,都可有效评估。

  2. Quantitative exposure matrix for asphalt fume, total particulate matter, and respirable crystalline silica among roofing and asphalt manufacturing workers.

    Science.gov (United States)

    Fayerweather, William E; Trumbore, David C; Johnson, Kathleen A; Niebo, Ronald W; Maxim, L Daniel

    2011-09-01

    This paper summarizes available data on worker exposures to asphalt fume (soluble fraction), total particulate matter, and respirable crystalline silica (quartz) [hereinafter RCS] over a 30-year period in Owens Corning's asphalt production and roofing manufacturing plants. For the period 1977 through 2006, the air-monitoring database contains more than 1,400 personal samples for asphalt fume (soluble fraction), 2,400 personal samples for total particulate, and 1,300 personal samples for RCS. Unique process-job categories were identified for the asphalt production and roofing shingle manufacturing plants. Quantitative exposures were tabulated by agent, process-job, and calendar period to form an exposure matrix for use in subsequent epidemiologic studies of the respiratory health of these workers. Analysis of time trends in exposure data shows substantial and statistically significant exposure reductions for asphalt fume (soluble fraction), total particulate matter, and respirable crystalline silica at Owens Corning plants. Cumulative distribution plots for the most recent sampling period (2001-2006) show that 95% of the asphalt fume (soluble fraction) measurements were less than 0.25 mg/m3; 95% of the total particulate measurements were less than 2.2 mg/m3; and 95% of the RCS measurements were less than 0.05 mg/m3. Several recommendations are offered to improve the design of future monitoring efforts.

  3. 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...

  4. 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.

  5. EVALUATION OF TIRE RUBBER DISPOSAL IN CONCRETE FOR PAVEMENTS

    Directory of Open Access Journals (Sweden)

    Rosa Cristina Cecche Lintz

    2009-01-01

    Full Text Available The production of waste by the tire industry has been a growing problem, indicating the need for its reuse. More than thirty million tires are discharged per year in Brazil, where regulation for the environment states that for each four new tires, five unusable ones must be adequately disposed by manufacturers and importers. Paving consumes an extremely large quantity of materials, which can be the source of rational application of waste and rejected materials. Research shows that tire rubber can be added to asphalt, which increases its durability and improves pavement quality and safety conditions by absorbing the rubber elastic properties, and also be used for architectural applications, among others. This study deals with the addition of rubber fibers from tire crushing in concrete for roadway pavements in order to provide proper indication about the alternative material disposal through an evaluation of the mechanical behavior of the modified concrete. Different concrete mixes were produced, within which, part of fine aggregates were substituted by tire rubber and mechanical experiment tests were performed, which show that, due to great resistance losses, the disposal of this alternative material in concrete should be considered for light traffic pavements, with the addition of rubber ranging up to 10% in mass.

  6. 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

  7. 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.

  8. Lunar concrete: Prospects and challenges

    Science.gov (United States)

    Khitab, Anwar; Anwar, Waqas; Mehmood, Imran; Kazmi, Syed Minhaj Saleem; Munir, Muhammad Junaid

    2016-02-01

    The possibility of using concrete as a construction material at the Moon surface is considered. Dissimilarities between the Earth and the Moon and their possible effects on concrete are also emphasized. Availability of constituent materials for concrete at lunar surface is addressed. An emphasis is given to two types of materials, namely, hydraulic concrete and sulfur concrete. Hydraulic concrete necessitates the use of water and sulfur concrete makes use of molten sulfur in lieu of cement and water.

  9. 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.

  10. Adhesion Evaluation of Asphalt-Aggregate Interface Using Surface Free Energy Method

    OpenAIRE

    Jie Ji; Hui Yao; Luhou Liu; Zhi Suo; Peng Zhai; Xu Yang; Zhanping You

    2017-01-01

    The influence of organic additives (Sasobit and RH) and water on the adhesion of the asphalt-aggregate interface was studied according to the surface free energy theory. Two asphalt binders (SK-70 and SK-90), and two aggregate types (limestone and basalt) were used in this study. The sessile drop method was employed to test surface free energy components of asphalt, organic additives and aggregates. The adhesion models of the asphalt-aggregate interface in dry and wet conditions were establis...

  11. 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.

  12. Structural and Thermal Analysis of Asphalt Solar Collector Using Finite Element Method

    OpenAIRE

    Jinshah Basheer Sheeba; Ajith Krishnan Rohini

    2014-01-01

    The collection of solar energy using asphalt pavements has got a wide importance in the present energy scenario. Asphalt pavements subjected to solar radiation can reach temperature up to 70°C because of their excellent heat absorbing property. Many working parameters, such as pipe diameter, pipe spacing, pipe depth, pipe arrangement, and flow rate, influence the performance of asphalt solar collector. Existing literature on thermal energy extraction from asphalt pavements is based on the sma...

  13. Asphalt fume exposure levels in North American asphalt production and roofing manufacturing operations.

    Science.gov (United States)

    Axten, Charles W; Fayerweather, William E; Trumbore, David C; Mueller, Dennis J; Sampson, Arthur F

    2012-01-01

    This study extends by 8 years (1998-2005) a previous survey of asphalt fume exposures within North American asphalt processing and roofing product manufacturing workers. It focuses on characterizing personal, full-shift samples and seeks to address several limitations of the previous survey. Five major roofing manufacturers with established occupational health programs submitted workplace asphalt fume sampling results to a central repository for review and analysis. A certified industrial hygienist-led quality assurance team oversaw the data collection, consolidation, and analysis efforts. The analysis dataset consisted of 1261 personal exposure samples analyzed for total particulate (TP) and benzene soluble fraction (BSF) using existing NIOSH methods. For BSF, the survey's arithmetic (0.25 mg/m(3), SD = 0.62) and geometric (0.12 mg/m(3), GSD = 2.88) means indicate that the industry has sustained the control levels achieved in the late 1980s, early 1990s. Similar results were found for TP. The survey-wide summary statistics are consistent with other post-1990 multi-company exposure studies. Although these findings indicate that currently available controls are capable of achieving substantial (95%) compliance with the current threshold limit value in asphalt processing and inorganic shingle and roll plants, they also show that the majority of plants are not achieving this level of exposure control, and that exposures are significantly higher in plants making other product lines, particularly organic felt products. The current retrospective survey of existing company exposure data, like its predecessor, has several important limitations. These include lack of data on smaller manufacturers and on several commercially important product lines; insufficient information on the prevalence and effectiveness of engineering controls; no standard criteria by which to define and assess exposures in non-routine operations; and a paucity of exposure data collected as part of a

  14. Performances and Durability of Asphalt Mixtures Made with Reclaimed Asphalt Pavement

    OpenAIRE

    Noferini, Luca

    2016-01-01

    According to most recent surveys, 265 mil tonnes of asphalt for road applications were produced in the European area in 2014. In the same year, the amount of available RAP was more than 50 mil tonnes. The use of RAP in new blended mixes reduces the need of neat bitumen, making RAP recycling economically attractive. In spite of its economic and environmental benefits, the use of RAP is often subjected to restrictive policies pursued by agencies due to uncertainty related to RAP mixes field per...

  15. Long-term degradation (or improvement?) of cementitious grout/concrete for waste disposal at Hanford

    Energy Technology Data Exchange (ETDEWEB)

    Piepho, M.G. [Daniel B. Stephens & Associates, Inc., Richland, WA (United States)

    1997-12-31

    If grout and/or concrete barriers and containments are considered for long-term (500 yrs to 100,000 ) waste disposal, then long-term degradation of grout/cement materials (and others) need to be studied. Long-term degradations of a cementitious grout monolith (15.4mW x 10.4mH x 37.6mL) and its containment concrete shell and asphalt shell (each 1-m thick) were analyzed. The main degradation process of the concrete shell was believed to be fractures due to construction joints, shrinkage, thermal stress, settlement, and seismic events. A scenario with fractures was modeled (flow and transport model) for long-term risk performance (out to a million yrs). Even though the concrete/grout is expected to fracture, the concrete/grout chemistry, which has high Ph value, is very beneficial in causing calcite deposits from calcium in the water precipitating in the fractures. These calcite deposits will tend to plug the fracture and keep water from entering. The effectiveness of such plugging needs to be studied more. It`s possible that the plugged fractures are more impermeable than the original concrete/grout. The long-term performance of concrete/grout barriers will be determined by its chemistry, not its mechanical properties.

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

    NARCIS (Netherlands)

    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 surfac

  17. 40 CFR 436.60 - Applicability; description of the asphaltic mineral subcategory.

    Science.gov (United States)

    2010-07-01

    ... asphaltic mineral subcategory. 436.60 Section 436.60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS MINERAL MINING AND PROCESSING POINT SOURCE CATEGORY Asphaltic Mineral Subcategory § 436.60 Applicability; description of the asphaltic mineral subcategory....

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

    NARCIS (Netherlands)

    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 la

  19. 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…

  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. 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 * * *...

  2. Use of recycled plastic in concrete: a review.

    Science.gov (United States)

    Siddique, Rafat; Khatib, Jamal; Kaur, Inderpreet

    2008-01-01

    Numerous waste materials are generated from manufacturing processes, service industries and municipal solid wastes. The increasing awareness about the environment has tremendously contributed to the concerns related with disposal of the generated wastes. Solid waste management is one of the major environmental concerns in the world. With the scarcity of space for landfilling and due to its ever increasing cost, waste utilization has become an attractive alternative to disposal. Research is being carried out on the utilization of waste products in concrete. Such waste products include discarded tires, plastic, glass, steel, burnt foundry sand, and coal combustion by-products (CCBs). Each of these waste products has provided a specific effect on the properties of fresh and hardened concrete. The use of waste products in concrete not only makes it economical, but also helps in reducing disposal problems. Reuse of bulky wastes is considered the best environmental alternative for solving the problem of disposal. One such waste is plastic, which could be used in various applications. However, efforts have also been made to explore its use in concrete/asphalt concrete. The development of new construction materials using recycled plastics is important to both the construction and the plastic recycling industries. This paper presents a detailed review about waste and recycled plastics, waste management options, and research published on the effect of recycled plastic on the fresh and hardened properties of concrete. The effect of recycled and waste plastic on bulk density, air content, workability, compressive strength, splitting tensile strength, modulus of elasticity, impact resistance, permeability, and abrasion resistance is discussed in this paper.

  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. Inhalation and dermal exposure among asphalt paving workers.

    Science.gov (United States)

    McClean, M D; Rinehart, R D; Ngo, L; Eisen, E A; Kelsey, K T; Herrick, R F

    2004-11-01

    The primary objective of this study was to identify determinants of inhalation and dermal exposure to polycyclic aromatic compounds (PACs) among asphalt paving workers. The study population included three groups of highway construction workers: 20 asphalt paving workers, as well as 12 millers and 6 roadside construction workers who did not work with hot-mix asphalt. During multiple consecutive work shifts, personal air samples were collected from each worker's breathing zone using a Teflon filter and cassette holder connected in series with an XAD-2 sorbent tube, while dermal patch samples were collected from the underside of each worker's wrist. All exposure samples were analyzed for PACs, pyrene and benzo[a]pyrene. Inhalation and dermal PAC exposures were highest among asphalt paving workers. Among paving workers, inhalation and dermal PAC exposures varied significantly by task, crew, recycled asphalt product (RAP) and work rate (inhalation only). Asphalt mix containing high RAP was associated with a 5-fold increase in inhalation PAC exposures and a 2-fold increase in dermal PAC exposure, compared with low RAP mix. The inhalation PAC exposures were consistent with the workers' proximity to the primary source of asphalt fume (paver operators > screedmen > rakers > roller operators), such that the adjusted mean exposures among paver operators (5.0 microg/m3, low RAP; 24 microg/m3, high RAP) were 12 times higher than among roller operators (0.4 microg/m3, low RAP; 2.0 microg/m3, high RAP). The dermal PAC exposures were consistent with the degree to which the workers have actual contact with asphalt-contaminated surfaces (rakers > screedmen > paver operators > roller operators), such that the adjusted mean exposures among rakers (175 ng/cm2, low RAP; 417 ng/cm2, high RAP) were approximately 6 times higher than among roller operators (27 ng/cm2, low RAP; 65 ng/cm2, high RAP). Paving task, RAP content and crew were also found to be significant determinants of

  5. Nanostructured silicate polymer concrete

    Directory of Open Access Journals (Sweden)

    Figovskiy Oleg L'vovich

    2014-03-01

    Full Text Available It has been known that acid-resistant concretes on the liquid glass basis have high porosity (up to 18~20 %, low strength and insufficient water resistance. Significant increasing of silicate matrix strength and density was carried out by incorporation of special liquid organic alkali-soluble silicate additives, which block superficial pores and reduce concrete shrinkage deformation. It was demonstrated that introduction of tetrafurfuryloxisilane additive sharply increases strength, durability and shock resistance of silicate polymer concrete in aggressive media. The experiments showed, that the strength and density of silicate polymer concrete increase in case of decreasing liquid glass content. The authors obtained optimal content of silicate polymer concrete, which possesses increased strength, durability, density and crack-resistance. Diffusive permeability of concrete and its chemical resistance has been investigated in various corroding media.

