Properties Of Binders Research Articles

The performance evaluation of extracted asphalt binder from dry process produced rubber modified asphalt mixture

Limited research studied the influence of rubber on asphalt binder in the dry process rubberized asphalt mixture. By using the extraction procedure, the asphalt binder interacted with rubber could be obtained and assessed. The goal of the research is to evaluate the accurate characteristics of asphalt binder from dry process rubberized asphalt mixture and determine the interacted rubber percentage in dry process rubberized asphalt mixture. Four extracted and two laboratory prepared asphalt binders were compared. The rheological performance, creep and recovery, and low temperature characteristics of different were evaluated with the dynamic shear rheology, multiple stress creep and recovery, and asphalt binder cracking device tests, respectively. The rubber modification and aged binder from the RAP enhanced the high temperature characteristics of the asphalt binder. Rubber modification increased the elastic property and deformation resistance of the asphalt binder and decreased the stress sensitivity of the asphalt binder. The coupling effect of aged asphalt binder and rubber addition enhanced the permanent deformation resistance of the asphalt binder to sustain heavy stress load. The aged binder from RAP deteriorated the low temperature characteristics of the extracted asphalt binder. The base asphalt binder with rubber had a better ability to dissipate the stress in the asphalt binder due to the decrease in temperature. The interacted rubber percentage was estimated by comparing the rutting parameter and percent recovery, and the estimation results based on the DSR and MSCR test had a good correlation. The interacted rubber percentage in the two types of rubber modified mixtures are 61.9% and 57.4%, respectively.

Impact of Modified Post-Consumer Plastic (MPCP) Toner on Asphalt Binder Properties

The utilization of recycled plastics in asphalt pavements has become increasingly popular because of its potential benefits for the environment and economy. Prior studies have concentrated on incorporating high- and low-density polyethylene into asphalt mixtures as an additive to enhance their rheological and mechanical properties. Nevertheless, new techniques have surfaced for utilizing post-consumer plastics (PCP) that cannot otherwise be recycled. One example of PCP is toner, an electronic waste that is challenging to recycle but contains polymeric components such as styrene-acrylate, styrene-butadiene, and polyester, making it a promising candidate for modifying asphalt binders. This research explores the feasibility and potential of modified post-consumer plastic (MPCP), predominately composed of toner, as an additive to improve asphalt binder performance and address issues such as rutting and low-temperature cracking. The research employs Superpave performance grading, phase separation, frequency sweep, and multiple stress creep and recovery testing to assess the effectiveness of different MPCP dosages. The results indicate that MPCP-modified asphalt binders exhibit increased stiffness and viscosity proportional to the MPCP content, resulting in improved resistance to permanent deformation. However, a 20% MPCP dosage level significantly increases phase separation and adversely affects the low-temperature performance grade (PG), while a 10% MPCP dosage does not affect PG. The research recommends limiting MPCP dosage to 10% for optimal storage stability, increased stiffness, improved rutting resistance, and minimal changes in cracking resistance. Overall, this study provides insights on the effective use of MPCP in asphalt binders and the potential influence on the performance of asphalt concrete mixtures.

Recycling of calcined low-grade limestone slurry in producing low carbon cementitious binder towards sustainable environment: ANOVA, statistical modeling & microstructural performance

Conventional cement production is a significant contributor to greenhouse gas emissions; consequently, there is a growing interest in developing eco-friendly alternatives. This study focuses on the optimization of low graded calcined limestone to create a new type of cementitious binder that has a lower environmental impact. The research involves several experiments to evaluate the physical and mechanical properties of cementitious binder, including consistency, setting time, compressive strength, flexural strength. Along with this, statistical modeling and parametric optimization was done by Box Behnken Design (BBD) of Response Surface Methodology (RSM). The results suggest that the optimized cementitious binder has comparable properties to the conventional cement and can be used as a sustainable alternative. Results revealed that 28- days compressive strength of 49.25 MPa was achieved with the incorporation of 24% fly ash, 3.36% silica fume, 14% low grade calcined limestone slurry and 13% low grade uncalcined limestone slurry to the mortar. This study provides valuable insights for the development of new and eco-friendly construction materials, which can reduce the environmental impact of the building industry. Life cycle assessment revealed that low clinker composite mortar with low grade calcined and uncalcined limestone slurry reduced the CO2 emission by 41.39% and cost reduced by 22.80%.

