Polymer-modified Asphalt Research Articles

Deterioration Analysis of Pavement Structures Incorporating Polymer-Modified Asphalt

It is well-established that structural pavement deterioration is largely influenced by the frequency and magnitude of wheel loads. Furthermore, Polymer-Modified Asphalt (PMA) has gained a widespread application in pavement engineering, as the incorporation of polymers enhances the mechanical properties and improves the overall performance of the pavement, particularly with regard to fatigue resistance. In this study, an experimental program was conducted, comprising the Beam Wheel Tracker Fatigue Test (BWTFT), the Indirect Tensile Stiffness Modulus (ITSM) test, and the Indirect Tensile Fatigue Test (ITFT), on three types of asphalt mixtures: one conventional and two polymer-modified asphalt mixtures, under various conditions. Three distinct pavement structure scenarios were assumed/created/built to perform a deterioration analysis. Subsequently, an iterative approach was developed utilizing the average stiffness reduction and stiffness modulus data obtained from the laboratory results. The findings indicated that this method allows for a more accurate simulation of pavement behavior, confirming that strain levels fluctuate throughout the lifespan of the pavement. Furthermore, the study concluded that the use of PMA provides significantly greater benefits when a deterioration analysis is conducted, compared to traditional approaches.

Performance Optimization Approach of Polymer-Modified Asphalt Mixtures with PET and PE Waste

Road infrastructure sustainability and pavement performance may be increased by using waste materials like polyethylene terephthalate (PET) and polyethylene waste (PE waste) in polymer-modified asphalt mixtures. As seen by a more pronounced rise in the softening point, which exceeds 110 °C with 8% PE waste, PET was found to improve the tensile strength, resistance to cracking, and thermal stability of asphalt mixes. PE waste also increases ductility up to 4% PE waste, beyond which the combination becomes more brittle, and dramatically decreases penetration, strengthening the asphalt’s resistance to deformation. Additionally, bitumen treated with PE waste is more workable than asphalt without PET, even though bitumen treated with PE waste had a viscosity of up to 4500 Pa. Complex shear modules decreased as the PE waste and PET content increased. PET, on the other hand, increases the binder’s overall stiffness, elasticity, and tensile strength. Nevertheless, when PET content rises, ductility steadily decreases. Previous studies concentrated on the effects of each component separately, and this paper fills this knowledge gap by investigating the combined effects of PET and PE waste. The results indicate that the highest compressive strength (7.5 MPa) was obtained with 6% PE + 2% PET, while the highest tensile strength (1.40 MPa) was achieved with a balanced mix of 4% PE waste + 4% PET. Additionally, the viscosity of asphalt is increased by PET and PE waste, enhancing its performance at high temperatures. These findings demonstrate how combining PET and PE waste improves the mechanical and thermal characteristics of asphalt, providing a balance between stiffness and flexibility, a crucial feature for durable road materials under a variety of circumstances.

The Use of Waste Low-Density Polyethylene for the Modification of Asphalt Mixture

In this study, a critical evaluation and the benefits of using a waste and a virgin polymer in an asphalt mixture are presented. The present paper is the result of a three-year research effort to find a suitable recyclate compatible with asphalt binder and setting reaction conditions in the preparation of asphalt mixtures with the mentioned recyclate. This suitable candidate was recycled low-density polyethylene (LDPE), which was produced by recycling old, worn-out bags and films. An amount of 6% of LDPE by the weight of the binder content was suggested as the best amount of the modifier. Physical tests, including penetration, softening point, and kinematic viscosity have been carried out to prove the effectiveness of the modification on the binder properties. The effectiveness of the blending process and the appropriate concentration of additives led to a homogeneous polymer-modified bitumen without any imperfections in the structure. After successful preparation under laboratory conditions, this paper describes the preparation of asphalt mixtures directly in an asphalt-mixing plant and the subsequent implementation of a verification section. The overall composition of prepared polymer-modified asphalt mixtures has been studied. An important result of this study is the preparation of the asphalt mixture with waste LDPE that meets all the technical requirements. Moreover, it has been proven that this type of waste PE is fully applicable in asphalt-mixing plants in Slovakia, with zero or minimal financial burden on construction companies to complete the construction of their production facilities. Using such a technology, we can reduce the amount of waste plastics that otherwise end up in landfill.

