Modified Asphalt Samples Research Articles

Study on spinnability, thermal stability and microstructure of modified isotropic pitch by adding polyacrylonitrile melt blending

Asphalt samples modified by melting isotropic asphalt with polyacrylonitrile (PAN) are obtainable. Investigations were conducted on the spinnability, microstructure, and thermal stability of the modified asphalt. The results demonstrate that pan40w modified asphalt possesses the highest spinnability stability. Additionally, there is a reduction in viscosity within the smooth range, a slight increase in the flow point, and an enhancement in spinnability. Compared to other modified asphalt samples, PT403 containing 0.3 % PAN exhibited the highest comprehensive performance, characterized by a molecular weight of 400,000, enhanced spinnability, a larger and more uniform microcrystal size, and improved thermal stability. This study employs a distinctive modification scheme and provides a cogent explanation of the corresponding mechanisms, potentially contributing to the advancement of producing cost-effective pitch-based carbon fibers from petroleum by-products.

Thermal Behaviour of Cool-Pavement Materials Development using Palm Oil Shell Aggregate

Cool-pavement technology has emerged as a potential solution to environmental issues posed by the urban heat island phenomenon, with surface temperature acting as a vital parameter in the evaluation of its thermal performance. This study focuses on the thermal performance results of modified asphalt concrete mix, wherein palm oil shell (POS) serves as a replacement for fine aggregate. Modified asphalt samples prepared using the Marshall Mix Design, with varying degrees of fine aggregate substitution (0%, 10%, 20%, 30%, 40%, and 50%), underwent a 24-hour continuous surface temperature measurement over a span of 20 days, under real-world tropical climate conditions. The findings demonstrated that sample P5, comprising 50% fine aggregate substitution, exhibited the highest reduction in surface temperature when compared to control sample P0, registering a significant decrease of up to 3.29°C during the period of peak solar intensity. ANOVA test-based statistical analyses confirmed significantly lower temperatures for all test samples, barring sample P1 (10% aggregate replacement), relative to the control sample. The results highlight the efficacy of POS as a fine aggregate substitute in asphalt concrete, significantly lowering asphalt pavement surface temperature, thereby endorsing the potential use of POS-modified asphalt in cool-pavement applications.

Emission reduction effect of eco-friendly asphalt modified with isocyanate-nanoclay composites

The environmental and health issues associated with the generation of fumes during hot mix asphalt used in road construction necessitate the exploration of cleaner production methods. This study investigated the viability of utilizing isocyanate-nanoclay composites as modifiers for eco-friendly modified asphalt. The composite modified asphalt samples were prepared by adding isocyanate (isophorone diisocyanate, IPDI) and nanoclay (organic montmorillonite, OMMT or attapulgite, ATT) to the base asphalt at varying contents. A device for generating and collecting asphalt fumes was developed. The impact of modifier dosage on fume emission reduction was assessed quantitatively and qualitatively using ultraviolet–visible spectrophotometry and gas chromatography-mass spectrometry, yielding the optimal ratio of composite modifiers. The fume emission reduction mechanism of the modifiers was elucidated by analyzing changes in distribution, functional group composition and micromolecular spacing of asphalt using fluorescence microscopy, fourier-transform infrared reflection, and X-ray diffraction. Results revealed that the intercalation effect between nanoclay and asphalt, combined with chemical reactions between isocyanates and functional groups of nanoclay/asphalt components, effectively impeded the escape of fume molecules. Modified asphalt with 3% ATT+3% IPDI achieved an impressive fume emission reduction rate of 44.67% and enhanced basic performance of base asphalt. The findings contribute to the development of cleaner production methods for hot mix asphalt, thus paving the way for sustainable and safer construction practices in the future.