An atomistic model of aged asphalt guided by the oxidation chemistry of benzylic carbon with application to asphalt rejuvenated with a triglyceride

Waste cooking oil (WCO) shows promise for restoring physical properties of aged asphalt binder to enable pavement recycling. Its use as a rejuvenator lessens the environmental burden on land fills with its disposal. In this study, we report our initial development of an aged asphalt model and the computational investigation of the effect of triglycerides, the main component of WCO, on the viscosity, self-diffusion, and microstructural properties of aged asphalt at 1 atm and 404 K. The fundamental research question in this work involves understanding the underlying mechanism(s) by which WCO rejuvenates aged asphalt binder. A central feature of this aged asphalt model is consideration of oxidation chemistry and reported functional group concentrations since properties like viscosity are known to be related to the amounts of moieties such as ketones and sulfoxides. Model oxidation compounds include proposed representative asphalt structures based on Peterson’s dual reaction pathways, leading to polycyclic aromatic hydrocarbon molecules resulting from fast phase aromatization and multiple species from a slow phase degradation of benzylic hydroperoxide intermediates. The new model takes into account the observed product distribution of aryl alcohols and aryl ketones based on findings for cumene oxidation in the literature. Other oxygen-containing functional groups, such as anhydrides, carboxylic acids, and polynuclear aromatics, have been incorporated to account for the critical physical characteristics of aged asphalt. By extending the molecular basis set of asphalt components, we can now construct more realistic asphalt models to represent varying SARA (Saturates, Aromatics, Resins, Asphaltents) content, different oxidation levels and functional group composition. Virtual representations of the molecules in the basis set were created and molecular dynamics simulations of the aged asphalt model conducted. Results with aged asphalt basis set provided good agreement with reported physical properties. With the developed aged asphalt model, our molecular dynamics simulations reveal that triglyceride (tristearin) has preferential interactions with asphaltene molecules. On addition of 10 wt% triglyceride to aged asphalt, the asphaltene-asphaltene interaction was most significantly affected. The radial distribution functional analysis revealed that the asphaltene-asphaltene nearest neighbor distance increased from 4.0 Å to 7.5 Å. Thus, adding triglyceride to aged asphalt helps to reduce the aggregation of asphalt components and as such promotes a decrease in viscosity of the aged asphalt, from 83 cP to 69 cP. In addition, the asphaltene components have larger self-diffusion coefficients upon the addition of triglyceride, changing from 3.57 × 10−8 cm2/s in the aged asphalt to 1.41 × 10−7 cm2/s in the triglyceride/aged asphalt mixture. Those findings are consistent with the observed effectiveness of utilizing waste cooking oil to rejuvenate aged asphalt.

Effect of Sodium Silicate to Hydroxide Ratio and Sodium Hydroxide Concentration on the Physico-Mechanical Properties of Geopolymer Binders

Geopolymers are emerging materials in the construction industry that are yet to achieve uniform standards in their mode of synthesis. Several factors over the years are said to affect the performance of the binders which vary widely. This paper investigates the effect of silicate-to-hydroxide ratio and sodium hydroxide concentration on the mechanical properties of metakaolin-based geopolymer binders. Four SS/SH ratios of 0.5, 1.0, 1.5, and 2.0 and four SH concentrations of 8M, 10M, 12M, and 14M were studied with the kaolin calcined at 800oC. Physical and mechanical tests were conducted on sixteen (16) samples at testing ages of 7, 14, and 28 days. The mean density of the geopolymer binders was 1.86 g/cm3, and the samples increased with increasing SS/SH ratio and SH molarity with the 2MK14 having the maximum density of 1.95 g/cm3. The compressive strength and flexural strength of the samples generally increased with testing age (7-28 days). The compressive strength of the samples further showed a direct increase with SS/SH ratio, though, above SS/SH = 1, the compressive strength began to decrease gradually. The maximum compressive strength for these binders 14.6MPa which was recorded by the 1MK10 sample. The Pareto chart for the compressive strength of the samples showed that both the SS/SH ratio and SH concentration contributes significantly (95% significant level) to the compressive test results. However, the SS/SH ratio had a more standardised effect on the compressive strength of the binders. The maximum flexural strength (3.45MPa) was obtained from the 1MK8 geopolymer binder, and similar to the compressive test results, strength values were obtained at the SS/SH ratio of 1

