The Influence of Crumb Rubber on Modified Bitumen Properties

Author(s):  
Ovidijus Šernas ◽  
Donatas Čygas ◽  
Audrius Vaitkus ◽  
Vytautė Gumauskaitė

Rubber derived from grinding of recycled cars and trucks tyres may be successfully used as a bitumen modifier. Number of researches reported sufficient characteristics of rubber modified asphalt binders or modified asphalt mixes in terms of improved permanent deformation and fatigue cracking. The behavior of crumb rubber asphalt binders depends on several factors, such as modification method, rubber content and size, modification temperature, mixing speed and time applied during the digestion process. The aim of this study is to evaluate the effect of crumb rubber amount and type on modified bitumen low and high temperature properties. This paper presents results of unmodified bitumen, crumb rubber crumb rubber and polymer modified bitumen. Low and high temperature properties have been evaluated using bending beam rheometer and dynamic shear rheometer. Moreover, softening point and viscosity tests have been performed. The study results revealed that crumb rubber modified bitumen performed better than pure bitumen and similarly to polymer modified bitumen.

2019 ◽  
Vol 9 (8) ◽  
pp. 1567 ◽  
Author(s):  
Huang Xiaoming ◽  
Ismail Bakheit Eldouma

The overall objectives of this study were to determine the most appropriate additive for improving the physical properties and the medium- and high-temperature performances (mechanical performance) of asphalt binders. Three different types of modified binders were prepared: crumb rubber modifier (CRM), polypropylene (PP), and tafpack super (TPS), which had concentrations of 2%, 3%, 3.5%, and 4% by weight of asphalt binder, for each modifier. Their physical and rheological properties were evaluated by applying various tests such as ductility, rotational viscosity, toughness, and tenacity, as well as the dynamic shear rheometer (DSR) test. As a result, the physical properties of the modified bitumen binders were compared, as were the medium- and high-temperature performances (mechanical performance), which had temperatures of 58, 64, 70, 76, 82, and 88 °C, respectively. This was how the most appropriate modifier was determined. The results demonstrated that the asphalt binder properties significantly improved by utilizing CRM followed by PP and TPS modifiers. The increase in the rutting parameter (G*/sin(δ)) after asphalt modification indicated its excellent performance at both medium- and high-temperatures. Lastly, the CRM was determined as the most preferred additive because of its positive effect on the physical properties and enhancement of the medium- and high-temperature performance (mechanical performance).


2011 ◽  
Vol 255-260 ◽  
pp. 3195-3199
Author(s):  
Lan Wang ◽  
Yong Ming Xing ◽  
Chun Qing Chang

Compound crumb rubber modified asphalt (CCRMA) is a kind of compound modified asphalt. It is made from putting granulated crumb rubber (GCR) crashed from scrap tires and SBS modifier into matrix asphalt, though shearing by high speed shearing machine and growthing. It has good low temperature crack-resistant attributes, and better preventing high temperature distortion as well. The application of abandoned rubber tire is significant to cutting down on pollution,developing circular economy and protecting the environment. The microstructure of matrix asphalt and CCRMA is observed by SEM. Based on the results of temperature sweep test for CCRMA and uniaxial compression creep test for CCRMA mixture, the high-temperature characteristic of compound modified asphalt and mixture is studied. It is observed that, CCRMA has preferable anti-permanent deformation performance. CCRMA mixture has perferable anti-high temperature deformation performation. In the meantime, the viscous-elastic parameters of CCRMA mixture is obtained by fitting experimental data, it provides a referance for viscoelastic mechanics analyze of bituminous pavement.


2021 ◽  
Vol 13 (18) ◽  
pp. 10271
Author(s):  
Yuchen Guo ◽  
Xuancang Wang ◽  
Guanyu Ji ◽  
Yi Zhang ◽  
Hao Su ◽  
...  

The deteriorating ecological environment and the concept of sustainable development have highlighted the importance of waste reuse. This article investigates the performance changes resulting from the incorporation of shellac into asphalt binders. Seashell powder-modified asphalt was prepared with 5%, 10%, and 15% admixture using the high-speed shear method. The microstructure of the seashell powder was observed by scanning electron microscope test (SEM); the physical-phase analysis of the seashell powder was carried out using an X-ray diffraction (XRD) test; the surface characteristics and pore structure of shellac were analyzed by the specific surface area Brunauer-Emmett-Teller (BET) test; and Fourier infrared spectroscopy (FTIR) qualitatively analyzed the composition and changes of functional groups of seashell powder-modified asphalt. The conventional performance index of seashell powder asphalt was analyzed by penetration, softening point, and ductility (5 °C) tests; the effect of seashell powder on asphalt binder was studied using a dynamic shear rheometer (DSR) and bending beam rheometer (BBR) at high and low temperatures, respectively. The results indicate the following: seashell powder is a coarse, porous, and angular CaCO3 bio-material; seashell powder and the asphalt binder represent a stable physical mixture of modified properties; seashell powder improves the consistency, hardness, and high-temperature performance of the asphalt binder but weakens the low-temperature performance of it; seashell powder enhances the elasticity, recovery performance, and permanent deformation resistance of asphalt binders and improves high-temperature rheological properties; finally, seashell powder has a minimal effect on the crack resistance of asphalt binders at very low temperatures. In summary, the use of waste seashells for recycling as bio-modifiers for asphalt binders is a practical approach.