  6. The Utilization of Graphene Oxide in Traditional Construction Materials: Asphalt

    Directory of Open Access Journals (Sweden)

    Wenbo Zeng

    2017-01-01

    Full Text Available In the advanced research fields of solar cell and energy storing materials, graphene and graphene oxide (GO are two of the most promising materials due to their high specific surface area, and excellent electrical and physical properties. However, they was seldom studied in the traditional materials because of their high cost. Nowadays, graphene and GO are much cheaper than before with the development of production technologies, which provides the possibility of using these extraordinary materials in the traditional construction industry. In this paper, GO was selected as a nano-material to modify two different asphalts. Then a thin film oven test and a pressure aging vessel test were applied to simulate the aging of GO-modified asphalts. After thermal aging, basic physical properties (softening point and penetration were tested for the samples which were introduced at different mass ratios of GO (1% and 3% to asphalt. In addition, rheological properties were tested to investigate how GO could influence the asphalts by dynamic shearing rheometer tests. Finally, some interesting findings and potential utilization (warm mixing and flame retardants of GO in asphalt pavement construction were explained.

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

    Science.gov (United States)

    Rajbongshi, Pabitra; Thongram, Sonika

    2016-09-01

    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. 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.

  9. Laboratory Measurements of Particulate Matter Concentrations from Asphalt Pavement Abrasion

    Science.gov (United States)

    Fullová, Daša; Đurčanská, Daniela

    2016-12-01

    The issue of emissions from road traffic is compounded by the fact that the number of vehicles and driven kilometres increase each year. Road traffic is one of the main sources of particulate matter and traffic volume is still increasing and has unpleasant impact on longevity of the pavements and the environment. Vehicle motions cause mechanical wearing of the asphalt pavement surface - wearing course by vehicle tyres. The contribution deals with abrasion of bituminous wearing courses of pavements. The asphalt mixtures of wearing courses are compared in terms of mechanically separated particulate matter. The samples of asphalt mixtures were rutted in wheel tracking machine. The particulate matter measurements were performed in laboratory conditions. The experimental laboratory measurements make it possible to sample particulates without contamination from exhaust emissions, abraded particles from vehicles, resuspension of road dust and climate affects. The contribution offers partial results of measurements on six trial samples of asphalt mixtures with different composition. It presents particulate matter morphology and the comparison of rutted asphalt samples in terms of PM mass concentrations and chemical composition.

  10. 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.

  11. 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.

  12. Aqueous leaching of polycyclic aromatic hydrocarbons from bitumen and asphalt.

    Science.gov (United States)

    Brandt, H C; de Groot, P C

    2001-12-01

    The application of bitumen in, e.g. asphalt roads, roofs and hydraulic applications will lead to the leaching of compounds from the bitumen/asphalt into the environment. Because polycyclic aromatic hydrocarbons (PAHs) are present in bitumen, static and dynamic leach tests have been performed to study the leaching behaviour of this class of compounds. Nine petroleum bitumens covering a representative range of commercially available products and one asphalt made from one of the bitumens have been tested in a static leach test. The asphalt has been also subjected to a dynamic leach test. The main conclusions are that a 30h dynamic leach test is sufficient to determine the equilibrium concentration that will be reached after bitumen or asphalt has been in contact with the water for more than 3-6 days. As an alternative to performing a leach test, this concentration can be calculated from the PAH concentrations in the bitumen, and their distribution coefficients, as calculated here, or from their aqueous solubilities. The equilibrium PAH concentrations in the leach water from bitumens stay well below the surface water limits that exist in several EEC-countries and are also more than an order of magnitude lower than the current EEC limits for potable water.

  13. 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.

  14. Laboratory Measurements of Particulate Matter Concentrations from Asphalt Pavement Abrasion

    Directory of Open Access Journals (Sweden)

    Fullová Daša

    2016-12-01

    Full Text Available The issue of emissions from road traffic is compounded by the fact that the number of vehicles and driven kilometres increase each year. Road traffic is one of the main sources of particulate matter and traffic volume is still increasing and has unpleasant impact on longevity of the pavements and the environment. Vehicle motions cause mechanical wearing of the asphalt pavement surface - wearing course by vehicle tyres. The contribution deals with abrasion of bituminous wearing courses of pavements. The asphalt mixtures of wearing courses are compared in terms of mechanically separated particulate matter. The samples of asphalt mixtures were rutted in wheel tracking machine. The particulate matter measurements were performed in laboratory conditions. The experimental laboratory measurements make it possible to sample particulates without contamination from exhaust emissions, abraded particles from vehicles, resuspension of road dust and climate affects. The contribution offers partial results of measurements on six trial samples of asphalt mixtures with different composition. It presents particulate matter morphology and the comparison of rutted asphalt samples in terms of PM mass concentrations and chemical composition.

  15. Concrete portable handbook

    CERN Document Server

    Woodson, R Dodge

    2011-01-01

    Whether or not, you are on the job site or back in the office, this book will help you to avoid mistakes, code violations, and wasted time and money. The book's four part treatment begins with constituent materials followed by self contained parts on Concrete Properties, Processes, and Concrete Repair and Rehabilitation. Designed to be an ""all in one"" reference, the author includes a wealth information for the most popular types of testing. This includes: Analysis of Fresh Concrete; Testing Machines; Accelerated Testing Methods; Analysis of Hardened Concrete and Mortar; Core Sampl

  16. Asphalt fume dermal carcinogenicity potential: I. dermal carcinogenicity evaluation of asphalt (bitumen) fume condensates.

    Science.gov (United States)

    Clark, Charles R; Burnett, Donald M; Parker, Craig M; Arp, Earl W; Swanson, Mark S; Minsavage, Gary D; Kriech, Anthony J; Osborn, Linda V; Freeman, James J; Barter, Robert A; Newton, Paul E; Beazley, Shelley L; Stewart, Christopher W

    2011-10-01

    Asphalt (bitumen) fume condensates collected from the headspace above paving and Type III built up roofing asphalt (BURA) tanks were evaluated in two-year dermal carcinogenicity assays in male C3H/HeNCrl mice. A third sample was generated from the BURA using a NIOSH laboratory generation method. Similar to earlier NIOSH studies, the BURA fume condensates were applied dermally in mineral oil twice per week; the paving sample was applied 7 days/week for a total weekly dose of 50 mg/wk in both studies. A single benign papilloma was observed in a group of 80 mice exposed to paving fume condensate at the end of the two-year study and only mild skin irritation was observed. The lab generated BURA fume condensate resulted in statistically significant (P<0.0001) increases in squamous cell carcinomas (35 animals or 55% of animals at risk). The field-matched BURA condensate showed a weaker but significant (P=0.0063) increase (8 carcinomas or 13% of animals) and a longer average latency (90 weeks vs. 76 for the lab fume). Significant irritation was observed in both BURA condensates. It is concluded that the paving fume condensate was not carcinogenic under the test conditions and that the field-matched BURA fume condensate produced a weak tumor response compared to the lab generated sample.

  17. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Hartley, J.N.; Koehmstedt, P.L; Esterl, D.J.; Freeman, H.D.; Buelt, J.L.; Nelson, D.A.; Elmore, M.R.

    1981-05-01

    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.

  20. Deformation Parameters and Fatigue of the Recycled Asphalt Mixtures

    Science.gov (United States)

    Šrámek, Juraj

    2015-12-01

    The deformational properties of asphalt mixtures measured by dynamic methods and fatigue allow a design the road to suit the expected traffic load. Quality of mixtures is also expressed by the resistance to permanent deformation. Complex modulus of stiffness and fatigue can reliably characterize the proposed mixture of asphalt pavement. The complex modulus (E*) measurement of asphalt mixtures are carried out in laboratory of Department of Construction Management at University of Žilina by two-point bending test method on trapezoid-shaped samples. Today, the fatigue is verified on trapezoid-shaped samples and is assessed by proportional strain at 1 million cycles (ɛ6). The test equipment and software is used to evaluate fatigue and deformation characteristics.

  1. 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.

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

    Institute of Scientific and Technical Information of China (English)

    曾靖超

    2014-01-01

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

  3. LIGHTWEIGHT CONCRETE BASED GRANSHLAK

    Directory of Open Access Journals (Sweden)

    NETESA M. I.

    2016-02-01

    Full Text Available Raising of problem. Concrete advisable to obtain a low strength with local secondary resources for recycling and reduce the environmental burden on the environment. But it is important to design such concrete compositions with a reduced flow of cement. It is known that the coefficient of efficiency of use of cement in the concrete of the heavy and B10 is less than about 0.5, which is almost two times smaller than in class B15 concrete and above. Even lower coefficient of efficiency in light concrete cement low strength. Therefore, it is important to find patterns determining the composition of lightweight concrete based on local-products industry with more efficient use of cement in them. Purpose.. Based on the analysis of earlier research results, including with the use of methods of mathematical planning of experiments to determine the concrete contents, which can provide the requirements for the underlying layers of the floor, the compressive strength of which should correspond to the class B5. It is important to provide the required strength at minimum flow of the cement, which is the most expensive and energy-intensive part of concrete. Conclusion. Analysis of the test results of control samples of concrete in 28-day-old, the following laws. The required tensile strength of concrete compressive strength of 7.0 MPa can be obtained in the test range when used in formulations as a filler as the Dnieper hydroelectric power station fly ash and tailings Krivoy Rog iron ore YuGOK. To ensure providing the required characteristic strength of the concrete in the underlying layers of the floor is advisable to use a nominal composition per cubic meter of concrete: cement 160 kg granshlaka Plant named after Petrovsky, 675 kg of fly ash Dnieper HPP 390 kg, 400 kg of sand, 230 liters of water. Thus, while ensuring rational grain composition components can obtain the desired strength lightweight concrete based granshlaka plant Petrovsky, using as fillers

  4. Open Graded Asphalt Mixture Design for Environmentally Friendly Road

    Science.gov (United States)

    Setyawan, A.; Suryoto; Sumarsono, A.; Widyastuti, S.

    2017-02-01

    The road is an important infrastructure to support various economic development. By increasing the population, the constructions of road infrastructure are obviously required and cover more land use area, consequently narrowed the areas for water absorption into the land. Therefore, it is necessary to improve more environmentally friendly of road constructions, in this case is by using open graded asphalt. Open graded asphalt is the mixture of asphalt with low fine aggregate content to produce a high percentage of air voids, which expected to be able to absorb water into the land underneath. This observation uses laboratory experiment method. Materials that are used are natural gravel and the volcanic gravel, 60/70 asphalt penetration and stone dust filler. The tests performed for the samples are Marshall test, falling head water permeability, indirect tensile strength and unconfined compressive strength. The optimum bitumen content for each type of aggregate have been found to be 2.95% for natural gravel and 4.65% for volcanic gravel. Open graded asphalt porosity is 26.52% for natural gravel, whereas the volcanic gravel is 22.31%. The vertical and horizontal permeability for natural gravel are 1.25 cm/second and 0.92 cm/second, respectively. Whereas, for the volcanic gravel is 1.43 cm/second and 1.10 cm/second, respectively. Indirect tensile strength (ITS) value for natural gravel is 59.49 KPa whereas the volcanic gravel is 74.84 KPa. The unconfined compressive strength (UCS) value for natural gravel is 1070.63 KPa, whereas the volcanic gravel is 1120.69 KPa. It is concluded that the open graded porous asphalt is only compatible for low volume traffic road and need improvement to be able to be used as standard road.

