Mix Asphalt Research Articles

Effect of coordination number of particle contact force on rutting resistance of asphalt mixture

Optimizing asphalt mix design at the indoor stage is of significant importance for enhancing the rutting resistance of asphalt mixture, which is affected by its structural characteristics. In this work, the coordination number of particle contact force (CNpcf) was proposed as an indicator to represent contact characteristics of skeleton structure aggregates in asphalt mixture. Nine asphalt mixtures with different gradations were designed, and the relationship of CNpcf with the number of aggregate contact zones (CZ) was established by combining rutting tests and digital image processing technique (DIP). The Mann-Whitney U test was implemented to analyze the distribution properties of inter-particle contacts before and after the rutting test. In addition, the resistance to the further expansion of rutting was analyzed. The results revealed a significant positive correlation (PCCs = 0.843, R2 = 0.711) between CNpcf and CZ. The content of coarse aggregates in the dominant structure did not exhibit monotonic related to anti-rutting performance of the asphalt mixture. Therefore, an optimum aggregate content of 57% was utilized. The Mann-Whitney U test revealed that the mesoscale skeleton structure of the asphalt mixes before and after rutting exhibited excellent stability. This study further indicated the applicability of combining CNpcf to adjust the mix design to enhance the rutting resistance of asphalt mixture and to prevent rutting expansion in flexible pavement.

Asphalt Mixing Performance Evaluation at Province Road Junction Sta 1+700 - 2+300

Asphalt mixture is a very important component that needs to be taken into account in flexible pavement construction to achieve the durability of a highway construction. In order to achieve the durability of road construction, it is necessary to control the quality of the mixture used to determine the quality of the mixture used in road construction. Evaluation of the mixture is carried out in the laboratory to check asphalt content, aggregate gradation and field density which must meet the required tolerances for the working mixture (JMF). Evaluation of the asphalt mixture can be done by the extraction method. The extraction method used in this study is the centrifugal extraction method. With this extraction method, the composition of a mixture can be known so that it can be compared with the mixture required in the Job Mix Formula (JMF). In conclusion, there is a decrease in the extracted asphalt content with the planned asphalt content, that is, with an average asphalt content value of extraction results of 6. 58% while the planned asphalt content value is 7.10% with the required tolerance of ±0.3%. In addition to the value of asphalt content, the field density also decreased from that which was planned in the work mix. It is known that the density value in the work mixture is 2,250 g/mm3 while the average field density value is 2,095g/mm3 so that the Job Standard Density (JSD) value is 93.108% and this value is below the tolerance limit. Then the aggregate gradation of the semi-gap HRS WC mixture at the Intersection section of the Lito province on average underwent a gradation change, namely a decrease in the percentage of passing on each sieve.

Vibration-Based Smart Sensor for High-Flow Dust Measurement.

Asphalt mixes comprise aggregates, additives and bitumen. The aggregates are of varying sizes, and the finest category, referred to as sands, encompasses the so-called filler particles present in the mixture, which are smaller than 0.063 mm. As part of the H2020 CAPRI project, the authors present a prototype for measuring filler flow, through vibration analysis. The vibrations are generated by the filler particles crashing to a slim steel bar capable of withstanding the challenging conditions of temperature and pressure within the aspiration pipe of an industrial baghouse. This paper presents a prototype developed to address the need for quantifying the amount of filler in cold aggregates, considering the unavailability of commercially viable sensors suitable for the conditions encountered during asphalt mix production. In laboratory settings, the prototype simulates the aspiration process of a baghouse in an asphalt plant, accurately reproducing particle concentration and mass flow conditions. The experiments performed demonstrate that an accelerometer positioned outside the pipe can replicate the filler flow within the pipe, even when the filler aspiration conditions differ. The obtained results enable extrapolation from the laboratory model to a real-world baghouse model, making it applicable to various aspiration processes, particularly those involving baghouses. Moreover, this paper provides open access to all the data and results used, as part of our commitment to the CAPRI project, with the principles of open science.