Sustainability of Asphalt Mixtures Containing 50% RAP and Recycling Agents

The substitution of virgin asphalt binder with reclaimed asphalt pavement (RAP) has environmental and economic merits, however, cracking susceptibility arises due to the aged asphalt binder within RAP. The objectives of this study are to (1) enhance the cracking resistance of asphalt mixtures containing 50% RAP utilizing recycling agents (RAs) derived from six petroleum-based and bio-based materials, (2) conduct an environmental impact assessment (represented by global warming potential “GWP”) for high-RAP mixtures including RAs, and (3) estimate the cost effectiveness of including high-RAP content in asphalt mixtures. Based on the RAP asphalt binder performance grade (PG), base asphalt binder PG, and RAP content, the RA contents were determined to achieve a target asphalt binder of PG 76-22. A control mixture was benchmarked for comparison, specified for high-traffic volume roads, and contained PG 76-22 polymer-modified asphalt binder. The engineering performance of studied asphalt mixtures was evaluated using the Hamburg wheel-tracking (HWT), semi-circular bend, Illinois flexibility index, Ideal cracking tolerance, and thermal stress-restrained specimen tensile strength tests. It was found that petroleum-derived aromatic oil, soy-based oil, and tall oil fatty acid-based RAs demonstrated a successful restoration of aged RAP asphalt binder without compromising the permanent deformation resistance. The 50% RAP mixtures emitted less GWP by 41% and 42.9% using petroleum- and bio-oil RAs, respectively, and achieved a 31% cost reduction compared to the control mixtures.

Evaluation of the effect of binder type and layer thickness on the performnce of open graded friction courses

To improve the long-term durability and functionality of open graded friction courses (OGFC), the Florida Department of Transportation (FDOT) investigated the use of a highly modified asphalt binder and increased thickness using Accelerated Pavement Testing (APT). A total of six test sections with combinations of two modified binder types (PG 76–22 and PG 82–22) and three lift thicknesses of 0.75 (19.05 mm), 1.25 (31.75 mm) and 2 (50.8) inches were constructed at FDOT’s APT facility. Accelerated loading was performed using a Heavy Vehicle Simulator (HVS) to evaluate the relative rutting performance of the test sections. Supplementary field and laboratory tests to evaluate tensile strength, Cantabro loss, field permeability, surface characteristics, and asphalt binder properties were also conducted. Test results indicated that the use of PG 82–22 polymer modified asphalt (PMA) binder may be beneficial to improve long-term durability of the OGFC. Thicker layers of OGFC were found to have considerably lower durability. It is recommended that the use of a highly modified PMA asphalt binder in OGFC layers be considered when raveling and other durability issues are of concern.

Performance enhancement of asphalt mixture through the addition of recycled polymer materials

Enhancing the performance of asphalt binders is essential for ensuring the long-term durability and serviceability of asphalt mixtures, as it can help reduce the frequency of maintenance and repair work, ultimately leading to the development of more sustainable transportation infrastructure. To achieve this goal, this study investigates the effects of incorporating recycled polymer materials, including reclaimed polyvinyl chloride (PVC) and polystyrene (PS) derived from household waste, into hot mix asphalt. The experimental work involved subjecting the polymer-modified asphalt binders to a range of physical tests, such as softening point, penetration, ductility, indirect tensile strength, Marshall stability, and moisture susceptibility, and the results showed that the addition of recycled polymers, with an optimal content of 4%, led to lower penetration values and higher softening point temperatures, indicating improved resistance to temperature changes. Further analysis of the asphalt mixture performance revealed several beneficial outcomes, including a decrease in flow, a boost in the asphalt mixture's resistance to moisture-induced damage, and an improvement in Marshall stability and indirect tensile strength, with the inclusion of 4% recycled polymers yielding increases in Marshall stability of 43.7% and 37.4% for PVC and PS-modified mixes, respectively, and increments in indirect tensile strength of 32.2% and 29.7% for the same mixes. The study concludes that the use of recycled polymers can effectively enhance the performance and durability of asphalt mixtures, contributing to the development of more sustainable asphalt pavement construction practices by utilizing locally available or reused materials, which could lead to the increased knowledge and application of stronger and more weather-resistant asphalt mixes, ultimately promoting the advancement of sustainable transportation infrastructure.