Variation and mechanism of asphalt-aggregate interface features under ultraviolet aging based on meso- and micro-observations

Time-dependent variation and mechanism of asphalt-aggregate interface features under ultraviolet (UV) aging have not yet been illustrated. This study explored the time-dependent variation and mechanism of asphalt-aggregate interface features under UV aging. To this end, six asphalt binders were chosen and subjected to different durations of UV aging, and then the variation behaviors of their cohesion-adhesion ability with the changing UV radiation time were analyzed through surface energy theory. Further, the microscopic attributes of asphalt binders experiencing the various UV aging durations were measured and their varying rules were investigated with a series of micro observations. Finally, the relationship between cohesion-adhesion characteristics and microscopic properties were illustrated and thus the variation mechanism of interfacial cohesion and adhesion were revealed by mathematical statistics and image presentation. The results showed that UV aging weakened the cohesion and multi-working adhesion of asphalt binders and the moisture stability of asphalt-aggregate systems, and overall presented a gradually strengthened influence on them with the prolonged UV radiation time, especially the UV radiation exceeded 6 days. The variation of phase morphology of asphalt binders under UV aging depended on the asphalt types and neat asphalt oil sources, and there existed a favorable linear relationship between Catana phase of asphalt binders and surface roughness. Adhesion force, function group and four components (saturate (S), aromatics (Ar), resin (R) and asphaltene (As)) also exhibited a gradually increasing variation as the UV radiation duration went on, and among which, the UV aging reduced the adhesion force of asphalt binders. Adhesion force Fad demonstrated the highest Pearson relevance with the cohesion and aqueous-condition adhesion and the moisture stability of asphalt-aggregate system, and the cohesion-adhesion properties of asphalt binders under UV aging met the multivariate linear mathematical relationship with the microscopic attributes screened, with the goodness-of-fit greater than 0.7000.

Study on accelerated aging rate of asphalt binder under multi-factors coupling conditions

The aging behavior of asphalt binder in service is complex. The accelerated aging methods commonly used in the laboratory are difficult to reproduce the aging behavior of asphalt binder in service. The purpose of this study is to develop a method for predicting the properties of asphalt binder in service. First, a multi-factor accelerating (MFA) aging method was developed to accelerate the aging of asphalt binder. Multi-scale characterization and correlation analysis were conducted on the MFA-aged asphalt binder. Then, the evaluation index of MFA aging was defined, which was used to establish the prediction equation for asphalt binder aging. Finally, the time correlation between field aging, pressure aging vessel (PAV) aging and MFA aging was constructed separately. The results show that accelerated aging of asphalt binder at atmospheric pressure and service temperature can be achieved by the coupled effect of temperature, ultraviolet light and rain. After 5-day MFA aging, the Glover-Rowe (G-R) parameter, an index for evaluating the cracking resistance of asphalt binder, was increased by 308%. The carbonyl index, an index for evaluating the content of chemical functional groups of asphalt binder, was increased by 67%. The correlation between the G-R parameter and the carbonyl index was linear, and the goodness-of-fit was greater than 0.9. The carbonyl index as a key chemical index may reflect the macroscopic properties of asphalt binder. The prediction equation for aging was established based on the carbonyl index of field-aged asphalt binder in Beijing, with reliability greater than 0.98. PAV aging for 20 h was equivalent to 1.35 years of asphalt binder service in Beijing. MFA aging method can better predict the aging time in the field. The prediction accuracy was 97.2%, which was 4.9% higher compared to that of PAV aging. MFA aging for 5 days was equivalent to about 2 years of asphalt binder service in Beijing.