Features of dimentional design system for asphalt concrete mix on superpave technology and bituminous binder of pg grade determination

Introduction. This article discusses the technology of designing asphalt concrete pavements, using the Superpave method. The Superpave (SUperior PERforming Asphalt PAVEments) system was developed by the Strategic Highway Research Program (SHRP) in the USA. The aim of the program was to find new ways of designing asphalt concrete pavements that will work better at extreme temperatures and heavy traffic loads.Currently, the system of volumetric design of asphalt concrete mixtures is being actively implemented in Russian road construction industry. This is an adaptation of the American Superpave method and is being implemented in our country in the form of a series of new standards. The Superpave volumetric and functional design system in particular addresses several pavement-related problems: permanent deformation, which results from poor asphalt mix shear strength at high temperatures, and low temperature damage, which occurs when the asphalt pavement is subjected to stress exceeding the compressive and tensile strength. The elimination of the above problems is carried out due to the most reasonable selection of the components of the asphalt concrete mixture.Materials and methods. Studies of bitumen binders were carried out according to the methods laid down in the technical requirements: GOST R 58400.1-2019 Public roads. Materials binding petroleum bitumen. Technical requirements taking into account the temperature ranges of operation.The selection of the PG brand of bitumen binder using Superpave technology was carried out using the example of a polymer-bitumen binder that meets the requirements of GOST 52056-2003 PBB 90 (sample 4) and a bitumen binder obtained from tar with the addition of thermoplastic elastomer (hereinafter referred to as TEP) of the SBS type that meets the requirements of GOST 52056-2003 PBB 90 (sample 3).Results. The article provides a review of technical documentation in order to familiarize with the methodology for selecting the brand of bituminous binder for asphalt mix. In the course of the research, the technological features of the system of volumetric functional design of the asphalt concrete mixture according to the Superpave method, as well as the determination of the brand of bituminous binder, were considered. The introduction of foreign experience in road construction can contribute to the improvement and improvement of the quality of Russian roads.Discussion and conclusions. Based on the experimental data carried out in the work, it can be concluded that the goal has been achieved, namely, the brands of bitumen binder have been selected using Superpave technology that meet the requirements of GOST R 58400.1–2019 and GOST R 58400.2-2019, namely for polymer-bitumen binder (PBB 90 according to GOST 52056-2003) – PG 58-28, and on the basis of tar with the addition of SBS – PG 64-28 grade TEP, respectively.Having studied the physical and chemical characteristics of the initial reagents, as well as the results of numerous chemical experiments, brands of PG bitumen binders were selected using Superpave technology and depending on climatic conditions and transport loads GOST R 58400.1-2019 Public roads. Materials binding petroleum bitumen. Technical requirements taking into account the temperature ranges of operation and GOST R 58400.22019 Public roads. Materials binding petroleum bitumen. Technical requirements taking into account the levels of operational transport loads.

Laboratory Investigation into the Partial Replacement of Aggregates with Recycled High-Density Polyethylene in a Dense Graded Asphalt Mix

Plastic waste is a growing concern today, as landfills fill up and pollution leads to global climatic problems. Some research has been conducted on using plastics in asphalt, but the effect that high-density polyethylene (HDPE) can have in the performance of the asphalt is not understood. This research examines the impact on the moisture damage, rutting, and cracking resistance of recycled HDPE plastics as a portion of aggregates in a dense graded asphalt mix. Two types of recycled HDPE were used—flakes and pellets. Mixes with 5% by volume of recycled HDPE were designed and compared with a control mix. The results indicate that the use of recycled HDPE allowed for a reduction of 0.5% binder requirement. Tensile strength ratio testing showed that, with no anti-stripping agent, the HDPE-modified mixes had acceptable moisture resistance. Both types of HDPE-modified mixes showcased superior rutting resistance based on the flow number parameter. However, the use of HDPE decreased the cracking resistance of the mixes measured with the Illinois Flexibility Index Test at intermediate temperatures. The dynamic modulus test indicated a decrease in the stiffness of the mixes at low temperatures and confirmed the increase of the stiffness at high operating temperatures. Overall, the results indicate that the use of HDPE as partial replacement of aggregates is feasible and future research could explore balancing the performance of the HDPE-modified mix.

Electrical and mechanical behaviors of conductor asphalt concrete by the addition of steel fibers

Conductive asphalt has the potential to satisfy different multifunctional applications. Thebehavior and the electrical and mechanical properties of this asphalt concrete have been modified usingconductive additives, which can improve the durability of the asphalt mix and the service life of thepavement system. Among these additives are steel fibers. The results obtained indicate that the direct tensilestrength of bituminous mix, the resistance to cracking, the energy, and the ductility modulus are increasedwith an increase in the percentage of steel fibers. Electrical resistivity decreased with the addition of steelfibers. So it is concluded that tensile strength increases reversibly with increasing electrical resistivity.