  5. Rutting Prediction in Asphalt Pavement Based on Viscoelastic Theory

    Directory of Open Access Journals (Sweden)

    Nahi Mohammed Hadi

    2016-01-01

    Full Text Available Rutting is one of the most disturbing failures on the asphalt roads due to the interrupting it is caused to the drivers. Predicting of asphalt pavement rutting is essential tool leads to better asphalt mixture design. This work describes a method of predicting the behaviour of various asphalt pavement mixes and linking these to an accelerated performance testing. The objective of this study is to develop a finite element model based on viscoplastic theory for simulating the laboratory testing of asphalt mixes in Hamburg Wheel Rut Tester (HWRT for rutting. The creep parameters C1, C2 and C3 are developed from the triaxial repeated load creep test at 50°C and at a frequency of 1 Hz and the modulus of elasticity and Poisson’ s ratio determined at the same temperature. Viscoelastic model (creep model is adopted using a FE simulator (ANSYS in order to calculate the rutting for various mixes under a uniform loading pressure of 500 kPa. An eight-node with a three Degrees of Freedom (UX, UY, and UZ Element is used for the simulation. The creep model developed for HWRT tester was verified by comparing the predicted rut depths with the measured one and by comparing the rut depth with ABAQUS result from literature. Reasonable agreement can be obtained between the predicted rut depths and the measured one. Moreover, it is found that creep model parameter C1 and C3 have a strong relationship with rutting. It was clear that the parameter C1 strongly influences rutting than the parameter C3. Finally, it can be concluded that creep model based on finite element method can be used as an effective tool to analyse rutting of asphalt pavements.

  6. Adhesion Evaluation of Asphalt-Aggregate Interface Using Surface Free Energy Method

    Directory of Open Access Journals (Sweden)

    Jie Ji

    2017-02-01

    Full Text Available The influence of organic additives (Sasobit and RH and water on the adhesion of the asphalt-aggregate interface was studied according to the surface free energy theory. Two asphalt binders (SK-70 and SK-90, and two aggregate types (limestone and basalt were used in this study. The sessile drop method was employed to test surface free energy components of asphalt, organic additives and aggregates. The adhesion models of the asphalt-aggregate interface in dry and wet conditions were established, and the adhesion work was calculated subsequently. The energy ratios were built to evaluate the effect of organic additives and water on the adhesiveness of the asphalt-aggregate interface. The results indicate that the addition of organic additives can enhance the adhesion of the asphalt-aggregate interface in dry conditions, because organic additives reduced the surface free energy of asphalt. However, the organic additives have hydrophobic characteristics and are sensitive to water. As a result, the adhesiveness of the asphalt-aggregate interface of the asphalt containing organic additives in wet conditions sharply decreased due to water damage to asphalt and organic additives. Furthermore, the compatibility of asphalt, aggregate with organic additive was noted and discussed.

  7. [Biological monitoring of PAH exposure among asphalt workers].

    Science.gov (United States)

    Campo, Laura; Calisti, Roberto; Polledri, Elisa; Barretta, Francesco; Stopponi, Roberta; Massacesi, Stefania; Bertazzi, Pieralberto; Fustinoni, Silvia

    2011-01-01

    Aim of this work was the assessment of exposure to polycyclic aromatic hydrocarbons (PAHs) by urinary 1-hydroxypyrene (1-OHPyr) in asphalt workers. Median levels of 1-OHPyr resulted higher in asphalt workers than in controls (184 vs. < 20 ng/L, p < 0.001). The determinants of exposure of 1-OHPyr resulted smoking habit, the number of consecutive days at work and the job task; 1-OHPyr was also associated to urinary creatinine. End of work week 1-OHPyr is suggested as an useful indicator of occupational exposure to PAHs in bitumen fumes.

  8. Characterization and thermal behavior of polymer-modified asphalt

    Directory of Open Access Journals (Sweden)

    Maria da Conceição Cavalcante Lucena

    2004-12-01

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

  9. Road safety effects of porous asphalt: a systematic review of evaluation studies

    DEFF Research Database (Denmark)

    Elvik, R.; Greibe, Poul

    2005-01-01

    This paper presents a systematic review of studies that have evaluated the effects on road safety of porous asphalt. Porous asphalt is widely used on motorways in Europe, mainly in order to reduce traffic noise and increase road capacity. A meta-analysis was made of six studies, containing a total...... of eighteen estimates of the effect of porous asphalt on accident rates. No clear effect on road safety of porous asphalt was found. All summary estimates of effect indicated very small changes in accident rates and very few were statistically significant at conventional levels. Studies that have evaluated...... the effects of porous asphalt on nine different risk factors associated with accident occurrence were also reviewed. It was found that four of the risk factors were favourably influenced by porous asphalt, three were adversely influenced, and two were not influenced by porous asphalt. The net impact...

  10. [Anesthetic management in a patient with head and neck burn by asphalt].

    Science.gov (United States)

    Suzuki, Nao; Niiyama, Yukitoshi; Tokinaga, Yasuyuki; Yamakage, Michiaki

    2013-10-01

    In cases of facial burns caused by molten asphalt, examination for possible airway burns and early removal of the asphalt should be carried out to prevent chemical-induced tissue damage and infection. However, asphalt that has adhered to tissues is difficult to remove. A 35-year-old male with burns caused by molten asphalt was scheduled for emergency debridement. He had 6% body surface area burns on his face and neck. He was not able to open his eyes due to the adherence of asphalt. His respiratory condition was stable and a perioperative fiberoptic view revealed no airway burns. After awake intubation, orange peel oil was used to remove the asphalt from his face and eyes. Since orange peel oil does not contain any harmful substances, it is effective for removing asphalt without causing tissue damage.

  11. Concrete-Design

    Directory of Open Access Journals (Sweden)

    Leczovics Péter

    2014-12-01

    Full Text Available Present paper introduces a new interpretation of concrete, demonstrating some extreme possibilities of this rigid material such as a design element. In the first part a brief overview of the previous achievements are shown. The second part of this paper focuses on the relationship between concrete and fashion.

  12. Concrete, hardened: Self desiccation

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan De Place; Hansen, Kurt Kielsgaard; Persson, Bertil

    1999-01-01

    The test method covers the determination of internal relative humidity (RH) in hardened concrete and cement mortar using RH instruments. The determination of RH is done on crushed samples of concrete or cement motar. This test method is only for measuring equipment which gives off or takes up...

  13. concrete5 Beginner's Guide

    CERN Document Server

    Laubacher, Remo

    2011-01-01

    This book is part of Packt's Beginner's Guide series. You will be guided through the set up of a Concrete5 site with step-by-step practical examples. This book is ideal for developers who would like to build their first site with Concrete5. Some k

  14. Stormwater quality of spring-summer-fall effluent from three partial-infiltration permeable pavement systems and conventional asphalt pavement.

    Science.gov (United States)

    Drake, Jennifer; Bradford, Andrea; Van Seters, Tim

    2014-06-15

    This study examined the spring, summer and fall water quality performance of three partial-infiltration permeable pavement (PP) systems and a conventional asphalt pavement in Ontario. The study, conducted between 2010 and 2012, compared the water quality of effluent from two Interlocking Permeable Concrete Pavements (AquaPave(®) and Eco-Optiloc(®)) and a Hydromedia(®) Pervious Concrete pavement with runoff from an Asphalt control pavement. The usage of permeable pavements can mitigate the impact of urbanization on receiving surface water systems through quantity control and stormwater treatment. The PP systems provided excellent stormwater treatment for petroleum hydrocarbons, total suspended solids, metals (copper, iron, manganese and zinc) and nutrients (total-nitrogen and total-phosphorus) by reducing event mean concentrations (EMC) as well as total pollutant loadings. The PPs significantly reduced the concentration and loading of ammonia (NH4(+)+NH3), nitrite (NO2(-)) and organic-nitrogen (Org-N) but increased the concentration and loading of nitrate (NO3(-)). The PP systems had mixed performances for the treatment of phosphate (PO4(3-)). The PP systems increased the concentration of sodium (Na) and chloride (Cl) but EMCs remained well below recommended levels for drinking water quality. Relative to the observed runoff, winter road salt was released more slowly from the PP systems resulting in elevated spring and early-summer Cl and Na concentrations in effluent. PP materials were found to introduce dissolved solids into the infiltrating stormwater. The release of these pollutants was verified by additional laboratory scale testing of the individual pavement and aggregate materials at the University of Guelph. Pollutant concentrations were greatest during the first few months after construction and declined rapidly over the course of the study.

  15. The humoral immune response of mice exposed to simulated road paving-like asphalt fumes.

    Science.gov (United States)

    Anderson, Stacey E; Munson, Albert E; Tomblyn, Seth; Meade, B Jean; Diotte, Nicole M

    2008-07-01

    Asphalt is a complex mixture of organic molecules, including polycyclic aromatic hydrocarbons (PAH), which have been reported to cause serious adverse health effects in humans. Workers in manufacturing and construction trades exposed to asphalt are potentially at risk for being exposed to asphalt fumes and PAHs. Epidemiological investigations have collected mounting evidence that chemicals found in asphalt fumes present carcinogenic and possibly immunotoxic hazards. Studies evaluating the immunotoxic effects of asphalt fume are limited due to the large number of variables associated with asphalt fume exposures. This work investigates the immuno-toxic effects of road paving-like asphalt fume by analyzing the in vivo IgM response to a T-dependent antigen after exposure to whole, vapor, and particulate phase road paving-like asphalt fumes and asphalt fume condensate. Systemic exposures via intraperitoneal injection of asphalt fume condensate (at 0.625 mg/kg) and the particulate phase (at 5 mg/kg) resulted in significant reductions in the specific spleen IgM response to SRBC. Pharyngeal aspiration of the asphalt fume condensate (at 5 mg/kg) also resulted in significant suppression of the IgM response to SRBC. A significant reduction in the specific spleen IgM activity was observed after inhalation exposure to whole asphalt fumes (35 mg/m(3)) and the vapor components (11 mg/m(3)). Dermal exposures to the asphalt fume condensate resulted in significant reductions in the total (at 50 mg/kg) and specific (at 250 mg/kg) spleen IgM response to SRBC. These results demonstrate that exposure to road paving-like asphalt fumes is immunosuppressive through systemic, respiratory, and dermal routes of exposure in a murine model and raise concerns regarding the potential for adverse immunological effects.

  16. Effects of asphalt rejuvenator on thermal and mechanical properties on oxidized hot mixed asphalt pavements

    Science.gov (United States)

    Farace, Nicholas A.; Buttlar, William G.; Reis, Henrique

    2016-04-01

    The utilization of asphalt rejuvenator, and its effectiveness for restoring thermal and mechanical properties was investigated via Disk-shaped Compact Tension (DC(T)) and acoustic emission (AE) testing for determining mechanical properties and embrittlement temperatures of the mixtures. During the DC(T) testing the fracture energies and peak loads were used to measure the resistance of the rejuvenated asphalt to low temperature cracking. The AE testing monitored the acoustic emission activity while the specimens were cooled from room temperature to -40 °C to estimate the temperature at which thermal cracking began (i.e. the embrittlement temperature). First, a baseline response was obtained by obtaining the mechanical and thermal response of virgin HMA samples and HMA samples that had been exposed to oxidative aging for 36 hours at 135°C. The results showed the virgin samples had much higher peak loads and fracture energies than the 36 hours aged samples. Acoustic Emission showed similar results with the virgin samples having embrittlement temperatures 10 °C cooler than the 36 hours aged specimens. Then, overaged for 36 hours specimens were treated different amounts of rejuvenator (10%, 15%, and 20% by weight of binder content) and left to dwell for increased amount of time periods varying from one to eight weeks. It was observed that the AE results showed an improvement of embrittlement temperature with increasing with the dwell times. The 8 weeks specimens had cooler embrittlement temperatures than the virgin specimens. Finally, the low temperature effects on fracture energy and peak load of the rejuvenated asphalt was investigated. Rejuvenator was applied (10% by weight of binder) to specimens aged 36 hours at 135 °C, and the dwell time was varied from 1 to 4 weeks. The results showed that the peak loads were restored to levels of the virgin specimens, and the fracture energies improved to levels beyond that of the virgin specimens. The results also showed a

  17. Environmental Aspects of Use of Impregnating Compositions for Protection the Asphalt Concrete Road

    Directory of Open Access Journals (Sweden)

    Yulia A. Ubaskina

    2016-12-01

    Full Text Available The paper describes the effect of climatic factors on the wear of the roadway. Also presents the calculation of emissions of harmful exhaust components in the atmosphere. The application of the impregnating composition to increase the life of maintenance-free operation of the roadway while reducing impact of road construction and materials to the environment.