Improving the performance and rheological properties of RAP binders using gilsonite/nanoclay and softer binder

One of the ways to improve the performance of asphalt containing RAP is the use of a modified softer binder, which can enhance the rheological and performance characteristics. In this study, to improve the rutting and fatigue properties of reclaimed asphalt binder (RAB), a softer binder containing vacuum tower bottom (VTB) and Gilsonite/Nanoclay (Gil/Nc) composite were used. In this regard, the behavior of modified RAP binders has been controlled and analyzed using physical, rheological, and performance criteria from a laboratory test and ANOVA statistical method. The three scenarios designed in this research included a neat binder, RAB containing a soft binder, and RAB containing Gilsonite and different percentages of Nanoclay. The results showed that the modified softer binders (MSB) due to the presence of a high percentage of asphaltene in Gilsonite cause a quasi-solid behavior with a lower decay rate against plastic strains and improve rutting resistance at high PG temperature. The results of the BBR test showed that despite the negative effect of the Gil/Nc combination on the low-temperature behavior, the presence of VTB containing significant aromatic compounds compensated this problem to a large extent. The simultaneous results of DSR and BBR tests showed that RAB25_Gil/Nc6, RAB50_Gil/Nc6, and RAB50_Gil/Nc3 binders with useful temperature ranges of 97.5 °C, 97.1 °C, and 94.2 °C have the best performance. The outcomes of the LAS test showed that MSB increases fatigue life and reduces the probability of cracking of RAB. MSB containing Nc6 performs better due to the formation of an elastic network due to the strong interaction between nanoparticles and functional groups of the binder. The statistical analysis based on the laboratory results showed that the changes in dosage of the Nc and RAB have a significant impact on the performance characteristics. According to technical and functional considerations, MSB_Gil/Nc6 combination was proposed for modification of the binder containing RAB50.

Variation of the coefficient of thermal expansion with the volume ratio of TiB2-Sialon and its influence on the overall performance of PcBN

In this study, the primary factors affecting the performance of PcBN (Polycrystalline cubic boron nitride) tool materials were investigated by high temperature/high pressure sintering through the variation of TiB2-Sialon volume ratio, the strength of TiB2-Sialon binder itself, as well as the matching of the average coefficient of thermal expansion (CTE) with cBN (Cubic boron nitride). The effects of TiB2-Sialon on the phase composition, microstructure, and mechanical properties of PcBN composites were studied by X-ray diffraction (XRD), universal testing machine, scanning electron microscope (SEM) and transmission electron microscope (TEM). The results show that the properties of TiB2-Sialon binder are analogous to those of the corresponding composites. The phase composition of PcBN composite is not affected by the change of volume ratio. It was found that prepared composite, have TiB2 rod crystals growing along the (100) plane and Sialon rod crystals growing on the (001) plane. The influence of the volume ratio of TiB2-Sialon on the mechanical properties of the composites is principally concerned with the density, mechanical properties, and thermal expansion coefficient of the used binder. The extent to which the binder matches the coefficient of thermal expansion is favorable to the strength of the composite. When the volume ratio of TiB2 to Sialon was 1:3, the hardness (25.21 GPa, 37.44 GPa) and toughness (7.09 Pa m1/2 and 7.48 Pa m1/2) of TiB2-Sialon binder/TiB2-Sialon-cBN composites reached the maximum value, and the optimal impact resistance was also achieved. The density of the binder and the composite material was maximized when the volume ratio is 1:4. The average thermal expansion coefficient of the binder hoc tempore matches comparatively with cBN, and the interface bonding is better, displaying the best flexural strength (805.30 MPa and 1059.60 MPa) and wear ratio (2005). Therefore, adjusting the volume ratio of TiB2-Sialon within a certain range is beneficial to further enhance the binder's strength and mechanical properties.

Study on effect of thermal, oxidative and ultraviolet coupled aging on rheological properties of asphalt binder and their contribution rates

ABSTRACT This paper aims to investigate the effect of different environmental conditions on the aging properties of virgin asphalt binder and evaluate the magnitude of aging on asphalt binder under different environmental conditions. The effect of thermal, oxidative and ultraviolet aging on the rutting resistance, fatigue resistance and cracking resistance of virgin asphalt binder was characterised based on rheological parameters. The contribution rate of different environmental factors to the aging of asphalt binder was quantitatively analysed. Results showed that high temperature repaired cracks in the asphalt binder caused by ultraviolet aging. The single aging factor of heat, oxygen and light had little effect on the rheological properties of asphalt binder. High temperature and oxygen would accelerate the aging effect of the asphalt binder aging process. Thermal–oxidative–UV-coupled aging had a more pronounced effect on the aging of asphalt binder than thermal–oxidative aging. The fatigue resistance of asphalt binder is more sensitive to the response of aging. The contribution rates of thermal–UV aging, UV–oxidative aging and thermal–oxidative aging were all greater than the sum of the contribution rates of the two corresponding single factors. The aging of asphalt binder was mainly due to thermal–oxidative aging when the aging temperature exceeded 80°C.