Study on the Low-Temperature Pre-Desulfurization of Crumb Rubber-Modified Asphalt.

Waste tires can be ground as crumb rubber (CR) and incorporated into asphalt pavement for efficient resource utilization. However, due to its thermodynamic incompatibility with asphalt, CR cannot be uniformly dispersed in the asphalt mix. In order to address this issue, pretreating the CR with desulfurization is a common way to restore some of the properties of natural rubber. The main technique of desulfurization and degradation is dynamic desulfurization, requiring a high temperature that may lead to asphalt fires, aging, and the volatilization of light substances, generating toxic gases and resulting in environmental pollution. Therefore, a green and low-temperature controlled desulfurization technology is proposed in this study to exploit the maximum potential of CR desulfurization and obtain high-solubility "liquid waste rubber" (LWR) close to the ultimate regeneration level. In this work, LWR-modified asphalt (LRMA) with superior low-temperature performance and processability, stable storage, and less susceptibility to segregation was developed. Nevertheless, its rutting and deformation resistance deteriorated at high temperatures. The results showed that the proposed CR-desulfurization technology could produce LWR with 76.9% solubility at a low temperature of 160 °C, which is close to or even better than the finished products produced at the preparation temperature of TB technology, i.e., 220-280 °C.

Effect of temperature and water conditioning on noise and skid resistance of dense-graded, open-graded and gap-graded asphalt mixes

With the rapid development of the transportation industry, permeable asphalt pavement has become widely used in the construction of expressways and urban roads due to its safety, comfort, and environmental protection characteristics. However, water-temperature coupling can damage the mechanical properties of permeable asphalt mixtures. The use of high-viscosity modified asphalt can improve the water damage resistance of the mixture to a certain extent, resulting in better mechanical properties. This paper focuses on the preparation of PAC-13 mixture specimens using high-viscosity modified asphalt and the study of its noise reduction and anti-skidding properties under water-temperature coupling. SMA-13 and AC-13 are used for comparative research. The influence of water-temperature coupling on the functional characteristics of permeable asphalt mixture is analyzed through standing wave tube test and pendulum test. The results show that PAC-13 exhibits better noise reduction and anti-skidding characteristics than SMA-13 and AC-13. As the temperature increases, the skid resistance of asphalt mixtures weakens, but the noise reduction properties are less affected. Furthermore, the noise reduction and anti-skidding properties of the three mixtures are significantly damaged by the action of water, with PAC-13 being the most affected. Nevertheless, PAC-13 still exhibits the best noise reduction and anti-skidding properties.

Waste Not, Want Not: Sustainable Use of Anti-Stripping-Treated Waste Ceramic in Superpave Asphalt Mixtures

This research studied the sustainable utilization of waste ceramic in asphalt mixtures by substituting fine aggregate with treated and untreated waste ceramic produced from construction and demolition activities. To improve its adhesion to the asphalt binder and lower the moisture susceptibility of Superpave asphalt mixes, the waste ceramic was treated with a silane anti-stripping agent. The Marshall quotient (MQ), Marshall stability (MS), indirect tensile strength (ITS), retained Marshall stability (RMS), and tensile strength ratio (TSR) were used to assess the mechanical performance and moisture susceptibility of all mixes. The changes in the chemical composition, synergy, physical state, and microstructure of the studied composites were also investigated using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The results revealed that substituting fine aggregate with 50% silane-treated waste ceramics reduced permanent deformation by 46%. Moreover, integrating silane-treated ceramics reduced asphalt mixture moisture susceptibility, with an RMS value of 87.7% obtained for asphalt containing 75% treated ceramic particles. The application of a silane anti-stripping agent resulted in high adhesion between the ceramic particles and bitumen as well as the production of fewer air voids in the mixes due to the formation of strong CH aromatic linkages, as well as Si-O and Si-O-Si bonds. The possibility of employing waste ceramics in asphalt mixes as a sustainable alternative to virgin aggregates while decreasing environmental impacts and improving resource efficiency is highlighted in this paper.