Compatibility of PCM modified asphalt based on naphthenic oil modification: A multiscale study

In this study, the compatibility of phase change material(PCM) in asphalt was investigated using several methods. Initially, solubility parameters, radial distribution functions, and relative concentrations of PCM modified asphalt were examined through molecular simulations to explore its compatibility. Subsequently, the phase structures of different PCM modified asphalt were analyzed using fluorescence microscopy experiments on both upper and lower samples. Finally, the compatibility differences among PCM modified asphalt samples with varying naphthenic oil contents were evaluated through softening point and Brookfield viscosity tests. The results indicate that higher naphthenic oil content in encapsulated PCM leads to closer solubility parameter alignment with the base asphalt. At a naphthenic oil content of 50% in encapsulated PCM, significant interactions occur between PCM and asphalt components. The concentration distribution curve of PCM molecules in the asphalt approaches 1.0, indicating excellent compatibility between encapsulated PCM and asphalt. Overall, the results from fluorescence microscopy and conventional tests are consistent with simulation outcomes. The only discrepancy observed is that conventional experimental results for the PCM-60% sample slightly outperform those for the PCM-50% sample.

Optimization and characterization of composite modified asphalt with pyrolytic carbon black and chicken feather fiber

Abstract Asphalt is a vital construction material for roads, and its properties can be enhanced by modification. In this study, a composite modified asphalt was developed using pyrolytic carbon black (PCB) and chicken feather fiber (CFF). Box–Behnken design of response surface methodology was employed to optimize the preparation parameters, and the optimal parameters were determined to be a PCB dosage of 15% (weight ratio), a CFF dosage of 0.3% (weight ratio), and a chicken feather (CF) shear time of 8.2 min. A Dynamic Shear Rheometer (MCR302) was used to analyze the high-temperature rheological properties of the modified asphalt samples, and the results showed that the addition of PCB and CFF enhanced the high temperature performance and anti-aging performance of the asphalt. The rheological properties at high temperature increased progressively with the increase in CFF dosage. The Bending Beam Rheometer (BBR) test was conducted to evaluate the low-temperature rheological property of PCB/CFF composite modified asphalt, which was observed to decrease with the increase in CFF dosage. The microscopic properties and the chemical group of 15% PCB + 0.3% CFF with 8.2 min CF shear time composite modified asphalt (0.3%PC-MA) were analyzed using Fourier Transform Infrared spectrometer and Fluorescence Microscopy, and the results indicated that PCB and CFF were physically blended with asphalt without undergoing a chemical reaction, and they were well compatible with and evenly distributed in asphalt. Finally, the high- and low-temperature performances, as well as water stability, of the base asphalt (BA), 15% PCB dosage modified asphalt (P-MA), and 15% PCB dosage modified asphalt with x% CFF dosage with a shear time of 8.2 min (PC-MA) were compared. The addition of CFF significantly enhanced the high-temperature and low-temperature performances, as well as water stability of P-MA mixtures. The aim of this study is to provide a laboratory test basis for the application of PCB/CFF composite modified asphalt.

Peanut Shell Powder as a Sustainable Modifier and Its Influence on Self-Healing Properties of Asphalt.

This paper investigated, for the first time, the feasibility of using peanut shell powder, a plant waste residue, as a modifier for asphalt, particularly its self-healing ability. Modified asphalt samples were prepared using varying particle size ranges and concentrations of peanut shell powder. Various tests, including fatigue-healing-fatigue tests, high- and low-temperature rheological property tests, penetration tests for conventional performance, and atomic force microscopy scans, were conducted to investigate the effects of peanut shell powder on the self-healing performance and other properties of asphalt. The results showed that the porous structure of peanut shell powder was able to absorb light components within the asphalt and release them under load, thus improving the self-healing and fatigue resistance properties of the modified asphalt. Experimental conditions such as temperature, healing time, and fatigue damage level also influenced the self-healing performance of asphalt. Additionally, peanut shell powder could increase the dynamic viscosity and high-temperature rheological property of modified asphalt while reducing its temperature susceptibility. However, it had a negative impact on the low-temperature ductility and creep rate, which could potentially lead to premature cracking of asphalt pavement in colder regions. Increasing the content of peanut shell powder and reducing its particle size within a certain range had positive effects. When the content of peanut shell powder was 4% and the particle size range was 80-100 mesh, the overall performance of modified asphalt was satisfactory.