  18. Compliance Testing of the Eglin AFB Asphalt Concrete Batch Plant, Eglin AFB, Florida

    Science.gov (United States)

    1989-06-01

    dards and designated as a nonattainrnent on paper and pressure sensitive tapes re- sene. distillate fuel oils, residual fuel oils. area under Rule...20332-6188 USAF Regional Medical Center Wiesbaden/ SGB 1 APO New York 09220-5300 OL AD, AFOEHL 1 APO San Francisco 96274-5000 USAFSAM/TSK 1 Brooks AFB

  19. Concrete sample point: 304 Concretion Facility

    Energy Technology Data Exchange (ETDEWEB)

    Rollison, M.D.

    1995-03-10

    This report contains information concerning the analysis of concretes for volatile organic compounds. Included are the raw data for these analysis and the quality control data, the standards data, and all of the accompanying chains-of-custody records and requests for special analysis.

  20. Dynamic Response of Concrete and Concrete Structures.

    Science.gov (United States)

    1986-05-30

    Strain Rate Effects on Fracture (ed. S. Mindess and S. P. Shah), Symposium ’- S, Boston, Dec. 1985, Materials Research Society Symp. Proceedings, ". Vol...Reinforced Concrete Subjected to Impact Loading," in Cement-Based Composites: Strain-Rate Effects on Fracture (ed. S. Mindess and S.P. Shah) Materials

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

    Institute of Scientific and Technical Information of China (English)

    马峰; 郝景贤; 傅珍; 汪立龙; 汪林兵

    2015-01-01

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

  2. Performance of Waterless Concrete

    Science.gov (United States)

    Toutanji, Houssam; Evans, Steve; Grugel, Richard N.

    2010-01-01

    The development of permanent lunar bases is constrained by performance of construction materials and availability of in-situ resources. Concrete seems a suitable construction material for the lunar environment, but water, one of its major components, is an extremely scarce resource on the Moon. This study explores an alternative to hydraulic concrete by replacing the binding mix of concrete (cement and water) with sulfur. Sulfur is a volatile element on the lunar surface that can be extracted from lunar soils by heating. Sulfur concrete mixes were prepared to investigate the effect of extreme environmental conditions on the properties of sulfur concrete. A hypervelocity impact test was conducted, having as its target a 5-cm cubic sample of sulfur concrete. This item consisted of JSC-1 lunar regolith simulant (65%) and sulfur (35%). The sample was placed in the MSFC Impact Test Facility s Micro Light Gas Gun target chamber, and was struck by a 1-mm diameter (1.4e-03 g) aluminum projectile at 5.85 km/s. In addition, HZTERN code, provided by NASA was used to study the effectiveness of sulfur concrete when subjected to space radiation.

  3. Design tool for the thermal energy potential of asphalt pavements

    NARCIS (Netherlands)

    Loomans, M.G.L.C.; Oversloot, H.P.; Bondt, A. de; Jansen, R.; Rij, H. van

    2003-01-01

    This paper describes the development of a design tool for the calculation of the thermal energy potential of a so-called asphalt collector. Two types of numerical models have been developed and validated against experimental results from a full-scale test-site. The validation showed to be a tedious

  4. Sinopec Wins Bid for Special Asphalt for Racing Track

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    @@ On February 13 Sinopec and Shanghai International Circuit held a signing ceremony in Beijing for the contract to supply special asphalt for racing track use. Mr. Wang Jiming,Vice Board Chairman and President of Sinopec and Mr. Wang Tianpu, Senior Vice President of Sinopec, attended the ceremony.

  5. The adoption of innovative asphalt equipment in road construction

    NARCIS (Netherlands)

    Habets, Thijs; Voordijk, Hans; Sijde, van der Peter

    2011-01-01

    Purpose – The purpose of this paper is to provide insight into the adoption process of innovative asphalt equipment in road construction and how the level of knowledge as characterised by the level of education in the companies affects this process. The emphasis is on equipment used for transporting

  6. Performance related characterisation of the mechanical behaviour of asphalt mixtures

    NARCIS (Netherlands)

    Molenaar, J.M.M.

    2004-01-01

    The investigation was undertaken to support innovations in the field of asphalt pavement design and material selection, and to be able to evaluate or judge the risk of failure and cost-effectiveness of newly developed paving materials in order to justify their application. To be able to determine th

  7. Assessment of Water Quality of Runoff from Sealed Asphalt Surfaces

    Science.gov (United States)

    This report discusses the results of runoff tests from recently-sealed asphalt surfaces conducted at EPA's Urban Watershed Research Facility (UWRF) in Edison, New Jersey. Both bench-scale panels and full-scale test plots were evaluated. Full-scale tests were performed on an asp...

  8. Asphalt and Wood Shingling. Roofing Workbook and Tests.

    Science.gov (United States)

    Brown, Arthur

    This combination workbook and set of tests contains materials on asphalt and wood shingling that have been designed to be used by those studying to enter the roofing and waterproofing trade. It consists of seven instructional units and seven accompanying objective tests. Covered in the individual units are the following topics: shingling…

  9. Compressive Strength Development and Microstrueture of Cement.asphalt Mortar

    Institute of Scientific and Technical Information of China (English)

    WANG Qiang; YAN Peiyu; KONG Xiangming; YANG Jinbo

    2011-01-01

    The compressive strength developing process and the microstructure of cement-asphalt mortar (CA mortar) were investigated.The fluidity of CA mortar has a great influence on its strength.The optimum value of spread diameter of slump flow test is in the range of 300 to 400 mm.The compressive strength of CA mortar keeps a relatively high growth rate in 56 days and grows slowly afterwards.The residual water of hydration in CA mortar freezes under minus environmental temperature which can lead to a significant reduction of the strength of CA mortar.Increasing A/C retards asphalt emulsion splitting and thus prolongs the setting process of CA mortar.The hydration products of cement form the major structural framework of hardened CA mortar and asphalt is a weak phase in the framework but improves the viscoelastic behavior of CA mortar.Therefore,asphalt emulsion should be used as much as possible on the condition that essential performance criterions of CA mortar are satisfied.

  10. Mechanistic and Economical Characteristics of Asphalt Rubber Mixtures

    Directory of Open Access Journals (Sweden)

    Mena I. Souliman

    2016-01-01

    Full Text Available Load associated fatigue cracking is one of the major distress types occurring in flexible pavement systems. Flexural bending beam fatigue laboratory test has been used for several decades and is considered to be an integral part of the new superpave advanced characterization procedure. One of the most significant solutions to prolong the fatigue life for an asphaltic mixture is to utilize flexible materials as rubber. A laboratory testing program was performed on a conventional and Asphalt Rubber- (AR- gap-graded mixtures to investigate the impact of added rubber on the mechanical, mechanistic, and economical attributes of asphaltic mixtures. Strain controlled fatigue tests were conducted according to American Association of State Highway and Transportation Officials (AASHTO procedures. The results from the beam fatigue tests indicated that the AR-gap-graded mixtures would have much longer fatigue life compared with the reference (conventional mixtures. In addition, a mechanistic analysis using 3D-Move software coupled with a cost analysis study based on the fatigue performance on the two mixtures was performed. Overall, analysis showed that AR modified asphalt mixtures exhibited significantly lower cost of pavement per 1000 cycles of fatigue life per mile compared to conventional HMA mixture.

  11. concrete5 cookbook

    CERN Document Server

    Strack, David

    2013-01-01

    The Cookbook-style recipes allow you to go both directly to your topic of interest or follow topics throughout a chapter to gain in-depth knowledge. This practical Cookbook will cater to the needs of both intermediate and advanced concrete5 developers.This book is geared towards intermediate to advanced PHP developers who would like to learn more about the concrete5 content management system. Developers already familiar with concrete5 will learn new time-saving tricks and will find the book to be a great reference tool.

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

    Directory of Open Access Journals (Sweden)

    Shakir.A.Al-Mishhadani

    2014-02-01

    Full Text Available 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 advantages. This studyfocusedto test and evaluates the emulsified asphalt material properties to be used as paving mixture.The tested properties of emulsified asphalt mixture were bulk density, air voids, dry Marshallstability, wet Marshall stability, retained Marshall stability, flow tests and compared with thecommon used specification.The results indicate that the emulsified asphalt type cationic slowsetting low viscosity (CSS-1 is very suitable with quartz type of aggregate from Al-Nibaayquarry. From many trial mixes it is found that the best percentages of initial residual bitumencontent to produced adequateresults for coating test ,mixing ,compaction ,curing and Marshallstability were ranged from (2.5%, 3%,3.5%,4% and 4.5%, andthe optimum percentage is(3.5%.Finally it can be conducted that the emulsified asphalt mixture is a suitable alternativemixture to the hot asphalt mixture for road construction and maintenance in Iraq.

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

    Directory of Open Access Journals (Sweden)

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

    2014-04-01

    Full Text Available 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 advantages. This studyfocusedto test and evaluates the emulsified asphalt material properties to be used as paving mixture.The tested properties of emulsified asphalt mixture were bulk density, air voids, dry Marshallstability, wet Marshall stability, retained Marshall stability, flow tests and compared with thecommon used specification.The results indicate that the emulsified asphalt type cationic slowsetting low viscosity (CSS-1 is very suitable with quartz type of aggregate from Al-Nibaayquarry. From many trial mixes it is found that the best percentages of initial residual bitumencontent to produced adequateresults for coating test ,mixing ,compaction ,curing and Marshallstability were ranged from (2.5%, 3%,3.5%,4% and 4.5%, andthe optimum percentage is(3.5%.Finally it can be conducted that the emulsified asphalt mixture is a suitable alternativemixture to the hot asphalt mixture for road construction and maintenance in Iraq.  

  14. Electrokenitic Corrosion Treatment of Concrete

    Science.gov (United States)

    Cardenas, Henry E (Inventor)

    2015-01-01

    A method and apparatus for strengthening cementitious concrete by placing a nanoparticle carrier liquid in contact with a first surface of a concrete section and inducing a current across the concrete section at sufficient magnitude and for sufficient time that nanoparticles in the nanoparticle carrier liquid migrate through a significant depth of the concrete section.

  15. Evaluation system for CO2 emission of hot asphalt mixture

    Directory of Open Access Journals (Sweden)

    Bo Peng

    2015-04-01

    Full Text Available The highway construction industry plays an important role in economic and development, but is also a primary source of carbon emission. Accordingly, with the global climate change, energy conservation and reduction of carbon emissions have become critical issues in the highway construction industry. However, to date, a model for the highway construction industry has not been established. Hence, to implement a low-carbon construction model for highways, this study divided asphalt pavement construction into aggregate stacking, aggregate supply, and other stages, and compiled a list of energy consumption investigation. An appropriate calculation model of CO2 emission was then built. Based on the carbon emission calculation model, the proportion of carbon emissions in each stage was analyzed. The analytic hierarchy process was used to establish the system of asphalt pavement construction with a judgment matrix, thereby enabling calculation of the weight coefficient of each link. In addition, the stages of aggregate heating, asphalt heating, and asphalt mixture mixing were defined as key stages of asphalt pavement construction. Carbon emissions at these stages accounted for approximately 90% of the total carbon emissions. Carbon emissions at each stage and their impact on the environment were quantified and compared. The energy saving construction schemes as well as the environmental and socioeconomic benefits were then proposed. Through these schemes, significant reductions in carbon emissions and costs can be achieved. The results indicate that carbon emissions reduce by 32.30% and 35.93%, whereas costs reduce by 18.58% and 6.03%. The proposed energy-saving and emission reduction scheme can provide a theoretical basis and technical support for the development of low-carbon highway construction.