The phase field method coupled with molecular dynamics parameter for simulating phase separation behavior of SBS modified asphalt

Polymer-modified asphalt is a thermodynamically unstable system, in which the polymer and asphalt are prone to phase separation. Due to the inadequacy of characterization methods for phase separation, this field has not been thoroughly understood or explored. This paper introduces an innovative methodology by employing a simulation approach that couples phase-field theory with molecular dynamics parameters. Using SBS polymer-modified asphalt as an example, validate the method's applicability and establish a more precise parameter library for the phase separation field model of SBS-modified asphalt. The phase separation process of SBS-modified asphalt was simulated. In combination with fluorescence microscopy experiments, the evolution of the micro and meso-phase states of the modified asphalt over time was established and tracked. Results indicate that higher light component content and lower heavy component content in asphalt improve its compatibility. Migration coefficients and interaction parameters for the phase field model were determined, and a more accurate correction factor for the entropy contribution of SBS-modified asphalt was estimated. The phase-field model shows that higher light component content and lower heavy component content result in slower and smaller phase separation, leading to better compatibility. The combined phase field and molecular dynamics simulations accurately reproduce experimental findings from fluorescence microscopy, providing theoretical references for studying phase separation in polymers.

Laboratory Evaluation of Wear Particle Emissions and Suspended Dust in Tire–Asphalt Concrete Pavement Friction

This study aims to evaluate the tire–road-wear particles (TRWPs) and suspended dust generated based on the nominal maximum aggregate size (NMAS) of the polymer-modified stone mastic asphalt (SMA) mixtures indoors. The SMA mixtures containing styrene butadiene styrene (SBS) polymer and the NMASs of 19, 13, 10, 8, and 6 mm were used. Dust was generated from the wear of the tires and the pavement inside the indoor chamber by using the laboratory tire–road-wear particle generation and evaluation tester (LTRWP tester) developed by Korea Expressway Corporation (KEC). In this method, a cylindrical asphalt-mixture specimen rotates in the center, and a load is applied using three tires on the sides of the test specimen. During the test, a digital sensor was used to measure the concentration for each particle size. After the test was completed, the dust was collected and weighed. According to the test results, the generated TRWP emissions were reduced by approximately 0.15 g as the NMAS of the SMA mixture decreased by 1 mm. TRWP emissions decreased by 20% when using the 6 mm SMA mixture compared to the 13 mm SMA mixture. For practical application, a predicted equation of TRWP emissions estimation was developed by using the concentration of suspended dust measured by the digital sensor in the LTRWP tester. LTRWP can be used as an indoor test method to evaluate pavement and tire materials to reduce the amount of dust generated from tire and pavement wear.

Molecular Dynamics-Based Study of Graphene/Asphalt Mechanism of Interaction

This study employed molecular dynamics simulation to investigate the mechanism of action of graphene-modified asphalt. A series of molecular models of graphene-modified asphalt were constructed and validated using thermodynamic parameters. The impact of the graphene (PGR) size and number of layers on its interaction with asphalt components were examined, and the self-healing process and mechanism of action of PGR-modified asphalt were analyzed. The results demonstrated that the size and number of layers of PGR significantly influenced its interaction with asphalt components, with polar components demonstrating a stronger affinity for PGR. When the size and number of layers of PGR were held constant, the interfacial binding energy between it and ACR-modified asphalt was the highest, followed by SBS-modified asphalt, and 70# matrix asphalt exhibited the lowest interfacial binding strength. This interfacial binding strength is primarily attributed to intermolecular van der Waals interactions. Furthermore, the incorporation of multi-layer PGR can markedly enhance the mechanical properties of matrix asphalt, whereas small-sized PGR is more efficacious in improving the low-temperature performance of polymer-modified asphalt. PGR can act as a bridge between asphalt molecules through rapid heat transfer and π-π stacking with aromatic ring-containing substances, which markedly increases the free diffusion ability of asphalt molecules, shortens the healing time of asphalt, and enhances the collective self-healing performance of asphalt. This study provides an essential theoretical basis for understanding the mechanism and application of PGR in asphalt modification.

