Physical Properties Of Asphalt Binder Research Articles

Modifying Effect and Mechanism of Polymer Powder on the Properties of Asphalt Binder for Engineering Application.

For achieving the better modifying effect of polyurethane on asphalt pavement materials, the PUA powder modifier was prepared with fine grinding at the glass transition temperature, and polyurethane-modified asphalt (PUA-MA) with different dosages of modifier was prepared. The impact of the PUA on the physical properties of asphalt binder was studied. The modifying mechanism of PUA on asphalt was explored by investigating the thermal performance and chemical composition of asphalt (thermogravimetric analysis, differential scanning calorimetry test, and Fourier transform infrared spectroscopy). The micrograph of the interactive interface was characterized by scanning an electron microscope. Furthermore, the rheological properties of PUA-MA were also investigated and analyzed. The results indicated that the PUA had a dense structure with few pores on the surface. After mixing with asphalt, it altered the asphalt's internal structure via physical fusion and chemical reaction (carbamate formation). PUA improved the thermal stability of asphalt, enhanced the asphalt's thermal decomposition temperature, and further reduced the thermal mass loss while decreasing the glass transition temperature. The addition and dosage increase in the PUA modifier significantly improved the softening point, viscosity, complex shear modulus, and rutting factor of asphalt. Also, the PUA could improve the elastic recovery ability of asphalt and enhance the rutting resistance of asphalt at high temperatures. However, the crack resistance at low temperatures was not effectively improved (ductility and penetration decreased). When the dosage was 6-9%, PUA-MA had the best high-temperature performance, but asphalt showed poor low-temperature performance at this dosage. This study provides a theoretical reference for popularizing and applying polyurethane as an asphalt modifier in road engineering.

Physical Characterization of Modified Asphalt Binder with Differing Fly Ash Geopolymer Contents

Nowadays, the use of waste material product widely usedin the asphalt mixtures industry production duetoa cost-effective method of pavementconstruction that can decrease the consumption of natural resources and to reduce environmental pollution.This research aimed to investigate the possibility of using waste and by-product material namely fly ash geopolymer additive to influence the physical properties of asphalt binder. A series of asphalt binder laboratory tests were carried out to evaluate the properties of the 60/70 and 80/100 asphalt binder incorporating 3%, 5%, 7%, 9% and 11% of fly ash geopolymer additive. The physical properties of the binders were determined using the penetration, softening, penetration index, ductility, and rotationalviscosity respectively. The results indicated that, the fly ash geopolymer modified binder had improved the physical properties over base binder. The thermal susceptibility also improved by referring to the Penetration Index value.Overall research conclusions are that geopolymer application resulted in a potential enhancement of some of the properties of the asphalt binder and increase the performance of asphalt binder in the pavement application.

Assessing the Influence of Digestion with Micro and Nano Size Additives on the Physical Properties of Asphalt Binder

Assessing the Influence of Digestion with Micro and Nano Size Additives on the Physical Properties of Asphalt Binder

Enhancement of Physical Properties of Asphalt Binder by Using Silica Powder

One of the primary requirements for a successful pavement system can be regarded as the caliber of the road pavement. Therefore, various measures have been taken, such as improving pavement quality and structure design methods, to reduce the issues of fatigue cracks and rutting of roads. Since a few years ago, engineers have paid more attention to modifying and improving the performance of asphalt by adding various additives to improve the environment and lower the price of modified pavement mixture. Evaluation of employing modified asphalt cement at various percentages of particle size of silica powder is the main goal of this study. Three percentages of Particle Size of Silica Powder Nano silica and micro silica with 2, 4, and 6% of the weight of asphalt as a modifier for asphalt and their effect on the performance of asphalt mixtures at high temperatures. It was discovered that adding silica powder to asphalt cement would increase the softening point and viscosity and decrease ductility and penetration. Experimental results indicated that the Silica Powder positively contributed to the performance properties of asphalt.