  16. Corrosion-resistant sulfur concretes

    Science.gov (United States)

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

    1983-04-01

    Sulfur concretes have been developed by the Bureau of Mines as construction materials with physical and mechanical properties that suit them for use in acid and salt corrosive environments where conventional concretes fail. Mixture design methods were established for preparing sulfur concretes using different types of aggregates and recently developed mixed-modified sulfur cements. Bench-scale testing of the sulfur concretes has shown their potential value. Corrosion resistance, strength, and durability of sulfur concrete are superior to those of conventional materials. Field in situ evaluation tests of the sulfur concretes as replacement for conventional concrete materials are in progress in corrosive areas of 24 commercial chemical, fertilizer, and metallurgical plants.

  17. Concrete Research Facility

    Data.gov (United States)

    Federal Laboratory Consortium — This is a 20,000-sq ft laboratory that supports research on all aspects of concrete and materials technology. The staff of this facility offer wide-ranging expertise...

  18. Fracture Mechanics of Concrete

    DEFF Research Database (Denmark)

    Ulfkjær, Jens Peder

    Chapter 1 Chapter l contains the introduction to this thesis. The scope of the thesis is partly to investigate different numerical and analytical models based on fracture mechanical ideas, which are able to predict size effects, and partly to perform an experimental investigation on high-strength......Chapter 1 Chapter l contains the introduction to this thesis. The scope of the thesis is partly to investigate different numerical and analytical models based on fracture mechanical ideas, which are able to predict size effects, and partly to perform an experimental investigation on high......-strength concrete. Chapter 2 A description of the factors which influence the strength and cracking of concrete and high strength concrete is made. Then basic linear fracture mechanics is outlined followed by a description and evaluation of the models used to describe concrete fracture in tension. The chapter ends...

  19. Self-Healing Concrete

    Institute of Scientific and Technical Information of China (English)

    履之

    1994-01-01

    Although concrete is an excellent building material because of its abili-ty to withstand stress and compression, it is susceptible to cracking. Car-olyn Dry, an associate professor of architecture at the University of Illinois

  20. Prestressed concrete design

    CERN Document Server

    Hurst, MK

    1998-01-01

    This edition provides up-to-date guidance on the detailed design of prestressed concrete structures. All major topics are dealt with, including prestressed flat slabs, an important and growing application in the design of buildings.

  1. Towards small scale use of asphalt as a fuel. An application of interest to developing countries

    Energy Technology Data Exchange (ETDEWEB)

    Faber, J.

    2002-01-01

    This survey deals with the feasibility of the combustion of asphalt instead of firewood. On the seashores of the numerous islands of Indonesia, especially on those of south and southeast Sulawesi, mangrove forests are endangered by extensive logging, lately on an increasing scale by locals for whom firewood is the sole resource of energy. Urged by Yayasan-Sarna, an Indonesian non-governmental organisation of South East Sulawesi, the Dutch foundation Zephyr-Sama has prompted research on the feasibility to use asphalt from deposits on the island of Buton as a domestic fuel. This research was thought to possibly lead to the development of a porous plug stove, or to a stove in which carbonised bamboo containers filled with asphalt are used as fuel elements. This survey consists of a literature review and an overview of possible routes for controlled combustion of asphalt. Attention has been paid to the environmental effects of the combustion as well. The literature mainly shows side effects of combustion of asphalt, which provide some knowledge on the combustion process. No direct studies on the combustion of asphalt were found. To explore the bottlenecks of the combustion process, an asphalt candle was made, because the taper seemed an ideal capillary active carrier for fluid asphalt. However, this experimental candle did not bum, likely due to high viscosity at the base of the taper and clogging of carbonaceous residue at the liquid/gas interface of the taper. An increase of the porosity of asphalt gives a better chance for a propagating combustion. The pores may increase the diffusion rate of volatile components, thus increasing the combustion rate. However, if asphalt is heated it will melt and the fluid will block the pores. Its melting at a relatively low temperature is a big handicap of asphalt. To overcome this handicap, asphalt could be transported by capillary forces into the combustion zone and combust at solid/liquid/gas interfaces - like is happening in a

  2. Performance of "Waterless Concrete"

    Science.gov (United States)

    Toutanji, H. A.; Grugel, R. N.

    2009-01-01

    Waterless concrete consists of molten elementary sulfur and aggregate. The aggregates in a lunar environment will be lunar rocks and soil. Sulfur is present on the Moon in Troilite soil (FeS) and, by oxidation of the soil, iron and sulfur can be produced. Sulfur concrete specimens were cycled between liquid nitrogen (approx.]91 C) and room temperature (^21 C) to simulate exposure to a lunar environment. Cycled and control specimens were subsequently tested in compression at room temperatures (^21 C) and ^-101 C. Test results showed that due to temperature cycling, the compressive strength of cycled specimens was 20% of those non-cycled. This reduction in strength can be attributed to the large differences in thermal coefficients of expansion of the materials constituting the concrete which promoted cracking. Similar sulfur concrete mixtures were strengthened with short and long glass fibres. The lunar regolith simulant was melted in a 25 cc Pt- Rh crucible in a Sybron Thermoline high temperature MoSi2 furnace at melting temperatures of 1450 to 1600 C for times of 30 min to i hour. Glass fibres and small rods were pulled from the melt. The glass fibres were used to reinforce sulfur concrete plated to improve the flexural strength of the sulfur concrete. Beams strengthened with glass fibres showed to exhibit an increase in the flexural strength by as much as 45%.

  3. Recycled Concrete as Aggregate for Structural Concrete Production

    Directory of Open Access Journals (Sweden)

    Mirjana Malešev

    2010-04-01

    Full Text Available 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 recycled coarse aggregate (50% and 100% replacement of coarse recycled aggregate. Ninety-nine specimens were made for the testing of the basic properties of hardened concrete. Load testing of reinforced concrete beams made of the investigated concrete types is also presented in the paper. Regardless of the replacement ratio, recycled aggregate concrete (RAC had a satisfactory performance, which did not differ significantly from the performance of control concrete in this experimental research. However, for this to be fulfilled, it is necessary to use quality recycled concrete coarse aggregate and to follow the specific rules for design and production of this new concrete type.

  4. Lymphocyte DNA damage in Turkish asphalt workers detected by the comet assay.

    Science.gov (United States)

    Bacaksiz, Aysegul; Kayaalti, Zeliha; Soylemez, Esma; Tutkun, Engin; Soylemezoglu, Tulin

    2014-01-01

    Asphalt has a highly complex structure and it contains several organic compounds including polycyclic aromatic hydrocarbons and heterocyclic compounds. In this study, comet assay was used to detect the DNA damage in blood lymphocytes of 30 workers exposed to asphalt fumes and 30 nonexposed controls. This is the first report on Turkish asphalt workers' investigated DNA damage using the alkaline single cell gel electrophoresis (SCGE). The DNA damage was evaluated by the percentage of DNA in the comet tail (% tail DNA) for each cell. According to our results, workers exposed to asphalt fumes had higher DNA damage than the control group (p asphalt fumes caused a significant increase in DNA damage and the comet assay is a suitable method for determining DNA damage in asphalt workers.

  5. Influence of limestone fillers on combustion characteristics of asphalt mortar for pavements

    DEFF Research Database (Denmark)

    Ke, Wu; Kai, Zhu; Wu, Hao;

    2014-01-01

    Asphalt materials will be ignited and release significant toxic fumes within tunnel fires. Thus, combustion characteristics of asphalt materials used in road tunnel should be studied in order to limit such an adverse effect. In the present work we study the influence of limestone fillers...... on combustion characteristics of asphalt mortar by thermogravimetric and kinetic analysis. It is shown that the combustion of asphalt mortar is not just a linear superposition of asphalt and limestone. The limestone will increase the ignition point and the activation energy of the primary volatile release......, and will catalyze the char formation from the primary volatile release. Kinetic analysis shows that the primary volatile release stage of asphalt mortar combustion can be explained by a three-dimensional diffusion model, the secondary volatile release and char combustion stage can be explained by a model under...

  6. SGC tests for influence of material composition on compaction characteristic of asphalt mixtures.

    Science.gov (United States)

    Chen, Qun; Li, Yuzhi

    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 an optimal amount of fine aggregates for optimal compaction and that an appropriate amount of mineral powder will improve workability of mixtures, but overmuch mineral powder will make mixtures dry and hard. Conclusions based on SGC tests can provide basis for how to adjust material composition for improving compaction performance of asphalt mixtures, and for the designed asphalt mixture, its compaction performance can be predicted through these conclusions, which also contributes to the choice of compaction schemes.

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

    Directory of Open Access Journals (Sweden)

    Yingwei Ren

    2014-01-01

    Full Text Available 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 thicknesses were developed, and then the road performance evaluation method was presented. In addition, the initial investments, the costs of road maintenance, and middle-scale repair in a period were analyzed. For the light traffic and medium traffic example, using the value engineering method, the pavement performance and costs of which thickness varies from 6 cm to 10 cm were calculated and compared. It was concluded that value engineering was an effective method in deciding the asphalt pavement structure.

  8. The reinforcement and healing of asphalt mastic mixtures by rejuvenator encapsulation in alginate compartmented fibres

    Science.gov (United States)

    Tabaković, A.; Post, W.; Cantero, D.; Copuroglu, O.; Garcia, S. J.; Schlangen, E.

    2016-08-01

    This paper explores the potential use of compartmented alginate fibres as a new method of incorporating rejuvenators into asphalt pavement mixtures. The compartmented fibres are employed to locally distribute the rejuvenator and to overcome the problems associated with spherical capsules and hollow fibres. The work presents proof of concept of the encapsulation process which involved embedding the fibres into the asphalt mastic mixture and the survival rate of fibres in the asphalt mixture. To prove the effectiveness of the alginate as a rejuvenator encapsulating material and to demonstrate its ability survive asphalt production process, the fibres containing the rejuvenator were prepared and subjected to thermogravimetric analysis and uniaxial tensile test. The test results demonstrated that fibres have suitable thermal and mechanical strength to survive the asphalt mixing and compaction process. The CT scan of an asphalt mortar mix containing fibres demonstrated that fibres are present in the mix in their full length, undamaged, providing confirmation that the fibres survived the asphalt production process. In order to investigate the fibres physiological properties and ability to release the rejuvenator into cracks in the asphalt mastic, the environmental scanning electron microscope and optical microscope analysis were employed. To prove its success as an asphalt healing system, compartmented alginate fibres containing rejuvenator were embedded in asphalt mastic mix. The three point bend tests were performed on the asphalt mastic test samples and the degree to which the samples began to self-heal in response was measured and quantified. The research findings indicate that alginate fibres present a promising new approach for the development of self-healing asphalt pavement systems.

  9. Development of an innovative bio-binder using Asphalt-rubber technology

    OpenAIRE

    2013-01-01

    This research work evaluates several parameters that can affect Asphalt Rubber (AR) binder performance and applies the AR technology to the development of an innovative renewable bio-binder that can fully and cost-effectively replace asphaltic bitumen derived from petroleum in flexible pavement construction. The “Binder Accelerated Separator” method was used to divide the constituents of the Asphalt Rubber and bio-binder (residual binder and swelled rubber). The physical and chemi...