Optimal pavement maintenance and management strategies for flood affected low volume rural roads

Due to the increase in urbanization and industrial development in India, there has been substantial traffic on the existing roads. This impact had increased public demand for good quality roads with better maintenance and high serviceability. Further, catastrophic events like flooding can cause damage to pavements, especially in those with granular base layers and thin asphalt mix surface layers. The degree of damage relies upon the vulnerability of the pavement to the entrance of surface water, the measure of water immersion, and the drainage quality of the pavement. The extensive literature review found limited studies on the post-flood maintenance strategy for low-volume roads by considering flood resilience. In the present scenario of changing climatic conditions, it is necessary to conduct a study on the post-flood maintenance strategy of low-volume rural roads in India. This study focuses on an approach to developing post-flood maintenance and rehabilitation strategies for flood-affected low-volume roads. Ten road stretches adversely affected by the flood were selected to fulfil the aim of the study. The post-flood maintenance strategy was determined based on the Pavement Condition Index (PCI) and deflection-based pavement performance with flood resiliency of pavement materials and budget constraints. The extensive data analysis revealed that the pavement with a cement-treated base or subbase has a longer service life and less Net Present Value (NPV) than all other alternatives. NPV is 30 to 45 for rehabilitation and 52 to 55 for reconstruction, lower than other alternatives considered in the study.

ENVIRONMENTAL IMPACTS OF USING FOAMED ASPHALT

Introduction. There has been a world-wide tendency, a global trend to reduce energy demand using a wide variety of methods. With this, on the one hand, the goal is to conserve the limited available and increasingly expensive energy carriers, and on the other hand, it is strived to reduce the emission of greenhouse gases and thereby fight against climate change. Problem statement. In the field of road construction, the most widespread manifestation of this sustainability endeavour is the goal of replacing high-energy, hot asphalt mixtures (HMA) with variants of suitable quality. It is a common experience that in this field, the so-called warm asphalt mixtures (WMA) can be the most effective solution. Purpose. The purpose of this article is to examine the environmental effects of the WMA. The authors of the article also deal with whether the type of substitute asphalt mixture does not represent a (long-term) performance reduction in the asphalt layers. Materials and methods. Environmental safety of asphalt mixing plants is a growing concern nowadays due to the high temperature of asphalt mixture production requiring a lot of energy, and resulting in much air pollutants released into the air. The comparison between hot mix asphalt (HMA) and warm mix asphalt (WMA) was performed using BEES (Building for Environmental and Economic Sustainability) 4.0 model; just now the environmental features of the two asphalt mixture types was concentrated on. (The model has also an economic element).

Assessment of Adhesion and Moisture Susceptibility of Wood Ashes modified Asphalt

Large quantities of wood ash are produced across the world and are often disposed of in landfills or open dumps, leading to land constraint and environmental problems. Although introducing wood by-products into asphalt helps enhance performance and reduce the aforementioned issues, research has been done to investigate the feasibility of using wood ashes. The purpose of this study is to evaluate how the use of wood ashes affects the performance of asphalt binder and mixes. Asphalt binder and mixes containing 1, 3, and 5 percent by content of mechanically treated wood ashes were prepared. Tests, such as the bitumen bond strength (BBS) and rolling bottle test (RBT), were used to evaluate the rheological and mechanical characteristics of the modified binders and mixes. The findings revealed that a higher concentration wood ashes significantly improved the modified materials adhesion and moisture resistance.

A review of environmental emissions from asphalt plants and paving

Asphalt is a black, thermoplastic, hydrocarbon material extracted from crude oil and widely used in road construction all over the world. In order to meet the requirements of construction technology, asphalt always needs to be heated to flow state in the process of mixing and paving, during which a large amount of asphalt fume is released. Asphalt fume is a complex mixture of inorganic compound gases, volatile organic compounds and particulate matter, which poses a serious threat to the natural environment and the health of practitioners. This review presents HMA and WMA constituents and the potential health effects of criteria and Hazardous pollutants generated from asphalt pavement construction. Hot mix asphalt (HMA) and warm mix asphalt (WMA)are a major construction materials used for highway roads, building roads, airport runways, parking, and other pavement repairs in the worldwide. During HMA construction, a considerable number of volatile organic compounds (VOCs) are generated during asphalt pavement construction, and present negative effects on workers health. Accurate identification, quantification and measurement of emissions during HMA and WMA paving operations were used to identify and quantify VOCs, SVOCs, hazardous air pollutants (HAPs) and polycyclic aromatic hydrocarbons (PAHs) in asphalt fumes during production and paving activities.

