Temperature Susceptibility Of Asphalt Binder Research Articles

Temperature susceptibility of asphalt binder modified with palm oil mill sludge

Modification of asphalt binder is continuously gaining interest as a result of the depletion of this non-renewable materials and their expensive price. There is a drive to use modifiers in asphalt including agricultural waste. In this study, palm oil mill sludge (POMS) was employed. The penetration grade of 60/70 as base binder incorporating with 1%,2%,3%,4% and 5% POMS were investigated for temperature susceptibility. These modified binders were tested for penetration, softening point, and viscosity. Subsequently, the penetration index (PI), penetration-viscosity number (PVN), activation energy (Ea) and viscosity-temperature susceptibility (VTS) were used to analyze the effect of POMS on the temperature susceptibility of asphalt binder. The results showed that the addition of POMS to the asphalt binder under unaged circumstances increased the penetration value from 66.56 dmm to 80.08 dmm and decreased the softening point from 49.25°C to 45.6°C for 4% POMS which indicates the softening effect of the asphalt binder. In contrast, following short-term ageing, the penetration value decreased as the softening point increased, showing that the modified asphalt binder stiffened after aging. According to the PI, PVN, Ea and VTS values of the modified POMS asphalt binder, the addition of POMS decreased its temperature susceptibility. Based on the ranking, 4% POMS was found as the best concentration of asphalt binder modifier. In conclusion, the use of appropriate amounts of POMS as an asphalt modifier is possible and provides a possible way to reuse POMS.

The Possibility to Reuse Nanocomposite Industrial Wastes for Asphalt Binder Modification Technology

A nanocomposite solid waste polymer has been used for increasing the durability of pavements that the softness of asphalt binder drops seriously at high temperature. The research is concerned with the possibility of utilizing locally available materials as an ingredient in asphalt concrete to enhance pavement performance, increase the mixture engineering property and at the same time decreasing the amount of bitumen required. The experimental work includes characterization of bitumen by using super pave tests (Dynamic Shear Rheometer) for both neat and modified bitumen. In this specific investigation the wet process is used for introducing the Portland cement, ceramic dust and Hydrate lime into bitumen during a modification process. Overall, 3 specimens with, 3 modifiers together with content 0 (neat bitumen), 1.5, 3.0 and 4.5 % by weight of asphalt binder were prepared. By considering the results generated from Dynamic Shear Rheometer (DSR); the isochronal plots indicates that a neat asphalt binder modified with composite of Portland cement, hydrate lime and ceramic dust resulting in the decreasing phase angle value and at the same time increasing the stiffness modulus of bitumen. This indicates that, on the 1 side, better stiffness and elastic behavior that the asphalt binder can directly suit for higher stability to resist rutting, hence, bitumen performance was upgraded with content of modifiers increased. On the other side, the heat insulation effect of the Portland cement, hydrate lime and ceramic dust will improves the temperature susceptibility of the asphalt binder which corresponds to permanent deformation resistance.
 HIGHLIGHTS
 
 One of the common problem is temperature susceptibility of asphalt binder resulting permanent deformation at hot climate area
 Portland cement, ceramic dust and hydrate lime modifiers mixed together with different contents into asphalt binder during a modification process in order to find out asphalt binder which corresponds to rutting resistance
 Increased stiffness modulus and decreased phase angle values has been achieved as a content of modifiers increased and the heat insulation effects of the modifiers will improves the temperature susceptibility of asphalt binder
 
 GRAPHICAL ABSTRACT

Rheological properties and aging performance of sulfur extended asphalt modified with recycled polyethylene waste