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

    OpenAIRE

    2014-01-01

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

  11. Laboratory and Field Evaluation of In-Place Asphalt Recycling Technologies for Small Airfield Repair

    Science.gov (United States)

    2013-06-01

    Recommendation of materials, equipment and process for in-place asphalt recycling Part I Laboratory Evaluation RAP Material Characterization • Binder...laboratory testing based upon their chemical properties and costs. Reclaimed asphalt pavement ( RAP ) material was obtained from both test sites for...Part I of this study was to conduct laboratory testing to:  characterize the reclaimed asphalt pavement ( RAP ) from the test sites,  evaluate how

  12. Engineering and Design: Use of Petroleum Contaminated Soil in Cold-Mix Asphalt Stabilized Base Course

    Science.gov (United States)

    2007-11-02

    and construction of mixtures using petroleum contaminated soil and similar hydrocarbon waste for cold -mix asphalt stabilized base course (ASB). This...also performed an analysis using the diesel contaminated soil as part of a cold mix asphalt mixture . The mixtures produced with and without contaminated...quality materials ( RAP and asphalt cement) and good mixture design, construction procedures, and quality control, a high quality base or intermediate

  13. Mechanism of Fume Suppression and Performance on Asphalt of Expanded Graphite for Pavement under High Temperature Condition

    Institute of Scientific and Technical Information of China (English)

    HUANG Gang; HE Zhaoyi; HUANG Yangcheng; ZHOU Chao; YUAN Xiaoya

    2014-01-01

    Fume suppression mechanisms and the effect of expanded graphite on the performance of asphalt were studied by applying infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and comprehensive thermal analysis (TG, DSC). The experimental results confirm that asphalt which is mixed with expandable graphite will expand in the process of hot mix, and the expanded graphite layer will swell by the light component in the asphalt. The light component in the asphalt and PAHs adsorption on expanded graphite surface or part of the plug in the expanded graphite layer between plates made nucleation crystallization growth. And the Van der Waals force and the bonding of the lattice can effectively restrain the asphalt fume release. Meanwhile, the expanding agent with oxidative can spread into the asphalt, leading to asphalt oxygenated and plastic abate, while the ductility decreases. Expanded graphite, SBS modifier and environment- friendly plasticizers are used to composite modified asphalt. According to asphalt fume release experiment, normal test of asphalt performance, Brookfield viscosity test, RTFOT test and asphalt mixture tests (high temperature stability, low temperature stability, water stability), it has been proven that the modified asphalt’s performance is better than that of matrix asphalt and equivalent to that of SBS modified asphalt. Furthermore, it has good fume suppression effect.

  14. Effects of Fibre Additive on the High Temperature Property of Asphalt Binder

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Polyester fibre and floc xylogen fibre were used to prepare fibre-asphalt binder.An SHRP's dynamic shear rheometer (DSR) was employed to investigate the rheology charac teristics of fibre-asphalt binder, andthe flow resistance of binder was revealed by combining the rutting parameter, G * / sinδ.The results indicate that both kinds of fibres remarkably improved the high temperature pe~orrnance of asphalt binder.At the same time, the reinforcement mechanism of the fibres in the asphalt binder was also analyzed.

  15. Assessing Mechanical Properties of Hot Mix Asphalt with Wire Wool Fibers

    OpenAIRE

    Ahmed N. Bdour; Yahia Khalayleh; Aslam A. Al-Omari

    2015-01-01

    This paper investigates the potential application of wire wool in the modification of hot asphalt mixes (HMA). Wire wool material is widely available at local markets as a by-product of wire wool industry and as waste products from homes. For the purpose of this study, wire wool was cut into small pieces so that it can be placed in the asphalt mixes. Different percentages of wire wool were incorporated with the hot asphalt mixes (0.0%, 0.25%, and 0.5%) of the total weight of the asphalt binde...

  16. Influence of crumb rubber and digestion time on the asphalt rubber binders

    OpenAIRE

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

    2006-01-01

    This paper shows the results of a study about the mechanical behavior of dense graded asphalt-rubber hot mixes prepared with two different types of asphalt-rubber binders. These asphalt-rubber binders were obtained with penetration grade asphalt (AC 50/70) mixed with 21% and 25% of crumb rubber in weight. The rubber was recycled from unserviceable tires using the ambient grinding process. Hot mixes made with the conventional binder AC 50/70 were also studied for comparison. The...

  17. The Silurian Reservoir Bed-Differentiated Asphalts in Tarim Basin and Modeling Experiments on Their Origin

    Institute of Scientific and Technical Information of China (English)

    刘洛夫; 刘宏江; 王洪玉; 曾溅辉

    2002-01-01

    There is a type of asphalt that originated from differentiation from reservoir bed (named reservoir bed-differentiated asphalt) in the Silurian asphaltic sandstones of the Tarim Basin. These asphalts are the result of second-time charging of hydrocarbons into the Silurian reservoir, which were derived from Lower Paleozoic source rocks. Asphalt was differentiated from the reservoir bed in the hydrocarbon gathering area of secondary migration. The differen tiation is caused by changes in reservoir physical properties when pearl or chain hydrocarbons migrating through and gathering in the reservoir bed, and light components are lost and heavy ones are involved in the formation of asphalt or heavy oil. There are two kinds of occurrence of these asphalts in the Silurian system of the Tarim Basin. One is the poor heavy oil layer with lower oil saturation in trap and the other is scattered hydrocarbon distributed along the transport layer and unconformity surface. Reservoir bed-differentiated asphalts have two characteristics: total hydrocarbon content is high in extractable organic matter and the ratio of saturated to aromatic hydrocarbon is usually greater than unity. The physically modeling experiment has confirmed these characteristics and the genesis of the reservoir bed-differentiated asphalts.

  18. Optimization of technical measures for improving high-temperature performance of asphalt-rubber mixture

    Institute of Scientific and Technical Information of China (English)

    Chuan Xiao; Tianqing Ling; Yanjun Qiu

    2013-01-01

    Asphalt-rubber pavements often become dam-aged in high-temperature regions and appear rutted or wavy, and experience slippage. To improve the high-tem-perature performance of the asphalt-rubber mixture, tech-nical measurements, such as, the optimal adjustment of gradation, technique of composite modification, and con-trol of compaction were investigated. An optimal adjust-ment of aggregate gradation based on stone matrix asphalt improves the high-temperature stability of the asphalt-rubber mixture significantly. Through composite modifi-cation, the effect of asphalt-rubber modification was enhanced, and the dynamic stability and relative defor-mation indices of the asphalt-rubber mixture were improved significantly. Furthermore, compaction parame-ters had a significant influence on the high-temperature stability of the asphalt-rubber mixture. The rolling times for compacting the asphalt-rubber mixture should be controlled to within 18-20 round-trips at a molding tem-perature at 180 ?C;if the rolling time is a 12 round-trip, the compaction temperature of the asphalt-rubber mixture should be controlled between 180 and 190 ?C.

  19. Full-Scale Accelerated Pavement Testing of Warm-Mix Asphalt (WMA) for Airfield Pavements

    Science.gov (United States)

    2014-01-01

    ER D C/ G SL T R -1 4 -3 Full-Scale Accelerated Pavement Testing of Warm-Mix Asphalt (WMA) for Airfield Pavements G eo te ch n ic al...2014 Full-Scale Accelerated Pavement Testing of Warm-Mix Asphalt (WMA) for Airfield Pavements Mariely Mejías-Santiago, Jesse D. Doyle, and John F... asphalt (WMA) mixtures designed for airfield pavements. Three WMA mixtures were evaluated and compared to a control hot-mix asphalt (HMA) mixture. Data

  20. The Silurian Reservoir Bed—Differentiated Asphalts in Tarim Basin and Modeling Experiments on Their Origin

    Institute of Scientific and Technical Information of China (English)

    刘洛夫; 刘宏江; 等

    2002-01-01

    There is a type of asphalt that originated from differentiation from reservoir bed (named reservoir bed-differentiated asphalt)in the Silurian asphaltic sandstones of the Tarim Basin.These asphalts are the result of second-time charging of hydrocarbons into the Silurian reservoir,which were derived from Lower Paleozoic source rocks.Asphalt was differentiated from the reservoir bed in the hydrocarbon gathering area of secondary migration.The different-tiation is caused by changes in reservoir physical properties when pearl or chain hydrocarbons migrating through and gathering in the reservoir bed,and light components are lost and heavy ones are involved in the formation of asphalt or heavy oil.There are two kinds of occurrence of these asphalts in the Silurian system of the Tarim Basin.One is the poor heavy oil layer with lower oil saturation in trap and the other is scattered hydrocarbon distributed along the trans-port layer and unconformity surface.Reservoir bed-differentiated asphalts have two characteris-tics:total hydrocarbon content is high in extractable organic matter and the ratio of saturated to aromatic hydrocarbon is usually greater than unity.The physically modeling experiment has confirmed these characteristics and the genesis of the reservoir bed-differentiated asphalts.

  1. An atomistic-based chemophysical environment for evaluating asphalt oxidation and antioxidants.

    Science.gov (United States)

    Pan, Tongyan; Sun, Lu; Yu, Qifeng

    2012-12-01

    Asphalt binders in service conditions are subject to oxidative aging that involves the reactions between oxygen molecules and the component species of bulk asphalt. As a result, significant alterations can occur to the desired physical and/or mechanical properties of asphalt. A common practice to alleviate asphalt aging has been to employ different chemical additives or modifiers as antioxidants. The current state of knowledge in asphalt oxidation and antioxidant evaluation is centered on determining the degradation of asphalt physical properties, mainly the viscosity and ductility. Such practices, although meeting direct engineering needs, do not contribute to the fundamental understanding of the aging and anti-oxidation mechanisms, and thereby developing anti-aging strategies. From this standpoint, this study was initiated to study the chemical and physical bases of asphalt oxidation, as well as the anti-oxidation mechanisms of bio-based antioxidants using the coniferyl-alcohol lignin as an example. A quantum chemistry (QC) based chemophysical environment is developed, in which the various chemical reactions between asphalt component species and oxygen, as well as the incurred physical changes are studied. X-ray photoelectron spectroscopy (XPS) was used to validate the modified and unmodified asphalt models.

  2. Application of minerals residues in the asphalt composition; Aplicacao de residuos minerais na composicao do asfalto

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Roberto Carlos da C.; Seidl, Peter Rudolf [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Escola de Quimica; Correia, Julio Cesar Guedes [Centro de Tecnologia Mineral - CETEM, Rio de Janeiro, RJ (Brazil)

    2004-07-01

    The performance of asphalt pavements depends mainly on the properties of their constituents: mineral aggregates and asphalt cement. The mineral aggregate represents about 95% in weight of asphalt mixtures having a significant influence on the properties and performance of these mixtures. Asphalt cement (CAP) corresponds to the smaller fraction but it is mainly responsible for adsorption on the mineral aggregates. The objective of this study was to evaluate the interaction between different CAPs with residues from granite saw wills in place of mineral aggregates that run up costs with extraction and processing in asphalt production. This way asphalt production costs as well as the environmental problems that are caused by mineral residue are reduced. Five different asphalt cements, referred to as A, B, C, D and E, and a granite residue were used in this work. The results indicated that the residue strongly absorbs all the CAPs that were studied; particularly CAP A, which is considered the most adequate for the production of asphalt from this residue. Preliminary tests this indicate that asphalt production can use mineral residues instead of mineral aggregates in its composition. (author)

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

    Science.gov (United States)

    Zhang, Feng; Yu, Jianying; Wu, Shaopeng

    2010-10-15

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2013-01-01

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

  5. The Effect of Thermal Stress on Asphalt Workers’ Function and Their Physiological Parameters

    OpenAIRE

    RAMAZAN MIRZAEI; ROOHALAH HAJIZADEH; KEYKAOUS AZRAH; MOHAMMADHOSEIN BEHESHTI

    2015-01-01

    Heat stress effects on physical and mental health of workers and decreases human function. Asphalt workers are both exposed to the heat of their working process and to the sun heat. This study aimed at evaluating thermal stress and its following function fall and the effect of asphalt work on the degree of heat stress and asphalt workers’ physiological parameters. The present study was done at the work location of 29 asphalt workers in Qum City,  central  Iran.  The  degree  of  thermal stres...

  6. ENHANCING ASPHALT RHEOLOGICAL BEHAVIOR AND AGING SUSCEPTIBILITY USING BIO-CHAR AND NANO-CLAY

    OpenAIRE

    2014-01-01

    The life expectancy of Asphalt Binder (AB) has been negatively impacted by the harsh bombardment of UV rays. UV rays cause asphalt to oxidize faster, which results in deterioration of asphalt rheological characteristics that can lead to pavement distresses. This study investigates the impact of bio-char and nano-clay of asphalt rheological properties. Two nano scale materials were used for this study were nano-clay and bio-char. Nano-clay (Cloisite 30B) is a naturally occurring inorganic mine...