Effects of PET and RFCC on the dynamic modulus, phase angle, and complex viscosity of asphalt concrete

With economic and social development, the total amount of domestic and industrial solid waste discharged is considerable. In 2020, Vietnam generated about 2.2 million tons of plastic waste and 2 million tons of industrial solid waste. And most of them are landfilled and take a long time to decompose. This has dramatically affected the environment, costly land resources, and considerable transportation, burial, and management costs of those landfills. Therefore, many scientists have studied to recycle these wastes. There are two approaches to using recycled waste in hot mix asphalt (HMA). Waste plastic changes the properties of the asphalt binder, and solid waste replaces coarse particles in an asphalt mixture. During the research on using recycled waste for asphalt concrete, PET (Poly Ethylene Terephthalate) and RFCC (Residue Fluid Catalytic Cracking) were chosen for the study. This paper presents a study on the influence of PET (with 0.2% content in HMA) and RFCC (with 5% content in HMA) on the viscoelastic property of asphalt concrete based on dynamic modulus, phase angle, and complex viscosity values. At high temperatures, HMA using PET and RFCC exhibit complete elastic behavior (φ ≈ 50) in contrast to the viscous elastic behavior of the control sample (φ ≈ 150). Compared control sample, RFCC significantly increased the stiffness of HMA at low and high temperatures; with the dynamic modulus of HMA using RFCC increased 1.1 times at low and 1.6 times at high temperatures; the viscosity of HMA using RFCC and PET decreased 10 times and 7 times at low temperatures.

Quantifying the Degree of Binder Availability in Recycled Asphalt Mix Design Using White and Black Rock Mixes

Quantifying recycled asphalt binder availability in recycled asphalt pavement (RAP) mix design is very essential, as the widely adopted 100% RAP binder availability assumption in RAP mix design never holds correct. Depending on the mix production condition, recycled binder stiffness, and virgin binder properties, the degree of binder availability in the mix is always partial. The present study proposes a simple procedure to estimate the degree of recycled binder availability in RAP mix design. In the proposed methodology, the designer needs to compare optimum binder content of bituminous mixes prepared using white rock aggregate gradation and virgin aggregates, along with mixes designed by blending black rock gradation and virgin aggregates blended in proportion to achieve the target white rock gradation. The binder content in the RAP fraction used in the blending exercise was determined using ignition oven method. RAP mix designs were performed for RAP material collected from two different sources, and design was performed for three mixing durations in a laboratory pug mill—60, 120, and 180s. The mixes were prepared with 50% RAP incorporation level. RAP material was conditioned at 110°C for 2 h, whereas virgin aggregates were superheated to 175°C. Using the methodology proposed, RAP binder availability was found to vary between 92.5% and 96.6% for softer RAP material, 75.9% to 91.5% for mixes incorporating stiffer RAP. With increasing mixing time, even though the total active binder content did not change significantly, a mixture performance test quantified the implication of increased RAP binder availability in mixes. A higher degree of binder activation resulted in mixes being rut resistant, while the same mixes exhibited relatively higher cracking susceptibility.

Evaluation of Asphalt Binder and Mixture Properties by Incorporation of Waste Plastics

The improper disposal of waste materials, such as plastics, presents a severe environmental problem. However, an innovative approach to address this issue involves incorporating these waste products into asphalt. This not only improves the characteristics of the asphalt binder but also offers an efficient and responsible method for disposing of these materials. The purpose of this study is to investigate the effects of adding different amounts of polyethylene terephthalate and low-density polyethylene to a 60/70 penetration grade bitumen. Several tests were performed to determine the performance of modified asphalt binder. Binder adhesion and moisture resistance were evaluated using rolling bottle test and pneumatic adhesion tensile test. Comprehensive laboratory test results showed that the binder modified with low-density polyethylene and the control binder both had lower adhesion and moisture resistance compared to the binder containing 12 percent polyethylene terephthalate. This finding suggests that incorporating polyethylene terephthalate into asphalt binder enhances its adhesive properties and makes it more resilient against moisture. Not only does this innovative approach address the environmental issue of improper waste disposal, but it also improves the overall performance of asphalt. By effectively utilizing waste materials, such as polyethylene terephthalate, in the production of asphalt, contribute to a more sustainable and eco-friendly infrastructure.