Performance Evaluation of Soybean Oil/SBR Reclaimed Asphalt and Mixtures

This study evaluated the properties of soybean oil/SBR reclaimed asphalt (SSRA). The optimal preparation method for SSRA was determined. Additionally, the feasibility of the optimal SSRA scheme was verified through asphalt mixture performance tests. With the soybean oil dosage enhanced, the penetration and low-temperature rheological performance of SSRA were improved. The incorporation of soybean oil lowered the softening point, viscosity, and rutting index of aged asphalt. The softening points of SBR-4%+Oil-7.5% and SBR-6%+Oil-7.5% were 79.4 °C and 82.9 °C, respectively. The stiffness modulus of SBR-6%+oil-10% decreased by 35.37%. When the soybean oil dosage was 10% and the SBR dosage was 6% (SBR-6%+oil-10%), the properties of RTFOT+PAV aged asphalt were restored to those of its original state. The splitting tensile strength ratio of the SBR-6%+oil-10% mixture was 89%, with a decrease of 1.5% compared to the original asphalt mixture. The SBR-6%+oil-10% mixture exhibited improved high-temperature and low-temperature service properties. The total deformation of the SBR-6%+oil-10% mixture decreased by 8.43%, while its dynamic stability increased by 22.21%. This degree of improvement compared to the original asphalt mixture was not significant. The rejuvenation of the aged asphalt and mixture performance can mainly be attributed to the soybean oil supplementing the lost lightweight components of the aged asphalt, while SBR supplemented the degraded polymers. Utilizing soybean oil as a rejuvenating asphalt agent facilitates waste material recycling. Furthermore, this study provides a new idea for the recycling of polymer-modified asphalt and reclaimed asphalt pavement.

Testing and Evaluation of Interlayer Shear Performance of Conductive Rubber Active Deicing Composite Bridge Deck Pavement Structure

Abstract To achieve real-time, sustainable, efficient, and environmentally friendly active deicing of bridge decks, a new active electric heating deicing technology based on conductive rubber as a heat source is proposed in this study. The conductive rubber was laid between asphalt layer and cement layer as the functional deicing layer, and the conductive rubber active deicing composite bridge deck pavement structure was established. The interlayer treatment method of conductive rubber active deicing composite structure was proposed. Styrene butadiene styrene–modified asphalt, PB-II type polymer-modified asphalt waterproof coating, and AMP-100 second-order reactive waterproofing coating were selected as waterproofing bonding layer. The interlayer shear performance of conductive rubber composite structure was tested and evaluated by 45° inclined shear test. Taking shear strength as the evaluation index of interlayer shear performance, the durability of interlayer shear performance of conductive rubber composite bridge deck pavement in complex environment was studied. Taking the fatigue life as the evaluation index, the interlayer fatigue resistance of conductive rubber composite bridge deck and traditional bridge deck under different stress ratios were analyzed. The results showed that shear strength between the layers of the conductive rubber active snow-melting bridge deck pavement structure using PB-II type waterproof bonding layer material was the highest, which was 0.584 MPa, and the optimum dosage was 1.5 kg/m2. Under the complex environment, the interlayer shear performance of conductive rubber composite bridge deck pavement decreases, which could still be maintained at about 70 % and had certain durability. Under the same interlaminar shear stress, the interlaminar shear fatigue life of the conductive rubber active snow-melting bridge deck was reduced by about 34 % compared with the traditional bridge deck. The research results can provide a theoretical basis and data support for the structural design of conductive rubber active deicing bridge deck pavement and the selection of waterproof bonding layer materials.

Research on the Performance and Modification Mechanism of Gutta-Percha-Modified Asphalt.