Comparative analysis of rheological and microscopic performance of SBS modified asphalt based on field aging and laboratory aging

In this study, the correlation and difference of Styrene-Butadiene-Styrene (SBS) modified asphalt rheological and microscopic performance under field aging and laboratory aging were analyzed. The asphalt recovery experiment obtained SBS modified asphalt after construction aging (CA), 1 year field aging (1A), and 5 years field aging (5A) as field aging samples. The SBS modified asphalt samples were obtained by laboratory aging methods: ultraviolet aging (UV), rotating film oven test (RTFOT), and pressure aging vessel (PAV). Dynamic shear rheometer (DSR) and bending beam rheometer (BBR) experiments were applied to test the SBS modified asphalt rheological performance, and infrared spectroscopy (IR) and fluorescence microscopy (FM) were applied to test the SBS modified asphalt microscopic performance. By contrasting the SBS modified asphalt correlation and difference in rheological and microscopic performance during field aging and laboratory aging, the conclusion demonstrates that the degree of rheological and microscopic performance after CA treatment is not significantly different from that after RTFOT treatment. However, from the micro performance analysis, the micro performance indexes of PAV (10H) and PAV (20H) were significantly lower than those of 1A and 5A, and the rheological and micro properties are different after accelerated aging. This suggests that accelerated aging can recover and simulate the behavior in the early stages of field aging, but with increasing age, accelerated aging cannot fully simulate the aging behavior in more complex situations, resulting in a lower degree of accelerated aging than in the mid- to late-stage field aging.

Evaluating the Performance and Fume Suppression Effect of Tourmaline-Modified Asphalt

Abstract This study prepared samples of fume-suppressing asphalt to improve the eco-friendly characteristics of pavement construction. Various quantities and mesh sizes of tourmaline powder were used in modified asphalt samples. The conventional performance test, multiple stress creep recovery test, linear amplitude sweep test, and bending beam rheometer test were used to analyze the asphalt’s properties at high, medium, and low temperatures, and the fume suppression effect was evaluated using a homemade asphalt fume generation and enrichment device. The study’s results indicate that as the mesh size and quantity increased, the penetration of the modified asphalt decreased, the softening point increased, and ductility first increased before decreasing. The larger the mesh size and tourmaline quantity, the better the improvement effect of the tourmaline powder on the asphalt’s high- and low-temperature performance. Tourmaline powder has a good inhibitory effect on the release of asphalt fume, and when the quantity of tourmaline powder at 800 mesh and 1250 mesh exceeded 16 % of the base asphalt, the change rate significantly influenced the fume suppression rate. Overall, the influence of tourmaline powder on the performance and fume suppression of asphalt was highest when the quantity was 14 % with 1250 mesh.

Evaluating the High-Temperature Properties and Reaction Mechanism of Terminal Blend Rubber/Nano Silica Composite Modified Asphalt Using Activated Rubber.

Terminal blend (TB) rubberized asphalt is a popular technology in the production of rubberized asphalt. However, it always presents challenges regarding the inadequate high-temperature rutting performance of the binders. Additionally, crumb rubber (CR), a modifier of asphalt is a cross-linked material which presents poor compatibility between CR particles and bitumen. Incorporating nanomaterials and pretreating CR particles are two possible solutions to address this drawback. But the performance improvement and modification mechanism of the composite TB binders is not clearly understood. Therefore, the purpose of this research was to evaluate the high-temperature properties and reaction mechanism of the TB rubber/nano silica composite modified asphalt using microwave activated rubber. To achieve the research purpose, bitumen penetration grade 80-100 was first modified with 8% CR particles at elevated temperature to produce TB rubberized asphalt followed by the addition of 0.5, 1.5 and 3.0% weight percentage of nano silica to produce TB rubber/nano silica composite modified asphalt. Short and long-term aging tests were performed on samples by thin film oven test (TFOT) and pressure aging vessel (PAV) prior to chemical and rheological tests. The results of the study shows that nano silica has a great influence on the high temperature rutting resistance, storage stability and anti-aging properties of TB rubberized asphalt. Nano silica promoted good interaction and compatibility between CR particles and bitumen and improved the overall rheological properties of the binders. XRD test results revealed that the TB rubberized/nano silica composite modified asphalt samples were amorphous materials and did not have a crystalline structure. The reaction mechanism between rubber and asphalt was found to be physical, whereas nano silica interacted chemically with TB rubberized asphalt. In light of these findings, this research concluded that nano silica evidently improves the high-temperature rutting properties of TB rubberized asphalt, which deserves further exploration and application.