Evaluating Modified Asphalt Binder Comprising Waste Paper Fiber and Recycled Low-Density Polyethylene

The main concept of using waste and recycled materials as modifiers for construction materials, is to improve their performance, keep the resources, and conserve the environment from pollution problems. This investigation is tended to evaluate the effect of using two different types of modifiers on the physical properties of asphalt binder. The modifiers are Recycled-Low-Density-Polyethylene (R-LDPE) polymer and waste-Paper Fiber (w-PF), they were mixed individually and collectively with neat asphalt binder. The first set of modified binders comprised neat binder with 3% R-LDPE alone, the second is comprised 0.3%, 0.5% and 0.7% of w-PF alone, while the third comprised collective modifiers of 3% R-LDPE and 0.3%, 0.5% and 0.7% w-PF. The influence of these modifiers on neat asphalt binder was evaluated in terms of penetration (Pen.), softening point (SP), penetration index (PI), ductility, rotational viscosity (RV), penetration aging index (PAI) and softening point index (SPI). The obtained results indicate that the utilization of modifiers helps in improving the physical properties of asphalt binders by different levels. the modification by collective modifiers leads to an increase SP, RV, PI, PAI, and SPI to 65%, 2 times, 1.044, 0.93, 2.5 respectively compared to neat bitumen. As well, leads to a decrease in both Pen. and ductility to the levels 45% and 79% respectively. This indicates that the use of waste and recycled modifiers especially in the combined form encourage the production of comparative modified asphalt binder.

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.

Predicted Affinity Ratio between Asphalt Binder and Aggregate

Affinity is a term used to describe the amount of the adhesion bond between asphalt binder and aggregate. Adhesion force may be used as indicator to the amount of energy or work required to breakdown the adhesive bond between asphalt binder and aggregate. In order to study affinity between asphalt binder and aggregate, a modified device is manufacture locally similar to Rolling Bottle Test (RBT) to Predicted the degree of affinity between asphalt binder and aggregate; taking into consideration mineral composition with physical properties of asphalt binder to measure required force to separate asphalt binder from aggregate surface. In this study, suggest new parameters to represent the stripping or affinity phenomena (affinity and stripping ratio) and the time required to make balance between them. From the experimental work result, the affinity ratio of aggregate brought from Dohuk region was 52 % after 24hr of rolling time period which is less than other type because of its mineral composition (high percent of calcite and dolomite which increase ability to resist stripping), pore size and stiffness of aggregate particle. In other hand, the stripping ratio of aggregate brought from al-Taji quarry was 80% after 24hr of rolling time which represent worse case in affinity of aggregate-asphalt binder system due to increased percent of quartz in mineral composition (greater than 80%) and so reduced ability of aggregate to resist stripping

Investigation on rheology and physical properties of asphalt binder blended with waste cooking oil

The service life of the concrete pavement is more than 20 years. While the service life of asphalt pavement is about ten years. The service life cannot be achieved due to pavement damage and increase the cost of road maintenance. The waste cooking oil gives a solution to soften the asphalt binder. The idea of using WCO is the possibility of transferring the aged asphalt binder condition from stiff to soft and reuse it for a new construction road. In this study, the bitumen grade 60/70 blended with 0, 2, 4, 6% of waste cooking oil by the weight of the bitumen. In this study, the bitumen prepared with various waste cooking oil percentage evaluated in terms of their properties such as the Softening point, Penetration, penetration index, penetration-viscosity number, Viscosity, and Dynamic Shear Rheometer. The test result indicates that the penetration values increased with rising the content of the waste cooking oil and the softening point result decreased related to the quantity of the waste cooking oil. The viscosity of the binder reduced when increased the content of WCO. The strength of the binder (G*) will decrease, and the elasticity of the binder (&) will grow when increased the content of the oil. The rutting parameter decreased with increased WCO. From this finding, it concluded that the waste cooking oil has a potential impact on soft the asphalt binder and can be used to produce a soft asphalt binder. Moreover, the 60/70 grade asphalt binder can be 80/100 after adding 2% of waste cooking oil.