This study examines the effect of two different recycled plastic waste (RPW) which are high and low-density polyethylene (RHDPE and RLDPE) on the rheological/viscoelastic characteristics and aging performance of virgin asphalt and sulfur extended asphalt (SEA). Four dosages of the RPW additives representing 2%, 4%, 6%, and 8% by weight of the asphalt binder were investigated. The rheological characteristics of the RPW modified binders (virgin and SEA) are characterized at original and short-term aging conditions through the Rotational Viscometer (RV) and dynamic shear rheometer (DSR) tests. Fatigue performance is also characterized at the long-term aging condition. Also, high-temperature performance, dynamic storage stability (DSS), multiple stress creep and recovery (MSCR) are studied. Testing results show that RPWs lead to improved rutting and fatigue performance. Adding RPW to the virgin and SEA binders slows the binder oxidation reactions during the short-term aging. The Aging Index (AI) is found to be dependent on the asphalt rheological properties, amount/type of RPW, binder type, and temperature. RHDPE leads to an unstable modified virgin asphalt. Less than 4% RHDPE or 8% RLDPE with virgin asphalt show good DSS in terms of degradation and separation. The RPW with SEA meets the requirement of time degradation and separation set by the Federal Highway Administration (FHWA). The temperature susceptibility of asphalt binder decreases dramatically with the RPW modification making the asphalt binder more suitable for use at a wider range of temperatures.

Effect of Thermochromic Materials on the Properties of SBS-Modified Asphalt Mixture

Styrene-butadiene-styrene copolymers (SBS)–modified asphalt mixture is widely used in high grade roads because of its excellent comprehensive performance. However, the black characteristics and high temperature susceptibility of asphalt binder have a great impact on the performance of asphalt mixture. This paper mainly investigates the influence of different types of thermochromic materials on the properties of SBS-modified asphalt mixture, including high- and low-temperature performance, water stability, and the aging effect of the natural environment on asphalt mixture (natural aging). According to test results, thermochromic materials slightly reduce the high-temperature performance of SBS-modified asphalt mixture. All three kinds of thermochromic materials can improve the low-temperature crack resistance of SBS-modified asphalt mixture, among which red thermochromic material with 2% content (named as 2%RTP) is the best. In addition, thermochromic materials of different colors can improve the water stability of SBS-modified asphalt mixture, and black thermochromic material with 2% content (named as 2%BTP) exhibits the best effect on improving the water stability. All three thermochromic materials can improve the antinatural aging property of SBS-modified asphalt mixture.

Evaluation of the performance and temperature susceptibility of gilsonite- and SBS-modified asphalt binders

Abstract This study investigated the effect of gilsonite and Styrene-Butadiene-Styrene (SBS) as asphalt binder modifiers on the physical and rheological properties of asphalt binders. For this, binder tests such as penetration test, softening point, rotational viscosity (RV), Dynamic Shear Rheometer (DSR), and Bending Beam Rheometer (BBR) were conducted on the neat and modified binders. The effect of gilsonite and SBS on the binder temperature susceptibility was also investigated by measuring Penetration Index (PI), Activation Energy (AE) and Viscosity-Temperature Susceptibility (VTS) of all the study binders. Fourier-Transform Infrared Spectroscopy (FTIR) test was directed toward investigation of the compositions’ structure. The statistical analysis was also utilized to investigate the effect of gilsonite and SBS on the physical and rheological properties and temperature susceptibility of asphalt binders. The results indicated that incorporation of gilsonite and SBS to asphalt binder decreases the temperature susceptibility and improves mechanical and rheological properties of the asphalt binders. In addition, the results showed significant relationships between PI, AE and VTS with high temperature performance grade (HT) for almost all the modified binders. Results of Analysis of Variance (ANOVA) revealed that even though the binder modifier type has no significant effects on PI, AE, VTS, and viscosity, the modifier dosage can significantly affect these parameters.