Multi-scale studies on interfacial system compatibility between asphalt and SBS modifier using molecular dynamics simulations and experimental methods

• Interfacial model of asphalt/SBS modifier is established based on molecular dynamics method; • Representative indexes are proposed to evaluate interfacial compatibility between asphalt/SBS; • The compatibility between asphalt/SBS at the preparation temperature of 170 °C is better one; • The interaction and aggregation between aromatics/SBS are conductive to their compatibility; • Asphalt with more aromatics and less asphaltenes is easier to improve compatibility with SBS. To understand the interfacial property and its effect on the compatibility between styrene–butadienestyrene (SBS) modifier and asphalt, as well as to further reveal their compatibility mechanism, the indexes of interfacial energy, relative concentration, and radial distribution function were used to discuss the interfacial property between asphalt and SBS modifier, as well as to evaluate the compatibility based on the established SBS/asphalt interface model using molecular dynamics (MD) method. Moreover, the laser scanning confocal microscope (LSCM) and scanning electron microscope (SEM) tests were also conducted on SBS modified asphalt samples prepared at the temperatures of 160 °C, 170 °C, 180 °C and 190 °C to study the compatibilities between asphalt and SBS modifier. Results indicate that the compatibility between asphalt and SBS modifier is better at the preparation temperature of 170 °C. At this point, the interfacial energy between asphalt and SBS modifier is larger than those at the other three preparation temperatures. Also, the compatibility at the preparation temperature of 170 °C is promoted by the more obvious interaction and aggregation between aromatics and SBS modifier. Additionally, both aromatics and saturates are conductive to the compatibility between asphalt and SBS modifier, while the asphaltenes are inverse. Finally, asphalt with high-content aromatics and low-content asphaltenes is proposed to use for improving the interfacial property and the compatibility between asphalt and SBS modifier, so as to prepare a high-performance SBS modified asphalt.

Effect of Thermal Oxygen Aging Mode on Rheological Properties and Compatibility of Lignin-Modified Asphalt Binder by Dynamic Shear Rheometer.

Lignin is abundant in nature. The use of lignin in the asphalt pavement industry can improve pavement performance while effectively optimizing pavement construction costs. The purpose of this paper is to study the effect of lignin on the anti-aging properties of asphalt. Commercial lignin was selected to prepare a lignin-modified asphalt binder. The properties of lignin-modified asphalt were studied by rheological experiments. The high-temperature rheological properties of two kinds of base asphalt and modified asphalt samples with different contents of lignin under three conditions of original, rolling thin film oven (RTFO) aging, and pressure aging vessel (PAV) were tested and analyzed with temperature sweep, frequency sweep, and multiple stress creep recovery (MSCR) tests. By comparing the variation laws of evaluation indicators, such as complex shear modulus G*, phase angle δ, anti-aging index, cumulative strain, and viscous component Gv, we found that lignin could effectively improve the high-temperature stability of base asphalt, but it had a negative impact on the compatibility issues of base asphalt. Meanwhile, lignin played a filling role in the base asphalt, and the increase in viscosity was the fundamental reason for improving the high-temperature stability of the base asphalt. The research results indicated that lignin could effectively improve the anti-aging performance of asphalt and play a positive role in prolonging the service life of pavement.

Experimental Investigation of the High-Temperature Rheological and Aging Resistance Properties of Activated Crumb Rubber Powder/SBS Composite-Modified Asphalt.