Presently, there is a significant focus on the investigation and advancement of polymer-modified asphalt that is both high-performing and environmentally sustainable. This study thoroughly examined the performance and modification mechanism of gutta-percha (GP) as a novel asphalt modifier. The investigation was conducted using a combination of macro- and microscopic testing, as well as molecular dynamics simulations. This work primarily examined the compatibility of GP with asphalt molecular modeling. This paper used molecular dynamics to identify the most suitable mixing temperature. Next, the gray correlation theory was used to discuss the most effective method for preparing gutta-percha-modified asphalt (GPMA). The macro-rheological tests and microscopic performance analysis provided a full understanding of the impact of GP on asphalt properties and the process of alteration. The findings indicate that eucommia ulmoides gum (EUG) exhibits good compatibility with asphalt, while sulfur-vulcanized eucommia ulmoides gum (SEUG) does not demonstrate compatibility with asphalt. Both EUG and SEUG enhance the thermal stability and resistance to deformation of asphalt at high temperatures, with SEUG having a particularly notable effect. However, both additives do not improve the resistance of asphalt to cracking at low temperatures. The manufacturing method for EUG-modified asphalt (EUGMA) involves physical mixing, whereas sulfur-vulcanized eucommia ulmoides gum-modified asphalt (SEUGMA) involves physical mixing together with certain chemical processes. This research establishes a theoretical foundation for the advancement of GP as a novel environmentally friendly and highly effective asphalt modification.

Advancing Sustainability and Performance with Crushed Bottom Ash as Filler in Polymer-Modified Asphalt Concrete Mixtures.

Amid the growing demand for sustainable pavement solutions and the need to incorporate recycled materials into construction practices, this study explored the viability of using crushed thermal power plant bottom ash as a filler in polymer-modified asphalt concrete mixtures. Conventional lime filler was replaced with bottom ash at varying levels (0%, 25%, 50%, and 75%), and the resulting mixtures were evaluated using several performance tests. The optimal replacement level was determined to be 25%, based on the results of the indirect tensile strength (ITS) test. Comparisons between the control mixture and the 25% bottom ash-modified mixture were conducted using the dynamic modulus test, Cantabro test, Hamburg wheel tracking (HWT) test, and tensile strength ratio (TSR) test. The findings indicate that the 25% bottom ash-modified mixture demonstrated improved performance across multiple parameters. The HWT test showed enhanced rut durability, with a recorded depth of 7.56 mm compared to 8.9 mm for the control mixture. The Cantabro test results revealed lower weight loss percentages for the modified mixture, indicating better abrasion resistance. The dynamic modulus test indicated higher resilience and stiffness in both high- and low-frequency stages. The TSR test highlighted improved moisture resistance, with higher TSR values after 10 wet-drying cycles. These improvements are attributed to the fine particle size and beneficial chemical composition of bottom ash, which enhance the asphalt mixture's density, binder-aggregate adhesion, and overall durability. The results suggest that incorporating 25% crushed bottom ash as a filler in polymer-modified asphalt concrete mixtures is a viable and sustainable approach to improving pavement performance and longevity.

Comparative analysis of several short-term aging simulation methods and their impact on long-term aging performance of asphalt binders

The aging of the asphalt pavement is an essential factor to consider when constructing a road. Several methods, such as the Thin Film Oven Test (TFOT) and Rolling Thin Film Oven Test (RTFOT), have been used to simulate the short-term aging of asphalt binders. Based on the wide use of polymer-modified asphalt binder and the idea of research facilitation, 5 hours of Pressure Aging Vessel (5 h PAV) was proposed as an alternative to previous short-term aging methods of asphalt binders. However, the efficacy of this technique still needs to be wholly explored in all aspects and requires advanced research. The frequency sweep, temperature sweep, and Multiple Stress Creep Recovery tests were performed to evaluate the high-temperature performance of asphalt binders under aging conditions. In addition, the relaxation test was carried out to determine the low-temperature stress relaxation change and the fatigue cracking resistance of asphalt binders. The Chemical test explored the chemical change of asphalt binders under different aging conditions. The findings revealed that, in the case of neat asphalt binders N50, N70, and N90, the maximum disparity between the aging conditions of TFOT and 5 h PAV was found to be below 6 %. However, the difference between the aging conditions of 5 h PAV and RTFOT was observed to be approximately 20 %. Then, 5 h PAV can be highly recommended as an alternative to replacing TFOT. For SBS and high viscosity-modified asphalt binders HVMA-I and HVMA-II, the maximum gap between 5 h PAV and TFOT was estimated to be approximately 19.71 %. However, the gap between 5 h PAV and RTFOT was estimated to be less than 7 %. Then, 5 h PAV can be an alternative to replace RTFOT for modified asphalt binders if necessary. This study offers a thorough explanation and dispels doubts regarding the suitability of the 5-hour PAV as an alternative for simulating the short-term aging of asphalt binders, thereby enhancing research facilitation. Furthermore, the research delineates the impact of various short-term aging simulation methods on the long-term aging properties of asphalt binders, including the variation rates between them.