Physico-chemo-rheological characterization of neat and polymer-modified asphalt binders

The physico-chemo-rheological properties of asphalt binder are critical for the long-term performance of asphalt pavement infrastructures. The objectives of this study are to characterize the physico-rheological properties of unmodified neat and polymer-modified asphalt binders with newly developed rheological performance tests, and further investigate the binder chemical properties as well as the possible performance relationship from macroscale to microscale perspective. Three neat asphalt binders and two styrene–butadiene–styrene (SBS) modified asphalt binders are selected in this study. The physical properties of asphalt binder include traditional penetration, softening point and ductility. The saturates, aromatics, resins and asphaltenes (SARA) fractionation test, gel permeation chromatography (GPC) and fourier transform infrared spectroscopy (FTIR) tests are respectively conducted to quantify the chemical composition, molecular weight distribution and structure properties of asphalt binders. The rheological rutting and fatigue resistance are evaluated through the multiple stress creep recovery (MSCR), linear amplitude sweep (LAS) and DSR-based elastic recovery (DSR-ER) tests. Experimental results indicate that the physical properties are only effective to distinguish the rheological performance of neat asphalt binders. The lower aromatics contents improve the binder rutting resistance and an unified relationship between aromatic contents and binder rutting performance is obtained for both neat and modified binders. In addition, increasing the amount of small asphalt molecules decrease the resistance to permanent deformation respectively for neat and modified binders. However, the small asphalt molecule is favorable for improving the binder fatigue performance. The large molecular size (LMS) parameter from GPC test is demonstrated a unified correlation to the fatigue life of both neat and modified binders.

Study on the effect of aging on physical properties of asphalt binder from a microscale perspective

The asphalt binder in pavement mixtures frequently exposed to oxygen and undergoes daily temperature cycles. This results in oxidation and dehydrogenation of its chemical composition, leading to the aging of the asphalt binder. The aging process of asphalt binder directly affects the pavement’s service life and therefore has been subject to intense research regarding the chemical composition and rheological properties. However, the microscopic reasons for these changes are not yet clear. A molecular dynamics (MD) simulation is employed to investigate the aging process from a microscale perspective. Six molecular models for six asphalt binders at different aging states are created based on the ratio of saturates, aromatics, resin and asphaltene (SARA) as well as carbonyl and sulfoxide indexes to investigate the effect of aging on physical properties of asphalt binder have been investigated. The results explain the mechanism for hardening of asphalt binder during aging process, and find some correlations between micro and macro phenomena.

Evaluation on High Temperature Rheological Properties of Nano-Montmorillonite Modified Asphalt Binder

Abstract The requirements for modified asphalt are increasing due to heavier load conditions and worse serving environments in modern highway construction. One of the methods for improving the properties of asphalt binder is to combine it with nano-montmorillonite (nano-MMT) because of the special nanolayer structure. This paper presents a study to evaluate physical and rheological properties of nano-MMT modified asphalt binders. The nano-MMT modified asphalt binder was prepared by melt blending different nano-MMT amounts. The physical properties of asphalt binder, including penetration, softening point, ductility, and viscosity, were tested. The dynamic shear rheometer (DSR) was carried out to evaluate high temperature rheological characteristics. Additionally, the high temperature storage stability was also discussed. Moreover, the effects of nano-MMT content on the abovementioned properties of nano-MMT–modified asphalt binder were investigated. Experimental results indicate that the penetration and ductility were decreased and the viscosity of the asphalt binder was increased by the addition of nano-MMT; however, the values enhancement represented more significantly when the content was up to 5 %. The modified asphalts especially exhibited higher complex moduli (G*), lower phase angles (δ), and higher rutting factors (G*/sin δ). These indicate that the addition of nano-MMT into the asphalt matrix can greatly improve the dynamic rheological and viscoelastic properties, which results in enhanced resistance to rutting at high temperatures. The storage stability tests disclosed that the asphalts modified with nano-MMT were very stable when nano-MMT content was less than 5 wt. %.

Influence of Aging on the Physical Properties and Chemical Compositions of Asphalt Binder with Soft Clay Particles

This study investigates the effect of oxidation aging on the physical properties of asphalt binder modified by various ratios of soft clay contents. The rheological properties of soft clay modified asphalt binders were performance under unaged and short-term aged, and being applied by using rotational viscometer and dynamic shear rheometer. Therefore, the results indicated that the physical properties of penetration and softening point were consistently reduced and increased, respectively for unaged and short-term aged specimens. The penetration index and viscosity aging index were increased as the soft clay modified binders aged and showed a high significance correlation. It also has the lowest susceptibility for the temperature susceptibility.