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

    Directory of Open Access Journals (Sweden)

    William Andrés Castro López

    2016-01-01

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

  8. Laboratory and field evaluation of hot mix asphalt with high contents of reclaimed asphalt pavement

    Science.gov (United States)

    Van Winkle, Clinton Isaac

    Currently in Iowa, the amount of RAP materials allowed for the surface layer is limited to 15% by weight. The objective of this project was to develop quality standards for inclusion of RAP content higher than 15% in asphalt mixtures. To meet Superpave mix design requirements, it was necessary to fractionate the RAP materials. Based on the extensive sieve-by-sieve analysis of RAP materials, the optimum sieve size to fractionate RAP materials was identified. To determine if the higher percentage of RAP materials than 15% can be used in Iowa's state highway, three test sections with 30.0%, 35.5% and 39.2% of RAP materials were constructed on Highway 6 in Iowa City. The construction of the field test sections was monitored and the cores were obtained to measure field densities of test sections. Field mixtures collected from test sections were compacted in the laboratory in order to test the moisture sensitivity using a Hamburg Wheel Tracking Device. The binder was extracted from the field mixtures with varying amounts of RAP materials and tested to determine the effects of RAP materials on the PG grade of a virgin binder. Field cores were taken from the various mix designs to determine the percent density of each test section. A condition survey of the test sections was then performed to evaluate the short-term performance.

  9. Magnesium oxychloride cement concrete

    Indian Academy of Sciences (India)

    A K Misra; Renu Mathur

    2007-06-01

    The scope of magnesium oxychloride (MOC) cement in concrete works has been evaluated. MOC cement concrete compositions of varying strengths having good placing and finishing characteristics were prepared and investigated for their compressive and flexural strengths, -values, abrasion resistance etc. The durability of MOC concrete compositions against extreme environmental conditions viz. heating–cooling, freezing–thawing, wetting–drying and penetration and deposition of salts etc were investigated. The results reveal that MOC concrete has high compressive strength associated with high flexural strength and the ratio of compressive to flexural strength varies between 6 and 8. The elastic moduli of the compositions studied are found to be 23–85 GPa and the abrasion losses between 0.11 and 0.20%. While alternate heating–cooling cycles have no adverse effect on MOC concrete, it can be made durable against freezing–thawing and the excessive exposure to water and salt attack by replacing 10% magnesium chloride solution by magnesium sulphate solution of the same concentration.

  10. Evaluation of asphalt enhanced with locally made nanomaterials

    Directory of Open Access Journals (Sweden)

    HELAL EZZAT

    2016-08-01

    Full Text Available This research work focused on the investigation of the properties of asphalt binder modified with different percentages of nanoclay (NC and nanosilica. The nanosilica was manufactured from two different sources: silica fume (NSF and rice husk (NSH. Results showed that NSF tends to decrease the penetration and increase the softening point temperature (SFT and rotational viscosity (RV. However, NC content more than 3% was found to increase the penetration and decrease both RV and SFT. Using smaller percentages of NC increased both SFT and RV and decreased the penetration. Up to 3% of NSH exhibited improvement in penetration, SFT, and RV, however slight or no improvement was observed at higher contents. The Dynamic Shear Rheometer (DSR results showed obvious improvement in the Superpave performance grade. Both NSF and NC were found to improve Marshall stability of the asphalt mixtures.

  11. Integrated coke, asphalt and jet fuel production process and apparatus

    Science.gov (United States)

    Shang, Jer Y.

    1991-01-01

    A process and apparatus for the production of coke, asphalt and jet fuel m a feed of fossil fuels containing volatile carbon compounds therein is disclosed. The process includes the steps of pyrolyzing the feed in an entrained bed pyrolyzing means, separating the volatile pyrolysis products from the solid pyrolysis products removing at least one coke from the solid pyrolysis products, fractionating the volatile pyrolysis products to produce an overhead stream and a bottom stream which is useful as asphalt for road pavement, condensing the overhead stream to produce a condensed liquid fraction and a noncondensable, gaseous fraction, and removing water from the condensed liquid fraction to produce a jet fuel-containing product. The disclosed apparatus is useful for practicing the foregoing process. the process provides a useful method of mass producing and jet fuels from materials such as coal, oil shale and tar sands.

  12. New method to quantitatively evaluate the homogeneity of asphalt mixtures

    Institute of Scientific and Technical Information of China (English)

    WU Wen-liang; ZHANG Xiao-ning; WANG Duan-yi; LI Zhi

    2009-01-01

    To evaluate the homogeneity of asphalt mixtures, the images of sections obtained by cutting the as-phah mixtures specimen horizontally or vertically were analyzed with digital image processing techniques, and the particle area ratio was achieved by applying sector scan for horizontal specimen and vertical scan for vertical one. The research result indicates that the influence of random distribution of aggregates in cutting the specimen can be eliminated by using colored aggregates to distinguish coarse and fine aggregates and using color threshold to segment the images. Choosing three typical gradations, proving particle area ratio obeying normal distribution and using the variability of particle area ratio as an index, it is feasible to quantitatively evaluate the homogenei-ty of asphalt mixtures.

  13. Investigation of thermal properties of raw materials of asphalt mixtures

    Science.gov (United States)

    Géber, R.; Simon, A.; Kocserha, I.

    2017-02-01

    Asphalt mixtures are composite materials, which are made of different grades of mineral aggregates and bitumen. During the mixing process mineral materials were blended with bitumen at relatively high temperature (∼200 °C). As the binding process come off in these higher temperature range, thermal properties of asphaltic materials are important. The aim of this project is to reveal the thermal properties of raw materials. During our research two types of mineral aggregates were tested (limestone and dolomite) by different methods. Differential thermal analysis, thermal expansion and thermal conductivity were investigated at technologically important temperatures. The results showed that the structure of mineral materials did not change at elevated temperatures, expansion of samples was neglible, while thermal conductivity changed by temperature.

  14. Viscoelastoplastic constitutive model for creep deformation behavior of asphalt sand

    Institute of Scientific and Technical Information of China (English)

    叶永; 杨新华; 陈传尧

    2008-01-01

    A uniaxial viscoelastoplastic model that can describe whole creep behaviors of asphalt sand at different temperatures was presented.The model was composed of three submodels in series,which describe elastoplastic,viscoelastic and viscoplastic characteristics respectively.The constitutive equation was established for uniaxial loading condition,and the creep representation was also obtained.The constitutive parameters were determined by uniaxial compression tests under controlled-stress of 0.1 MPa with five different test temperatures of 20,40,45,50 and 60 ℃.Expressions of the model parameters in terms of temperatures were also given.The model gave prediction at various temperatures consistent with the experimental results,and can reflect the total deformation characterization of asphalt sands.

  15. Evidence of Multi-Stage Hydrocarbon Charging and Biodegradation of the Silurian Asphaltic Sandstones in the Tarim Basin, China

    Institute of Scientific and Technical Information of China (English)

    刘洛夫

    2002-01-01

    Asphalts distributed widely in the Silurian sandstones of the Tarim Basin include dry asphalt, soft asphalt and heavy oil. These asphaltic sandstones underwent multi-episodic sedimentary and tectonic events, and their occurrence is diverse and complex, being mixed with normal oil usually. So far, very little work has been done on the asphaltic sandstone origin and hydrocarbon charging ages. After detailed study on the Silurian sandstones, the following highlights were obtained from the analytical results: distribution of the mixed asphalt, heavy oil and normal oil in the Silurian sandstones is the result of multi-stage hydrocarbon charging from the Lower Paleozoic marine source rocks; the characters of asphalts formed from oils of different charging ages are of difference; the most important process constraining.the asphaltic sandstone origin is thought to be biodegradation.

  16. Structural Design of Asphalt Pavement for Low Cost Rural Roads

    Institute of Scientific and Technical Information of China (English)

    Yuan Goulin; Chen Rongshen

    2006-01-01

    On the basis of the equivalent axle load action frequency, the traffic classifications of rural roads as well as their corresponding types are classified. The asphalt pavement structure, road surface types and thickness of the rural roads are suggested for the various action frequency of the equivalent axle load. Furthermore, the roadbase thickness graphs are provided according to different equivalent axle load action frequency with different roadbed modulus and road surface modulus taken into account.

  17. The Research on the Cracks of the Asphalt Pavement

    Directory of Open Access Journals (Sweden)

    OuYangZiqiang

    2015-07-01

    Full Text Available The cracking is one of the common diseases of the asphalt pavement. According to the shape and the forming reasons, the cracks can be divided into two categories. Each categories can be divided into several types. Through the comparison and the analysis of the causes of different cracks, the prevention and the treatments are proposed in the respects of the structural design, material design and construction

  18. The optimization of concrete mixtures for use in highway applications

    Science.gov (United States)

    Moini, Mohamadreza

    . Conducted research enabled further reduction of cement contents to 250 kg/m3 (420 lb/yd3) as required for the design of sustainable concrete pavements. This research demonstrated that aggregate packing can be used in multiple ways as a tool to optimize the aggregates assemblies and achieve the optimal particle size distribution of aggregate blends. The SCMs, and air-entraining admixtures were selected to comply with existing WisDOT performance requirements and chemical admixtures were selected using the separate optimization study excluded from this thesis. The performance of different concrete mixtures was evaluated for fresh properties, strength development, and compressive and flexural strength ranging from 1 to 360 days. The methods and tools discussed in this research are applicable, but not limited to concrete pavement applications. The current concrete proportioning standards such as ACI 211 or current WisDOT roadway standard specifications (Part 5: Structures, Section 501: Concrete) for concrete have limited or no recommendations, methods or guidelines on aggregate optimization, the use of ternary aggregate blends (e.g., such as those used in asphalt industry), the optimization of SCMs (e.g., class F and C fly ash, slag, metakaolin, silica fume), modern superplasticizers (such as polycarboxylate ether, PCE) and air-entraining admixtures. This research has demonstrated that the optimization of concrete mixture proportions can be achieved by the use and proper selection of optimal aggregate blends and result in 12% to 35% reduction of cement content and also more than 50% enhancement of performance. To prove the proposed concrete proportioning method the following steps were performed: • The experimental aggregate packing was investigated using northern and southern source of aggregates from Wisconsin; • The theoretical aggregate packing models were utilized and results were compared with experiments; • Multiple aggregate optimization methods (e.g., optimal

  19. Drying of Concrete

    DEFF Research Database (Denmark)

    Hansen, Kurt Kielsgaard; Geiker, Mette Rica; Nygaard, Peter Vagn;

    2002-01-01

    Estimated and measured relative humidity (RH) change during drying are compared for two concretes, 1: w/c=0.46 and 2: w/(c+0.5fa+2sf)=0.50. The estimations were undertaken by means of the Swedish program TorkaS 1.0. Measurements were performed by RH-sensors type Humi-Guard. Drying of 150 mm thick...... samples from sides at 60% RH and 22 °C took place from 4 to 56 days after casting. At the end of the drying period the measured RH was about 4% lower than the estimated RH at 1/5th depth from the exposed surface for both concretes. In the middle of the samples, the measured RH of concretes 1 and 2 were 2...

  20. Water Entrainment in Concrete

    DEFF Research Database (Denmark)

    Jensen, Ole Mejlhede; Hansen, Per Freiesleben

    This report gives a survey of different techniques for incorporation of designed, water-filled cavities in concrete: Water entrainment. Also an estimate of the optimum size of the water inclusions is given. Water entrainment can be used to avoid self-desiccation and self-desiccation shrinkage...... during hydration [1,26]. What is needed is some sort of container which retains the shape of the water when mixed into the concrete. The container may function based on several different physical or chemical principles. Cells and gels are examples of containers found in nature. A cell membrane provides...... a boundary to water, whereas a polymer network incorporates water in its intersticious space with its affinity due to interaction energy and polymer entropy. Such containers allow water to be stored as an entity. In relation to concrete the water encapsulation may be accomplished either before or after start...

  1. Representative volume element of asphalt pavement for electromagnetic measurements

    Directory of Open Access Journals (Sweden)

    Terhi Pellinen

    2015-02-01

    Full Text Available The motivation for this study was to investigate the representative volume element (RVE needed to correlate the nondestructive electromagnetic (EM measurements with the conventional destructive asphalt pavement quality control measurements. A large pavement rehabilitation contract was used as the test site for the experiment. Pavement cores were drilled from the same locations where the stationary and continuous Ground Penetrating Radar (GPR measurements were obtained. Laboratory measurements included testing the bulk density of cores using two methods, the surface-saturated dry method and determining bulk density by dimensions. Also, Vector Network Analyzer (VNA and the through specimen transmission configuration were employed at microwave frequencies to measure the reference dielectric constant of cores using two different footprint areas and therefore volume elements. The RVE for EM measurements turns out to be frequency dependent; therefore in addition to being dependent on asphalt mixture type and method of obtaining bulk density, it is dependent on the resolution of the EM method used. Then, although the average bulk property results agreed with theoretical formulations of higher core air void content giving a lower dielectric constant, for the individual cores there was no correlation for the VNA measurements because the volume element seizes deviated. Similarly, GPR technique was unable to capture the spatial variation of pavement air voids measured from the 150-mm drill cores. More research is needed to determine the usable RVE for asphalt.