Crumb rubber could form the active groups on the surface by interrupting the crosslinking bond to improve the compatibility with asphalt. While styrene-butadiene-styrene block copolymer (SBS)-modified asphalt has excellent comprehensive properties, it has poor anti-aging performance and a high cost. To explore the influence of composite modification of activated crumb rubber powder (ACR) and SBS on asphalt, modified asphalt samples with different modifiers and SBS contents were prepared. Conventional physical properties tests, a dynamic shear rheometer (DSR), and the thin-film oven test (TFOT) were used to study the conventional physical properties, high-temperature rheological properties, and aging resistance of asphalt. In addition, the action forms and distribution of modifiers in asphalt were observed by an optical microscope to characterize the micro-morphology of ACR/SBS composite-modified asphalt. Test results showed that after adding SBS, the softening point, ductility, and elastic recovery of ACR/SBS asphalt could be significantly improved, but the viscosity and softening point difference were also larger. At the same time, according to the complex shear modulus, phase angle, and rutting factor, SBS can effectively improve the high-temperature deformation resistance of ACR/SBS asphalt. The modified asphalt (ACR/SBS-2) had good high- and low- temperature performances, as well as an appropriate viscosity and low softening point difference, as a research object of aging. After short-term aging, the changes in the high- and low-temperature performances and workability of ACR/SBS asphalt were reduced. Taking the softening point as the target performance, the softening point of ACR/SBS asphalt was less affected by aging time and temperature, indicating that ACR/SBS asphalt was not sensitive to aging temperature and had good stability and aging resistance. From the micrograph by microscope, it was found that ACR/SBS asphalt could maintain a relatively stable polyphase structure for aging resistance.

Internet of Things (IoT) and Remote Sensing (RS) Based on Geospatial Information System (GIS) Against Fatigue of Asphalt Bitumen

This work investigated the Geospatial Information System (GIS) as a low-cost, high-precision, and rapid method for identifying the (RAP). This work also showed that (GIS) can be linked to new techniques including Remote Sensing (RS) and the Internet of Things (IoT) which can be serious subjects for research in the field of pavement engineering. The results of the present work showed that Remote Sensing (RS) has reduced fatigue and thermal cracks. Moreover, for modified asphalt samples, tests of Marshall stability, flow, resilience modulus, repeated load axial, uniaxial creep and indirect tensile fatigue were carried out.

The effect of sea salt solution erosion on cohesion, chemical and rheological properties of SBS modified asphalt

This paper aims to explore the damage mechanism of asphalt under sea salt erosion environment from the aspects of surface physics, chemistry, and rheology. To simulate the sea salt erosion environment, styrene–butadiene–styrene (SBS) modified asphalt samples were soaked with mixed salt solutions containing sodium chloride (NaCl) and sodium sulphate (Na2SO4) at six different concentrations. The effect of sea salt solution erosion on cohesion, chemical and rheological properties of SBS modified asphalt was studied through surface free energy (SFE) test, Fourier transform infrared spectroscopy (FTIR) analysis and Dynamic Shear Rheometer (DSR) test, respectively. The results indicate that the salt in the mixed salt solution migrates into the asphalt samples, resulting in the decrease of the total SFE, cohesion work. While the appearance of the new absorption peaks and the changes of peak area ratio of characteristic peaks indicate that the salt migrates into the asphalt sample, reacts with the asphalt, and leads to the aging of asphalt simultaneously. Besides, the viscous component of asphalt decreases, while the elastic component and the Superpave rutting parameter increase, indicating that elastic recovery ability and rutting resistance of the SBS modified asphalt are enhanced. Moreover, the changes of phase angle and complex modulus of rheological master curves at low frequency domain, as well as the increase of failure temperature and the Glover-Rowe parameter, indicate that the high temperature properties of asphalt are improved, while the cracking resistance is damaged. Finally, all the above indexes have linear relationships with the concentration of mixed salt solution.