Multi-scale characterization of the effect of wax on intermolecular interactions in asphalt binder

This paper investigates the effect of paraffinic wax (commonly found in bio-oils produced from bio-mass) on the properties of asphalt binder as a commonly used additive in warm mix asphalt technologies. A comprehensive series of laboratory experiments combined with computational analysis was performed on an asphalt binder doped with four different percentages (1%, 3%, 5%, and 10%) of paraffin wax. Differential scanning calorimetry was used to study the effect of wax on physical properties of asphalt binder. Furthermore, rheological characteristics and fracture energy of each wax-doped specimen at sub-zero temperatures was measured to study the effect of wax crystallization on asphalt binder properties. To study intermolecular interactions, molecular dynamics simulation was performed on the wax-asphaltene assembly to study molecular conformation and packing of asphaltene molecules in the presence of wax. The results of molecular simulations provided insights into underlying intermolecular interactions that control rheological behavior. This was further reflected in a reduction of self-association of asphaltene molecules; as the wax concentration increased, the average size of asphaltene aggregates reduced. However, the number of clusters of asphaltene increased as wax concentration increased from 1% to 10% in asphaltene matrix. Accordingly, simulations results combined with laboratory characterization contributed to the understanding of the effects of different concentrations of paraffin wax on asphalt rheological properties.

Effects of Aging on the Low Temperature Properties of Asphalt Binder and its Mixture

Effect of aging on physical properties of asphalt binder was studied. The relationship between degradation of the low temperature properties of asphalt binder and asphalt mixture was also investigated. After the thin film oven test (TFOT) with different aging time, the AH-70 binder and the SBS modified asphalt binder were used to prepared asphalt mixture samples. The binder was characterized using penetration, ductility and Beam Bending Rheometer (BBR), and the low temperature cracking resistance of asphalt mixture was studied by Three-point Bending Fracture (TBF). The correlation between different physical parameters of binder, as well as between different aging properties of the binder and asphalt mixture, was examined. The results showed that aging influenced binder physics significantly, and resulted in a decline in the properties of low temperature cracking resistance of asphalt mixture. Although, aging susceptibility of binder and asphalt mixture may be ranked differently when different evaluation methods ware used, a strong correlation was observed between the aging of binder and asphalt mixture.

Effect of Crumb Rubber Modifiers (CRM) on Characteristics of Asphalt Binders in Sudan

The use of Crumb Rubber Modifiers (CRM) in flexible pavements to improve characteristics of asphalt binders has become a technique of great potential in recent years. In this regard an experimental program was undertaken to study the influence of CRM on the physical properties of asphalt binder. Asphalt cement modified with varying percentages of CRM, 0, 5, 10, 15, 20, and 30 percent were studied. Penetration, ductility, viscosity, softening point, flash and fire points, and specific gravity tests were performed on base and modified asphalts. The tests results show that addition of CRM to base asphalt has significant influence on its properties. Comparing the tests results, the viscosity, softening point, flash and fire points of the modified asphalts increased significantly, coupled with reduction in penetration and ductility as the CRM content increased. Addition of 15% CRM resulted in 200% and 15% increment in viscosity and softening point of base asphalt respectively, while the reduction in ductility and penetration were almost 75% and 25% respectively. It could be concluded that modification of asphalt binders by crumb rubber is successful and more beneficial technique.

Molecular dynamics study of interfacial mechanical behavior between asphalt binder and mineral aggregate

This study aims to study the deformation and failure behavior of the asphalt-aggregate interface using molecular dynamics (MD) simulations. The 12-component asphalt molecular models and the hydrated silica substrate were employed to form a bi-material interface system. Physical properties of asphalt binder were predicted from MD simulations including density and glass transition temperature for model validation with experimental data. Tensile simulations were performed and the stress-separation responses were obtained to analyze the interfacial mechanical behavior. It was found that the interface failure was mainly adhesive failure although large air voids were formed in the bulk asphalt as the loading rate decreases to a certain level. The interface failure strength and post-peak deformation are affected by loading rate and temperature that is consistent the viscoelastic behavior of asphalt binder. The stress-separation responses match the cohesive zone model (CZM) model that is usually observed in the pull-off strength test at the macroscopic scale. The relationship between chemical compositions of asphalt binder and the interface failure parameters was investigated. The MD simulation shows promising results to understand mechanical failure of asphalt-aggregate interface at the atomistic scale.