Performance evaluation of bio-based asphalt and asphalt mixture and effects of physical and chemical modification

Adding bio-binder (BB) into petroleum-based asphalt (BA) to produce the sustainable pavement material of bio-based asphalt (BBA), and replace the BA partially or even fully could reduce the dependence of pavement engineering on fossil fuels. This study aims to investigate the effects of adding single-source BB from corn on asphalt binder and asphalt mixture performance. Rheological properties measured from Rotational Viscometer (RV), Dynamic Shear Rheometer (DSR) and Bending Beam Rheometer (BBR) showed that addition of BB increased the viscosity while decreased the temperature susceptibility of asphalt binder, the BBA became stiffer at high temperatures and more brittle at low temperatures. Pavement performance tests conducted at mixture level showed that adding BB is capable of improving rutting resistance while sacrificing low-temperature cracking resistance slightly, but moisture damage resistance decreased evidently. Therefore, chemical characterisation of BB and BA was conducted using Elemental Analysis, Gas Chromatography-Mass Spectroscopy (GC-MS), Fourier-Transform Infrared Spectroscopy (FTIR) and Saturates, Aromatics, Resins and Asphaltenes (SARA) Fractions Analysis was employed to investigate the performance variation mechanism due to the addition of BB. The results proved that a certain number of light and soluble components existed in BB. After that, physical and chemical modifications with the modifiers of Styrene–Butadiene–Styrene (SBS) block copolymer and o-Phthalic anhydride, respectively, were adopted to improve the performance of BBA. Mixture performance tests showed that physical method improved high- and low-temperature performance obviously while had no effect on moisture damage resistance. On the other hand, the chemical approach enhanced moisture damage resistance of mixture visibly while not affecting other performance criteria. The study findings emphasised that utilising BBA proposed to partially replace BA is potential and feasible with appropriate modification.

Comprehensive Evaluation of Temperature Sensitivity of WMA Binder with Sasobit

Two matrix asphalt binders were selected and mixed with Sasobit in different proportion to prepare warm mix asphalt binders (WMA), and the softening point, penetration and ductility at different temperatures were measured to analyze the temperature sensitivity of Sasobit WMA. Test results indicate that with the increase of Sasobit dosages, the penetration of asphalt binder decreases, and the decreasing amplitude of penetration at higher temperature is bigger. The softening point and equivalent softening point also increase, but the ductility decreases. The temperature induction coefficient decreases, penetration index increases, and the plastic range becomes larger with the increase of Sasobit dosages, meaning the temperature sensitivity is improved. The penetration index (PI), penetration-viscosity number (PVN) and viscosity-temperature susceptibility (VTS) were analyzed, and it can be founded that the temperature susceptibility of Sasobit WMA is improved at the service stage while the temperature susceptibility of asphalt binder at high temperature turns to be more sensitive.

Thermorheological Properties Of Styrene-Butadiene-Styrene (SBS) Copolymer Modified Road Bitumen

Abstract The purpose of the research work was to assess the rheological properties of SBS copolymer modified bitumens (PMB), which are mainly used in hot mix asphalt laid in the top layers of road and airfield pavements. Modified bitumens containing 0-9% of SBS copolymer were the objects of the tests. They were obtained by mixing highly modified bitumen containing 9% of SBS copolymer with Venezuelan and Russian road bitumens. The analysis includes the effect of temperature on the properties of the modified asphalt binders investigated in the range from -40°C to +80°C. Tests of modified bitumen samples were performed using dynamic shear rheometer (DSR) with oscillatory torsional kinematic force. The use of oscillatory force allowed to determine the rheological parameters of the tested binders, i.e. the complex shear modulus G⁎, the phase angle δ as well as the real (elastic) and imaginary (viscous) parts of the complex shear modulus. On the basis of the results of the study, rheograms showing a significant variation in the rheological properties of the tested binders were prepared. The following relationships were taken into account: shear modulus and damping factor vs. temperature, shear modulus vs. phase angle (Black diagram) as well as the relationship between loss and storage moduli (Cole-Cole diagram). In order to compare the influence of temperature on the stiffness of the tested binders, the SMI (Shear Modulus Index) was calculated using the Walther equation, covering a wide range of pavement operation temperatures (from -30°C to +60°C). Analysis of the SMI values showed a significant effect of the SBS copolymer content on reducing the temperature susceptibility of asphalt binders.