Penentuan Stabilitas Penyimpanan Aspal Modifikasi Berbasis Karet Alam Padat Jenis Crumb Rubber

The development of road infrastructure in Indonesia is very rapid to keep pace with the growth of vehicles. However, the structure of road pavements in Indonesia is not optimal and causes various problems due to overload and Indonesia's climate. Therefore, it is necessary to increase the performance of asphalt binders with additives such as natural rubber or better known as natural rubber modified asphalt. This study examines the effect of natural rubber content (crumb rubber standard Indonesian rubber 20), sulfur additive content, storage temperature, and storage time on the phase stability of natural rubber modified asphalt. Making crumb rubber modified asphalt samples begins with the mastication of crumb rubber in an open mill. Next, crumb rubber was melted at 200°C and mixed in asphalt with 8, 10, and 12% levels. The last stage is to test the stability of modified asphalt storage at a temperature of 160°C for 48 hours. The results showed that modified asphalt with various levels of rubber experienced storage stability problems after 48 hours. The addition of sulfur additives did not significantly affect storage stability. The optimum addition of natural rubber at 10% crumb rubber content with the difference in softening point (Tbottom – Ttop) reached 11.6°C.

Rheological evaluation of asphalt binder modified by amorphous poly alpha olefin (APAO)

This study examined the effect of amorphous poly alpha olefin (APAO) on the rheological behavior of asphalt binder. In order to modify asphalt binder, several percentages of APAO (0, 2, 4, 6, 8%, and 10% by the weight of asphalt binder) were used. The penetration grade, softening point, ductility, and viscosity tests were performed. Also, the multiple stress creep recovery (MSCR) and linear amplitude sweep (LAS) tests were conducted to evaluate the rutting and fatigue behavior of asphalt binder. The storage stability test was implemented to measure the ability of modified asphalt binder against separation. Based on the results, using APAO reduced the penetration grade and increased the softening point due, maybe, to the asphalt binder stiffening. The PI values increased with the addition of APAO, which indicated that the temperature susceptibility of all modified asphalt samples was reduced compared to the base asphalt binder. The increase in the viscosity of virgin asphalt binder due to APAO addition caused the mixture placement/compaction operations to become harder. The G*/sinδ parameter for all types of pre-post-aging RTFO asphalt binders was improved for APAO-modified asphalt binder, meaning that the latter stiffened and thus increased the respective rutting resistance of mixtures. The low-temperature performance of asphalt binder indicated that the stiffness of asphalt sample increased with an increase in the APAO percentage, which indicates that the addition of APAO improved the cracking potential of modified asphalt binders and had negative effects on the asphalt binders. The storage stability test results indicated that the phase separation of asphalt binder was related to the APAO content. Results revealed, ignoring the levels of stress, that using APAO reduced the non-recoverable creep compliance (Jnr) value of virgin asphalt binder, indicating the production of an asphalt binder benefitting higher rutting resistance with APAO modification. APAO increased the %R of asphalt binder. Based on the LAS test results, the addition of APAO led to an increase in the fatigue life of asphalt binders, and by increasing the additive content, the fatigue life increased. The FTIR analysis indicated that no chemical interaction was observed between asphalt binder and APAO.

Evaluation for Low Temperature Performance of SBS Modified Asphalt by Dynamic Shear Rheometer Method

Finding an alternative or supplementary test method to evaluating the low temperature performance of asphalt is an area of considerable interest. This paper tries to explore the possibility of using the dynamic shear rheometer (DSR) method for assessing the low temperature properties of styrenebutadienestyrene (SBS) modified asphalt. In the study, 60/80 and 80/100 pen grade asphalt binders, named binder A-70, binder B-70 and binder C-90, are used to produce the SBS modified asphalt samples. After that, the low temperature performance of the asphalt binders is characterized by using bending beam rheometer (BBR) test. The results indicate that the low temperature performance of the different binders is related to the source of the binder. The low temperature performance of asphalt could be improved with the addition of the SBS. The DSR test is used to develop the complex modulus master curves for binders. Based on the principle of time–temperature conversion, the glass transition temperature of asphalt is calculated by the Williams–Landel–Ferry (WLF) equation. The glass transition temperatures (Tg) of base asphalt and the SBS modified asphalt are determined by the viscoelastic parameters of the master curve and the WLF equation coefficients based on the time–temperature superposition principle. By establishing the relationship between the critical temperature and the Tg of the asphalt binder, the effectiveness of the method established in this paper is verified. The advantage of this method is the ability to use the DSR test for the rapid evaluation of the low temperature performance of asphalt, which is able to reduce testing materials and save testing time as well. The glass transition temperature of the SBS modified asphalt is closely associated with aging degree, asphalt source and the SBS content.