The Effect of the Temperature–Humidity Coupling Cycle on the Performance of Styrene Butadiene Styrene Polymer-Modified Asphalt Mastic

To study the variation laws and effects of asphalt mastic under the cooperative interaction of different temperatures and humidities, cyclic conditions for different temperature ranges were set to conduct indoor experimental simulations of thermal–humidity coupling cycles. Firstly, the macroscopic performance changes in styrene butadiene styrene polymer (SBS)-modified asphalt mastic were evaluated by the penetration test, softening point test, ductility test, Brookfield rotational viscosity test, and double-edge notched tensile (DENT) test; then, the mechanism of performance changes was explored from the perspective of chemical composition by combining this with Fourier transform infrared spectroscopy (FTIR). The research results show that with the increase in thermal–humidity coupling cycles, SBS-modified asphalt mastic exhibited aging phenomena such as hardening and embrittlement, and its macroscopic performance deteriorated; under the same test conditions, the interval with a higher temperature difference had a greater impact on the performance of the mastic; the sulfoxide index (IS=O) of SBS-modified asphalt mastic increases after thermal–humidity coupling cycles, while the isoprene index (IB) decreases.

Effect of Simultaneous Application of Glass Fiber Reinforcement and Polymer-Modified Asphalt Emulsion on DBST’s Resistance to Aggregate Loss Using Laboratory Investigation

Double bituminous surface treatment (DBST) has been a widely utilized pavement maintenance material due to its capability to restore the surface roughness of existing pavement and provide a layer of protection against weathering, aging, and moisture. However, DBST is highly prone to aggregate loss at an early stage, which is a very common problem experienced by surface treatment. Therefore, to lessen the aggregate loss and prolong the service life of DBST, fiber additive can be incorporated to strengthen the adhesion between the asphalt emulsion and aggregates. This study investigated the performance of glass fiber-reinforced polymer-modified DBST against aggregate loss by conducting laboratory tests using typical DBST as the benchmark of the test results. Four laboratory tests were chosen to represent different loading applications on the surface of the pavement: the bitumen bond strength (BBS) test, the sweep test, the Hamburg wheel-track test (HWT test), and a one-third-scale model mobile load simulator (MMLS3) model. Furthermore, the curing time of the asphalt emulsion was considered in the BBS test and sweep test. Based on all results from the conducted laboratory tests, polymer-modified DBST with glass fiber reinforcement presented an increased resistance to aggregate loss compared with typical DBST. Moreover, it was found that a longer curing time of the asphalt emulsion, whether it was typical or modified, strengthened the surface treatment’s resistance to aggregate loss.

Evaluation of the Effect of C9 Petroleum Resin on Rheological Behavior, Microstructure, and Chemical Properties of Styrene–Butadiene–Styrene Modified Asphalt

Understanding the modification mechanism of C9 petroleum resin (C9PR) on styrene–butadiene–styrene (SBS) polymer modified asphalt properties is of significant importance. In this paper, dynamic shear rheometer (DSR), storage stability, fluorescence morphology (FM), scanning electron microscope (SEM), Fourier transform-infrared (FTIR) spectrometer, and molecular dynamic (MD) simulation were adopted to evaluate the rheological, chemical, and microstructure molecular motion state of C9PR and SBS composite modified asphalt at different aging states. The DSR storage results indicate that the addition of C9PR could improve the high-temperature property, storage stability, and temperature susceptibility. FM and SEM results indicate that the network microstructure was enhanced and the roughness between polymer resins and virgin asphalt was improved at the microscopic scale. The MD results indicate that the heterogeneity between C9PR and SBS modified asphalt was demonstrated, and the bonding energies were enhanced with the addition of C9PR. Moreover, the FTIR results indicate that new function groups were generated in addition to C9PR. In general, the addition of C9PR is a good approach to promote high-quality polymer modified asphalt (PMA) for pavement engineering.