Investigating Effects of Application of Silica Fume to Reduce Asphalt Oxidative Aging

This paper investigates the feasibility of using silica fume to enhance the rheological properties of asphalt binder. It has been widely reported that asphalt binder oxidation is one of the phenomena that reduces the service life of asphalt pavement by negatively impacting its rheological properties. This in turn can lead to a more brittle pavement which is more prone to cracks due to thermal stress and traffic loading. Prior research has shown that introduction of nano-silica to asphalt can reduce asphalt oxidation aging; however, the main challenge with use of nano-silica found to be agglomeration of nano-particles to form micro size clusters which can reduce nano-silica effectiveness while making asphalt binder more susceptible to shear. Therefore, this paper studies effectiveness of using silica fume to reduce asphalt oxidative aging while alleviating agglomeration issue. To do so, various percentages of silica fume was introduced to a base asphalt binders and the rheological properties and high temperature performance of each specimen was evaluated by measuring the rotational viscosity and complex shear modulus before and after oxidative aging. Analysis of the experimental results showed that silica fume reduced asphalt aging index significantly; in addition the temperature susceptibility of asphalt binder was reduced as the percentage of silica fume increased. The flow of modified mixtures increased and the loss of stability of samples decreased as the amount of silica fume increased. The positive effect of silica fume on base asphalt’s rheological properties could be attributed to the high surface area and the low degree of agglomeration of the silica fume due to their high polarity. This in turn could improve silica fume’s blending properties resulting in a uniformly distributed silica fume modified matrix with enhanced oxidative aging resistance.

Rheological properties of amorphous poly alpha olefin (APAO) modified asphalt binders

The rheological properties of amorphous poly alpha olefin (APAO) modified asphalt binders were investigated through rotational viscometer (RV), dynamic shear rheometer (DSR), and bending beam rheometer (BBR) tests in the laboratory. Two types of APAOs and four percentages of APAO were selected in the study. RV results indicate that the addition of APAO increases the viscosity of modified asphalt binder at high temperatures. DSR measurements show that the elastic property of asphalt binder is enhanced and the failure temperature is improved due to the addition of APAO. In addition, BBR results demonstrate that additional APAO has negative effects on the creep stiffness and creep rate of the modified asphalt binders. The temperature susceptibility of asphalt binder is reduced at high, intermediate, and low temperature zones after adding APAO. Moreover, this study found that APAO K3050 has better modification than K3020 due to its higher viscosity.

Influence of conductive additive on temperature susceptibility of asphalt binders

The effects of graphite on temperature susceptibility of asphalt binders were investigated by penetration test, Ring & Ball softening point test and viscosity test. And penetration index (IP), viscosity-temperature susceptibility (SVT), and penetration-viscosity numbers (NPV) were introduced to evaluate the effects. The results show that the penetration, softening point and viscosity of asphalt binder increase with the increase of content of graphite. This means that the addition of graphite makes asphalts stiffer. The results from IP, NPV and SVT show that temperature susceptibility is reduced by the addition of graphite.

Fracture toughness of polymer-modified asphalt concrete at low temperatures

The fracture toughness of asphalt concrete increases at low temperature and then decreases at temperatures below a certain level. Some polymers are known to have the property of improving the temperature susceptibility of asphalt binder at low temperatures. Therefore, this study evaluated the fracture toughness (KIC) of some polymer-modified asphalt concretes. Low-density polyethylene (LDPE), styrene–butadiene–styrene (SBS), and a mixed polymer of LDPE and SBS were used in this study. The fracture toughness KIC of normal asphalt concrete was compared with that of polymer-modified asphalt (PMA) concrete, and the effectiveness of polymer modification against falling values of KIC was evaluated at low temperatures. The results showed that PMA concretes, in general, showed better KIC than normal asphalt concretes, and the temperature at which the highest KIC was obtained was lower than that in the case of normal asphalt concrete. Therefore, the PMA concretes evaluated in this study had better fracture resistance than normal asphalt at low temperatures.Key words: asphalt concrete, polymer-modified asphalt, PMA, fracture toughness, differential thermal contraction, low-temperature damage.