Analytical Study on the Effect of Electric Arc Furnace Dust (EAFD) on the Rutting of Asphalt Concrete Mixtures

As a byproduct of the steelmaking process, significant amounts of hazardous electric arc furnace dust (EAFD) are produced. Utilizing the solidification/stabilization technology with asphalt mix is one way to safeguard the environment from its negative effects. Rutting was used as an indicator to assess the asphalt mixture with EAFD since it is an important factor in pavement design. This study's major goal is to ascertain how EAFD affects the rutting of asphalt-concrete mixtures. To evaluate the ideal asphalt content, the Marshall test method was applied to asphalt concrete mixtures. EAFD was added to the asphalt cement in four different volume percentages as a binder addition. Then, using the Universal Testing Machine, participants were exposed to a replica of the rutting test (UTM). Experiments were conducted at 25, 40 and 55oC, and at frequencies of 1, 4 and 8 Hz. Rutting was measured for each specimen. Tests results showed that while rut depth has negative correlation with of EAFD% and positive correlation with the temperature. The use of EAFD has dual advantages, protecting the environment from the adverse impact of EAFD and reducing the cost of asphalt mix without jeopardizing the pavement performance.

Analysis of Asphalt Mixtures Modified with Steel Slag Surface Texture Using 3D Scanning Technology.

This paper investigates the use of steel slag in the place of basalt coarse aggregate in Stone Mastic Asphalt-13 (SMA-13) gradings in the early forming of an experimental pavement and evaluates the test performance of the mixes, combined with 3D scanning techniques to analyse the initial textural structure of the pavement. Laboratory tests were carried out to design the gradation of the two asphalt mixtures and to assess the strength, chipping and cracking resistance of the asphalt mixtures using water immersion Marshall tests, freeze-thaw splitting tests, rutting tests and for comparison with laboratory tests, while surface texture collection and analysis of the height parameters (i.e., Sp, Sv, Sz, Sq, Ssk) and morphological parameters (i.e., Spc) of the pavement were performed to assess the skid resistance of the two asphalt mixtures. Firstly, the results show that a substitution of steel slag for basalt in pavements is a good alternative for efficient resource utilization. Secondly, when steel slag was used in place of basalt coarse aggregate, the water immersion Marshall residual stability improved by approximately 28.8% and the dynamic stability by approximately 15.8%; the friction values decayed at a significantly lower rate, and the MTD did not change significantly. Thirdly, in the early stages of pavement formation, Sp, Sv, Sz, Sq and Spc showed a good linear relationship with BPN values, and these texture parameters can be used as parameters to describe steel slag asphalt pavements. Finally, this study also found that the standard deviation of peak height was higher for steel slag-asphalt mixes than for basalt-asphalt mixes, with little difference in texture depth, while the former formed more peak tips than the latter.

Influence of curing process on the moisture loss, mechanical and performance characteristics of cold recycled asphalt mixes

ABSTRACT Improper curing of cold asphalt mixes can result in excessive moisture that can significantly impact the performance characteristics accompanied by premature failures. The present research investigated the impact of different curing temperatures and curing periods of 100% Cold Recycled (CR) mixes stabilised with foamed and emulsified asphalt. The results show that curing regime profoundly impacts the moisture loss and rate of evolution of the CR-Mix’s stiffness properties. CR-Foam mixes resulted in a higher resilient modulus (Mr) than the CR-Emulsion mixes at most curing regime conditions. The study also confirmed that Mr of CR-Mixes with the same residual moisture content is dependent on curing temperature. Hence, it is concluded that retained moisture content may not be an appropriate criterion for curing of cold recycled (CR) layer because the stiffness achieved by the CR layer is different at different curing temperatures. It is recommended to adopt stiffness as the criterion to evaluate adequate curing.