A review of polymer-modified asphalt binder: Modification mechanisms and mechanical properties

The significant increase in the number of vehicles, traffic speed, and load has significantly reduced the lifespan of pavements and increased maintenance costs. Therefore, the incorporation of polymers into bituminous binders is imperative to enhance pavement quality and performance. Nowadays, polymer-modified asphalt binders (PMBs) play a crucial role in pavement engineering. This polymer absorbs asphalt molecules to form a network connecting the entire binder, giving it better viscoelasticity than the base asphalt. Although polymers do enhance the properties of asphalt to some extent, there are still certain limitations hindering the future development of polymer-modified asphalt, such as high costs, low resistance to aging, and poor storage stability. Additionally, there is limited literature available that reviews the advantages and disadvantages of various polymer modifiers. The aim of this paper is to conduct a systematic review that evaluates the benefits and drawbacks of different polymer types in modifying asphalt materials. This comprehensive synthesis study thoroughly examines the historical evolution of polymer modified binders (PMBs) for asphalt pavement, including selection criteria for polymers used in asphalt modification, current state-of-the-art knowledge regarding the internal structure and morphology of PMBs, evaluation methodologies for PMB properties, binder specifications specific to PMBs, recommendations based on findings, and future research. This review will not only merit research from an academic perspective, but also provide guidance for pavement engineering.

Investigating the Dynamic Creep of Polymer Modified Hot Mix Asphalt

Abstract Jordan's road network continues to deteriorate as a consequence of the continuous increase in traffic and the absence of adequate maintenance work. The primary objective of this study was to enhance HMA performance by using polymer-modified asphalt mixtures. The polymer modifier known commercially as Eastman (EE-2) was mixed with binder penetration grade (60–70) at a ratio of 12%. In order to investigate the performance of polymer, the dynamic creep, the resilient modulus and the stability-flow tests were performed. Marshall Mix design was utilized to prepare a total of 50 samples, of which 20 were used to determine the optimal binder content, and the remaining samples were used to determine the effect of EE-2 modifier on asphalt mixtures. The results showed that the optimal asphalt content was 4.57 percent and revealed that the addition of EE-2 polymer to asphalt cement contributed to the production of a variety of desirable properties. The most important indicator of these developments is increased rutting resistance. For instance, the total permanent deformation has decreased by 87% (8500 to 1000 μm). Conversely, addition of EE-2 has resulted in a threefold increase in the resilience modulus (from 3632 to 10590 MPa). Finally, effect of the EE-2 polymer on the stability was demonstrated by increasing the stability value by about 52%

Evaluation of warm mix effect in laboratory using a self-developed WMA additive Alube

In response to the problems of high mixing temperatures and energy consumption of polymer-modified asphalt mixtures in road construction, a surfactant-based warm mix additive ‘Alube’ was developed. The warm mix SBS-modified asphalt and its mixture were prepared. Their rheological performance and chemical structure were analysed by the rheological and microscopic tests. The active mixing power (P) of asphalt mixtures were examined by the variable speed mixing (VSM) test. The mixing flowability model was then established to evaluate the warm mix effect. The results indicated that the mixing flowability of asphalt mixtures obeyed the linear Bingham visco-plastic model, and the slope and intercept of the flow straight characterised the mixing viscosity and plastic limit. It is evaluated that 0.7% Alube1 and Evotherm reduced the mixing temperature of SBS-modified asphalt mixture by 14°C and 12°C, respectively. Moreover, Alube1 is suitable for a wide range of applications through warm mix asphalt technology.