Mixed Plastic Wastes as a Promise Path to Green Roads

Abstract In this study, asphalt binder was loaded with 5%, 10%, 15% and 20%wt of grinded mixed waste of plastics. The plastic waste comprised mainly from a mixture of PE/EPDM (60/40 wt.%), . To study the effect of these wastes on asphalt binder performance; the physical properties of asphalt binder were studied including penetration, viscosity, and softening point. The mechanical characteristics of modified asphalt binder were studied using dynamic mechanical analyzer (DMA). Two types of sweep tests were conducted on virgin and modified asphalt binder to study the effects of temperature and frequency on binder performance. Elastic recovery of modified asphalt binder was also investigated using the stress relaxation mode in DMA. In addition, the fatigue properties of modified asphalt samples were estimated from the obtained data of loss modulus and rutting factor (G*sinδ). It is observed that mixed plastic waste positively enhances the performance of asphalt binder.

Cellulose Microfibril and Micronized Rubber Modified Asphalt Binder

Cellulose microfibrils (CMFs) and micronized rubber powder (MRP) can be derived from low or negative-cost agricultural/industrial waste streams and offer environment-friendly and cost-effective pathways to develop engineering products. This study investigated the efficacy of adding these micromodifiers on the performance characteristics of asphalt binders. In this work, samples were produced using a mixture of slow-setting anionic asphalt emulsion with various combinations of MRP (at 0, 2 and 10 wt %) and four types of CMFs (hydrophobic and hydrophilic with crystalline ratios of 86% and 95%) at 0, 2 and 5 wt %. The performance of modified asphalt samples was assessed by penetration depth (PD), softening point (SP), and penetration index (PI). Linear regression analysis showed that adding CMFs and/or MRP reduced PD and increased SP values. The type of CMFs significantly affected the performance, which becomes more distinct with the increased weight content of CMFs. While hydrophilic CMFs caused increases in SP and PI values, no clear trend was seen to determine the effect of CMF crystallinity. It was also discovered that the combined addition of CMF and MRP achieved similar PI values at lower total weight content compared to using MRP alone.

Evaluation the Physical Properties and Marshall Stability for Asphalt Modified with Waste Polypropylene and Nanosilica Powder

Recently, Nanotechnology was being widely accepted in many fields due to its unique properties in enhancing the characteristics of many different kinds of materials, including asphalt binder. On the other hand, the usage of polymer nanocomposites for the production of durable asphalt mixtures has steadily replaced the use of polymer-modified binders. This study investigates the influence of nanosilica particles (NS) on rheological properties and mixture performance of asphalt modified with 2% waste polypropylene polymer (WPP). IN laboratory work, NS/WPP composite modified asphalt samples have been produced by adding three different percentages of NS particles (0.5, 1, and 2%) by weight of binder and 2 % WPP to control asphalt (60-70) penetration grade using a mechanical mixer and a homogenizer shear mixer with shear rate 27000 rpm for 10 min at mixing temperature (165 ±5) °C. The physical tests and Marshall stability were used to evaluate the NS/WPP composite modified asphalt binder properties and mixtures performance characteristics. This study found that 2 % of NS particles decrease the temperature sensitivity of WPP modified asphalt by 13% due to improving the hardness of the NS/WPP composite modified binder. The results also showed that the Marshall stability values of NS/WPP composite modified asphalt mixtures improved by 34.2% and 9.71% at 2 % NS compared with the control and WPP modified asphalt mixtures respectively. This suggests that the composite NS/WPP composite has a noticeable effect on the performance of the flexible pavement, thus increase paving’s service life.