Performance characterization of asphalt mixtures under different aging levels: A fracture-based method

This paper proposes a straightforward approach to characterize the fracture properties and fatigue life of asphalt mixtures over the service time. Since the serviceability of flexible pavements varies as they age, assessing the performance of asphalt mixes under aged conditions is essential. To investigate the sensitivity of fracture-related parameters to aging, accelerated laboratory aging, which is conditioning asphalt concrete samples in a force draft oven for different aging times (0, 3, 5, 7, and 9 days), was used. The Semi-Circular Bending (SCB) test at 25 °C was carried out on neat and activated carbon-modified samples to examine the fracture responses of asphalt mixes. First, force–displacement curves at failure were plotted. Then, fracture-related parameters (e.g., peak load, fracture toughness, strain energy, and J-integral) and damage levels corresponding to each fracture criteria were measured versus aging levels. In addition, the fatigue life ratio was determined to measure the influence of aging on the long-term performance of asphalt mixtures. To incorporate the effect of aging on the overall cracking resistance of asphalt mixtures, different fracture-related parameters versus service time were studied. Experimental findings suggest that the area under the fracture property versus service time can provide a reliable index for evaluating the long-term performance of asphalt mixtures. In addition, statistical analysis was performed to assess the impact of aging on fracture-related parameters obtained from the SCB fracture test. The proposed method was able to simultaneously factor in the fracture resistance and the rate of damage development during flexible pavement service life.

High-compactability asphalt mix design framework based on binary aggregate packing

High compactability is desired for asphalt mixtures to ensure adequate field density and, therefore, the overall quality of asphalt pavements. However, compactability is typically not considered in standard mix design procedures, and existing methods for improving compactability are largely empirical. This paper proposes a mix design framework that considers the compactability of mixtures, anchored by a rational method to adjust aggregate gradation. The method is developed based on the binary aggregate packing model. The proposed mix design is applied to modify four traditional Superpave mixtures into high-compactability mixtures, to demonstrate the concept. The proposed method is compared with two empirical methods used to adjust aggregate gradation: the maximum density line (MDL) and the Bailey method. The results show that the proposed method provides a theoretical explanation of the two empirical methods and reveals their limitations. Mechanical properties related to rutting resistance, low-temperature cracking, and structural capacity of the mixtures are checked by laboratory performance tests to validate the high-compactability mix designs. The results show that, due to their denser aggregate packing, the high-compactability mixtures outperform the traditional Superpave mixtures. Therefore, the proposed high-compactability mix design framework provides a rational and practical approach to improve the field density and the overall quality of asphalt pavements.

Rheological, Spectroscopic, and Chemical Characterization of Asphalt Binders Modified with Phase Change Materials, Polymers, and Glass Powder

Recently, asphalt modifiers have increasingly gained attention for improving the mechanical and thermal characteristics of asphalt mixtures. As a result, innovative additives are being constantly developed to achieve this purpose. However, some modifiers can significantly impact the chemical and rheological properties of the asphalt binder. This paper investigates the rheological, spectroscopic, and chemical properties of asphalt binders modified with a bio-based phase change material (PCM) and phase change material mixed with glass powder (GPCM). Two binders were investigated, PG 58-28 and PG 70-28 polymer modified asphalt binder with 3% SBS. Two different percentages of GPCM (5% and 7%) were added to PG 58-28 and PG 70-28, and 5% PCM was added to PG 58-28. The results indicated that the PCMs effectively reduced the viscosity values of the asphalt binder. Moreover, testing the modified binders using differential scanning calorimetry (DSC) showed that the PCMs released the stored heat when the melting/freezing temperature was reached. However, adding glass powder with the PCMs negatively affected the thermal properties of PCMs in the asphalt mix. In addition, considerable changes in the stiffness of the binders modified with GPCM at an intermediate temperature were obtained when tested using DSR. Finally, the TGA results revealed that this specific type of PCM would not be suitable as a hot mix asphalt (HMA) modifier as its evaporation temperature is lower than the mixing temperature HMA. However, the use of PCM in warm mix asphalt (WMA) would be a more viable option. The results showed that the evaporation temperature for the PCMs was low; therefore, the PCMs cannot be used in HMA. In addition, modified binders with PCMs and GPCM showed lower viscosity compared to the control binder. The DSR rheological analysis showed that the control binder and 5%PCM, 5%GPCM, 7%GPCM, 5%GPCM, and 7%GPCM binders had similar overall properties. However, the addition of GPCM significantly decreases the stiffness at intermediate temperatures.

Performance of Aged Asphalt Mixes Containing Waste Oil Shale Filler

Performance of Aged Asphalt Mixes Containing Waste Oil Shale Filler