  2. Physical and chemical characterization of asphalt (bitumen) paving exposures.

    Science.gov (United States)

    Herrick, Robert F; McClean, Michael D; Meeker, John D; Zwack, Leonard; Hanley, Kevin

    2007-01-01

    The purpose of this research was to characterize the physical and chemical properties of asphalt (bitumen) fume and vapor in hot mix asphalt roadway paving operations. Area and personal air samples were taken using real-time equipment and extractive sampling and analytical methods to determine worker asphalt exposure, as well as to characterize the properties of the particulate and vapor phase components. Analysis of personal inhalation and dermal samples by gas chromatography/mass spectroscopy showed that the polycyclic aromatic hydrocarbon profile is dominated by compounds with molecular weights below 228, and that substituted and heterocyclic polycyclic aromatic hydrocarbons comprised approximately 71% of the detectable mass concentration (vapor and particulate combined). Principal components analysis shows that the polycyclic aromatic hydrocarbons with molecular weights greater than 190 are the driving force behind the polycyclic aromatic compound exposures measured for the dermal and particulate phases; there was no clear trend for the vapor phase Most of the aerosol particles are fine (mass median aerodynamic diameter 1.02 microm; count median diameter 0.24 microm).

  3. Application of a bio-binder as a rejuvenator for wet processed asphalt shingles in pavement construction

    OpenAIRE

    2015-01-01

    This paper investigates the merits of application of bio-binder to enhance rheological properties of asphalt binder in the presence of wet processed recycled asphalt shingles (RAS). It will further examine the performance and workability of asphalt designed with and without a specified percentage of a bio-binder produced from swine manure and RAS. Bio-binder was introduced to liquid asphalt binder modified with four different percentages of RAS; the high and low temperature properties of each...

  4. Ancient concrete works

    CERN Document Server

    Sparavigna, Amelia Carolina

    2011-01-01

    It is commonly believed that the ancient Romans were the first to create and use concrete. This is not true, as we can easily learn from the Latin literature itself. For sure, Romans were able to prepare high-quality hydraulic cements, comparable with the modern Portland cements. In this paper, we will see that the use of concrete is quite older, ranging back to the Homeric times. For instance, it was used for the floors of some courts and galleries of the Mycenaean palace at Tiryns

  5. Concentrated loads on concrete

    DEFF Research Database (Denmark)

    Lorenzen, Karen Grøndahl; Nielsen, Mogens Peter

    1997-01-01

    This report deals with concentrated loads on concrete.A new upper bound solution in the axisymmetrical case of a point load in the center of the end face of a cylinder is developed.Based on previous work dealing with failure mechanisms and upper bound solutions, new approximate formulas are devel......This report deals with concentrated loads on concrete.A new upper bound solution in the axisymmetrical case of a point load in the center of the end face of a cylinder is developed.Based on previous work dealing with failure mechanisms and upper bound solutions, new approximate formulas...

  6. Electrokinetic decontamination of concrete

    Energy Technology Data Exchange (ETDEWEB)

    Lomasney, H. [ISOTRON Corp., New Orleans, LA (United States)

    1995-10-01

    The U.S. Department of Energy has assigned a priority to the advancement of technology for decontaminating concrete surfaces which have become contaminated with radionuclides, heavy metals, and toxic organics. This agency is responsible for decontamination and decommissioning of thousands of buildings. Electrokinetic extraction is one of the several innovative technologies which emerged in response to this initiative. This technique utilizes an electropotential gradient and the subsequent electrical transport mechanism to cause the controlled movement of ionics species, whereby the contaminants exit the recesses deep within the concrete. This report discusses the technology and use at the Oak Ridge k-25 plant.

  7. Emissions Reductions Associated with the Use of Warm-Mix Asphalt as Compared to Hot-Mix Asphalt

    Science.gov (United States)

    2014-06-01

    processes generating greenhouse gases. The motivation was to meet strict emissions regulations set forth by the Kyoto Protocol (Prowell et al. 2012...estimating emissions during asphalt production, current protocols to measure and control emissions, and case studies where WMA emissions were measured and...Research Program (NCHRP) funded project 9-47a to update the Protocol for Documenting Emissions and Energy Reductions of WMA and Conventional HMA

  8. 77 FR 50651 - Approval and Promulgation of Air Quality Implementation Plans; New Hampshire; Hot Mix Asphalt Plants

    Science.gov (United States)

    2012-08-22

    ... Mix Asphalt Plants AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: EPA... Hampshire Hot Mix Asphalt Plant Rule at Env-A 2703.02(a). This rule establishes and requires limitations on visible emissions from all hot mix asphalt plants. This revision is consistent with the maintenance of...

  9. 77 FR 50608 - Approval and Promulgation of Air Quality Implementation Plans; New Hampshire; Hot Mix Asphalt Plants

    Science.gov (United States)

    2012-08-22

    ... Mix Asphalt Plants AGENCY: Environmental Protection Agency (EPA). ACTION: Direct final rule. SUMMARY... 2703.02 for hot mix asphalt plants. This rule establishes and requires limitations on visible emissions from all hot mix asphalt plants. This revision is consistent with the maintenance of all...

  10. Evaluation of Permeability of Asphalt Pavement Based on Differential Thermal Infrared of Pavement Surface%基于路表红外差热的沥青混凝土路面渗水性能评价

    Institute of Scientific and Technical Information of China (English)

    李志栋; 黄晓明; 赵洁雯; 郭辉; 许涛; 陈广秀

    2012-01-01

    因离析、荷载、自然等因素的影响,沥青混凝土路面产生密实性不均一以及渗水性能表面差异性,为了改变目前渗水仪检测效率低、代表性差等现状,能够快速、多剖面对其渗水性能进行检测评价.首先,通过试验与有限元方法分析了沥青混凝土路面表面温度及其差异度与其渗水性能的相关性;同时,优选了路表温度差异度的最佳检测方法.研究表明:路表温度差异度与渗水性能相关系数达到0.9747,与传统渗水仪的渗水系数相关性达0.8272,建立了通过红外识别路表温度差异度来检测沥青混凝土路面渗水性能的方法和相应评价标准.另外,开发了连续测速达100 km/h的沥青混凝土路面渗水性红外检测仪,与传统渗水仪相比,检测范围由点变面,效率提高80倍,费用节约58%,并与处治透水的雾封层技术实现数据信息共享.%Because of synthesis effect of the segregation, loads and climate, the densification and permeability of the surface of asphalt concrete pavement is different. To change the status that the detecting efficiency and veracity of permeability detector at present is low and the permeability can be detected quickly and multi-section,firstly, the relativity between the surface temperature difference degree and permeability of asphalt concrete pavement is analyzed by the laboratory experiments and ABAQUS elements, and the detecting way of temperature difference degree optimized. It proved that relativity of the surface temperature difference degree and permeability of asphalt concrete pavement or permeability coefficient by the permeability detector arrived to 0. 974 7 or 0. 827 2, and detecting way of asphalt concrete pavement permeability is established based on the surface temperature difference degree identified by the infrared technology. At the same time, based on this principle the first continuous infrared detector reached l00km/h ,of asphalt concrete pavement

  11. Corrosion Inhibitors for Reinforced Concrete

    OpenAIRE

    ECT Team, Purdue

    2007-01-01

    Steel corrosion in reinforced concrete structures has been a major problem across the U.S. Steel-reinforced concrete structures are continually subject to attack by corrosion brought on by naturally occurring environmental conditions. FerroGard, a corrosion inhibitor, developed by Sika Corporation, penetrates hardened concrete to dramatically reduce corrosion by 65% and extend the structure's service life.

  12. From concrete repair to concrete conservation: How to preserve the heritage values of historic concrete

    NARCIS (Netherlands)

    Heinemann, H.A.; Zijlstra, H.; Hees, R.P.J. van; Nijland, T.G.

    2012-01-01

    The conservation of historic concrete is an increasing task, challenging both concrete repair specialists and conservation specialists. In practice, too often repair strategies are followed where conservation strategies would have been necessary. The application of repair techniques poses two threat

  13. Contaminated soil concrete blocks

    NARCIS (Netherlands)

    Korte, de A.C.J.; Brouwers, H.J.H.; Limbachiya, Mukesh C.; Kew, Hsein Y.

    2009-01-01

    According to Dutch law the contaminated soil needs to be remediated or immobilised. The main focus in this article is the design of concrete blocks, containing contaminated soil, that are suitable for large production, financial feasible and meets all technical and environmental requirements. In ord

  14. Electrical pulses protect concrete

    NARCIS (Netherlands)

    Van Kasteren, J.

    2006-01-01

    Even concrete is not as hard as it looks. Sea water, salt on icy roads, and indirectly even carbon dioxide from the air can corrode the steel of the reinforcing bars and so threaten the strength and integrity of a bridge pier, jetty, or viaduct. Dessi Koleva, a chemical engineer from Bulgaria, spent

  15. Micromechanics of Concrete.

    Science.gov (United States)

    1988-01-25

    reflects the dispersion of the coarse aggregates on the mesoscale. Specifically, the experimental measure- ments indicate ( Mindess and Young 1981, Zaitsev...Mecanique des Materiaux Solides, Dunod, Paris. Mindess , S. and J. Young (1981), Concrete, Prentice-Hall Inc., Englewood Cliffs, NJ. Mura, T. (1982

  16. Mechanics of Concrete II

    Science.gov (United States)

    1990-10-18

    Mindess (1981) also agrees with the first of the two reactions but allows for transformation of the ettringite to monosulphate in the case when all...Comp. Materials, 23, pp. 163-194. 3 Mindess , S. and J. F. Young (1981), Concrete, Prentice Hall, Englewood Clifs, N.J. * 74 I Moavenzadeh, F.(1971

  17. Designing concrete for durability

    Directory of Open Access Journals (Sweden)

    Boyd, A. J.

    2001-12-01

    Full Text Available Some of the factors affecting the durability of modern concrete structures are discussed, with an emphasis on the problems caused by modern portland cements. This is followed by a description of some concrete durability issues of current interest, such as plastic shrinkage, seawater attack, and sulfate attack. The strategies for testing for durability are also discussed. It is concluded that, to produce durable concretes, a holistic approach to concrete construction must be adopted.

    Se discuten algunos de los factores que influyen en la durabilidad de las estructuras de hormigón modernas, haciendo énfasis en los problemas causados por el cemento Portland. A esto sigue una descripción de algunas cuestiones de interés general de la durabilidad del hormigón tales como la retracción plástica, el ataque por agua de mar y el ataque por sulfatos. Se discuten también las estrategias de los ensayos de durabilidad. Se concluye que para producir hormigones durables se debe adoptar un enfoque holístico de la construcción con hormigón.

  18. Concrete Block Pavements

    Science.gov (United States)

    1983-03-01

    1967, Cedergren 1974, Federal Highway .’,U .. V,47 -’":: 37 Administration 1980). Block pavements have essentially the same prob- lems with moisture...Vicksburg, Miss. Cedergren , H. R. 1974. Drainage of Highway and Airfield Pavements, John Wiley and Sons, New VOk. I Cement and Concrete Association

  19. Teaching concrete structures

    DEFF Research Database (Denmark)

    Goltermann, Per

    2014-01-01

    The teaching of concrete structures has been revised and a number of new approaches have been developed, implemented and evaluated. Inductive teaching, E-learning and “patches” have been found to be improvements and may be an inspiration and help for others development of the teaching and learning...

  20. Danish High Performance Concretes

    DEFF Research Database (Denmark)

    Nielsen, M. P.; Christoffersen, J.; Frederiksen, J.

    1994-01-01

    In this paper the main results obtained in the research program High Performance Concretes in the 90's are presented. This program was financed by the Danish government and was carried out in cooperation between The Technical University of Denmark, several private companies, and Aalborg University...