Effects of Polyethylene Glycol/Porous Silica Form-Stabilized Phase Change Materials on the Performance of Asphalt Binders.

The road performance and temperature-regulating properties of asphalt binders modified with novel polyethylene glycol (PEG)/porous silica (PS) form-stabilized phase-change materials (PEG/PS-fs-PCMs) were studied. PS and PEG were used as the supporting substance and PCMs. The results showed that PEG/PS-fs-PCMs could maintain a maximum weight percentage of 70% without leakage, at temperatures as high as 90 °C. The PEG/PS-fs-PCMs exhibited stable chemical structures, excellent thermal stability, high heat storage density, and suitable phase-change temperature. Based on conventional physical tests, the addition of PEG/PS-fs-PCMs can increase the viscosity and the degree of hardness of asphalt binders; thus, achieving an excellent comprehensive performance of the modified asphalt binder depends on determining the optimal dosage of PEG/PS-fs-PCMs. Additionally, incorporating PEG/PS-fs-PCM particles into the asphalt binder can enhance its ability to withstand permanent deformation at elevated temperatures, while PEG/PS-fs-PCMs mainly act as a filler, weakening the cohesive force of the asphalt molecules, and preventing the ductility of asphalt from expansion, according to DSR and BBR tests. Moreover, the use of PEG/PS-fs-PCMs can enhance the heat transfer properties of the asphalt binders, resulting in an improved temperature regulation performance. However, the accumulation of PEG/PS-fs-PCM particles on asphalt binders can negatively impact the storage stability of the modified asphalt binders, because of the difference in density between the two materials.

Calcium silicate/polyvinyl/chitosan/alginate-based bioceramic slurry for 3D printing of scaffolds: Interfacial interactions – Mechanical properties relationship

At present, there are few studies investigating the influence of mechanical properties of binders on bioceramic slurry at the micro- and macroscopic levels. In this work, we used molecular dynamics (MD) simulations and experiments to investigate the influence of mechanical properties of polyvinyl alcohol (PVA), chitosan (CS), and sodium alginate (SA) polymers on calcium silicate (CSi, CaSiO3)/binder bioceramic slurry and to choose the most suitable binders to prepare CSi/binder slurry. It was found that PVA demonstrated excellent stiffness, ductility, toughness, solubility, and low shear thinning. The formation of large number of hydrogen bonds (HBs) at the CSi/PVA interface results in strong interfacial bonding and higher compressive strength of CSi/PVA slurry while other binders suffer low solubility, higher shear thinning, poor stiffness, and ductility problems. From the calculated mechanical parameters, interfacial binding energy, and compressive tests, it was found that the slurry prepared by CSi and 10 PVA (mixing ratio: 1:0.9) demonstrate the best mechanical properties, a compressive strength of 7.3 MPa, thus, meeting the requirements of compressive properties of cancellous bone defects. The simulation results were supported by experiments. This study provides a theoretical and experimental guide for binder selection in bioceramic slurry and the design of future binder composites.

Effect of Multiple Aging-Rejuvenating Cycles (MARC) on critical rheological and fatigue properties of asphalt binder

A variety of recycling agents are widely applied today to restore and enhance the physical and rheological properties of reclaimed asphalt binders (RAB). Whereas the effectiveness of these recycling agents is significantly affected by their composition and the degree of aging of asphalt, it remains unclear if they are actually restoring the whole original binder properties, or only some of the critical properties. In addition, there remains important questions about repeated recycling and how much these agents can in fact continue to restore the critical performance-related properties of the repeatedly recycled binders. Therefore, multiple aging-rejuvenating cycles (MARC) test is specially designed and the changes of G*, phase angle, and fatigue properties of asphalt binders after repeated PAV aging and subsequent additions of selected recycling agents that vary significantly in composition are investigated. In this paper, the rheological properties of asphalt and the fatigue-LAS test are used to quantify the critical properties at different aging stages and recycling agents. Results show that while the recovery of G* is possible for all agents, it is more challenging to restore the phase angle by the recycling agents used. Furthermore, results demonstrate that the recycling agents have limited capacity for restoring fatigue life at high strain level after repeated aging. The findings raise concerns about the future of repeated recycling and highlight the need to evaluate more than the LVE properties, and to sort out the changes in phase angle from the G* in order to understand the effect of these recycling agents. Additionally, for recycling agents, the performance in each cycle will change in MARC. Compared with bio-oil, it is risky to directly utilize re-refined engine oil bottom (REOB) with aged asphalt because of its invalidation after MARC.

Investigating the properties of asphalt binder modified by high- and low-density polyethylene polymer and nano-silica

This paper describes nano-silica (NS) reinforcement effects on the properties of an asphalt binder modified by 5% of low density polyethylene (LDPE) and high density polyethylene (HDPE) polymers. NS was added at 0, 2, 4 and 6% of modified asphalt weight and some physical, rheological, chemical and microstructure of the binders were evaluated. Results show adding NS into the polymer modified binder (PMB) results in better dispersion of polymer in the binder, improvement of elastic recovery and storage stability, decrease of temperature susceptibility, decrease of ductility, and slightly improvement in rutting resistance. Statistical analysis revealed that the polymer type has significant effect on SHRP rutting parameter at 76°C, elastic recovery and storage stability. It was also found that the effect of NS content is significant on the penetration, penetration index, viscosity temperature sensitivity (VTS) and storage stability.

Influence of epoxy resin polymer on recycled asphalt binder properties

Utilization of high-performance pavement materials with a high reclaimed asphalt pavement (RAP) content is gradually gaining importance given the impetus of green environmental policies. Epoxy resin polymer (EP) can greatly enhance the reuse of RAP materials in asphalt mixture. The influence of EP on the properties of aged asphalt binder was investigated wherein mechanical and chemical properties, and the micro-morphology of binders composed of aged asphalt binder and EP were also evaluated. EP significantly improved tensile, high-temperature, low-temperature, and fatigue properties of aged asphalt binder, and simultaneously reduced concentration of sulfoxide and carbonyl of aged asphalt binder. Increasing EP content reduced the impact of asphalt ageing degree on mechanical properties, micro-morphology, and chemical composition. Furthermore, the construction allowance time of the binder was increased with increasing EP content. At 40% EP content, an effective network structure was formed in the aged asphalt binder, leading to higher tensile elongation, high-temperature rheological properties, and fatigue life as compared to virgin asphalt binder. Meanwhile, low-temperature modulus and sulfoxide and carbonyl concentrations were lower than those of virgin asphalt binder. For application, a recommended EP content of 40% is suggested.

The Effects of Nano-silica Addition on the Physical Properties of Polyethylene-Modified Asphalt Binder and the Mechanical Properties and Durability of Asphalt Mixtures

The Effects of Nano-silica Addition on the Physical Properties of Polyethylene-Modified Asphalt Binder and the Mechanical Properties and Durability of Asphalt Mixtures

Characteristics of Waste Oil-rejuvenated RAP Bitumen: An Experimental Study

In recent years, Reclaimed Asphalt Pavement (RAP) has become very popular in pavement construction due to its benefits to the economy and the environment. The present study investigates the feasibility of employing Waste Cooking Oil (WCO) and Waste Engine Oil (WEO) as rejuvenators blended with reusable asphalt binder through physical and rheological properties at high and intermediate temperatures. Examined conventional properties of WCO-and WEO-modified bitumen include softening point, penetration, ductility and viscosity. In addition to these rheological properties, they also include Amplitude Sweep, Frequency Sweep, Multiple Stress Creep Recovery (MSCR), Linear Amplitude Sweep (LAS) and High-temperature Performance Grading (HTPG) tests carried out by Dynamic Shear Rheometer (DSR). The experimental outcomes revealed that both WCO and WEO could reduce deformation resistance and improve stiffness, workability and viscous behavior of aged bitumen. Moreover, the addition of waste oils improves the fatigue lives of rejuvenated bitumen and enhance fatigue cracking resistance, but at the cost of rutting resistance. Overall, WCO performs better in restoring stiff binder properties than WEO as per rheological testing. KEYWORDS: Dynamic shear rheometer (DSR), Reclaimed asphalt pavement (RAP), Rejuvenators, Waste cooking oil (WCO), Waste engine oil (WEO).