2019 ◽  
Vol 8 (4) ◽  
pp. 5501-5508

The crumb rubber modifier (CRM) particles release polymeric fractions in the matrix of the asphalt binder, which increase the asphalt binder’s fatigue and rutting resistance. The used motor oil (UMO) compensates the asphalt binder for the low-molecular-weight components lost during the aging processes. Moreover, UMO could increase the asphalt binder’s fluidity and softness. Therefore, modification of the asphalt binder by CRM in combination with UMO could enhance the asphalt binder’s performance. In this paper, the asphalt binder was modified by CRM. Then, the UMO was added to the crumb rubber modified asphalt (CRMA). The neat asphalt, CRMA, and UMO–CRMA binders’ resistance to rutting and fatigue cracking was evaluated. Temperature sweep test was used to evaluate the neat and modified asphalt binders’ resistance to rutting and fatigue cracking by measuring |G*|/sinδ and |G*|.sinδ parameters, respectively. Linear amplitude sweep (LAS) test was used to analyze the neat and modified asphalt binders’ resistance to fatigue cracking by measuring the number of load repetitions to failure (Nf ). It was found that using CRM and UMO enhanced the asphalt binder’s resistance to rutting and fatigue cracking. Therefore, UMO succeeded as a rejuvenator to balance the CRMA binder’s performance. This had occurred by creating a balance between the enhanced properties at high, intermediate, and low temperatures. Interaction temperature plays a dominant role in enhancing the asphalt binder’s performance: the enhancement in rutting and fatigue cracking parameters reached the highest values for CRMA or UMO–CRMA samples interacted at 190°C interaction temperature. At 220°C interaction temperature, these enhancements had decreased due to the devulcanization and depolymerization processes of the polymeric components released in the asphalt binder’s matrix.


2020 ◽  
Vol 6 (5) ◽  
pp. 1017-1030
Author(s):  
Maria Iqbal ◽  
Arshad Hussain ◽  
Afaq Khattak ◽  
Kamran Ahmad

With the increase in demand of flexible pavements, due to their various advantages over rigid pavements, there is a need to improve the aging properties of the bitumen in order to enhance its resistance against different types of distresses such as rutting, fatigue cracking. This research focus on the use of one polymeric additive Polyethylene (PE) and one non polymeric additive Sulphur (S) to enhance the aging resistance of asphalt. These modifiers are evaluated for their effect on the aging mechanism in comparison with the unmodified bitumen. Aging of the original and modified bitumen is realized by the Rolling Thin Film Oven (RTFO) and Pressure Aging Vessel (PAV). Physical properties of the aged and unaged asphalt binders are evaluated through empirical testing like penetration, ductility and softening point test. Optimum content of the modifiers is obtained by comparing the results of conventional properties before and after aging. Fourier Transformed Infrared Spectroscopy (FTIR) and Scanning Electron Microscope (SEM) are performed to bring out the chemical and morphological changes in the modified binder. Rheological properties of modified asphalt are evaluated with the help of a Dynamic Shear Rheometer (DSR). Results indicate improvement in physical properties of the modified asphalt even after the aging. Penetration index increased which shows less temperature susceptibility of the modified binders. Carbonyl and sulfoxide index are used as aging indicators which shows reduction in case of modified samples. Decrease in the sulfoxide and carbonyl index indicates better oxidation resistance of the modified samples. Morphological analysis proves good compatibility of the modifiers with asphalt binders. DSR results indicate improved viscoelastic properties of the modified binders. Hence it can be concluded that Polyethylene and Sulphur are good options to improve the aging resistance of asphalt in terms of their cost effectiveness and environment friendly nature.


2016 ◽  
Vol 112 ◽  
pp. 49-58 ◽  
Author(s):  
Ouming Xu ◽  
Feipeng Xiao ◽  
Sen Han ◽  
Serji N. Amirkhanian ◽  
Zhenjun Wang

Environments ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 47
Author(s):  
Lim Min Khiong ◽  
Md. Safiuddin ◽  
Mohammad Abdul Mannan ◽  
Resdiansyah

This paper presents the results of a laboratory-based experimental investigation on the properties of asphalt binder and hot-mix asphalt (HMA) mixes modified by locally available crumb rubber, which was used as a partial replacement of asphalt by weight. In this study, fine crumb rubber with a particle size in the range of 0.3–0.6 mm, obtained from scrap tires, was added to the asphalt binder through the wet process. Crumb rubber contents of 5%, 10%, 15%, and 19% by weight of asphalt were added to the virgin binder in order to prepare the modified asphalt binder samples, while the unmodified asphalt binder was used as the control sample. The crumb rubber modified binder samples were examined for measuring viscosity indirectly using the penetration test, and temperature resistance using the softening point test. Later, both the modified and unmodified asphalt binders were used to produce HMA mixes. Two categories of HMA mix commonly used in Malaysia—namely, AC 14 (dense-graded) and SMA 14 (gap-graded)—were produced using the modified asphalt binders containing 5%, 10%, 15%, and 19% crumb rubber. Two AC 14 and SMA 14 control mixes were also produced, incorporating the unmodified asphalt binder (0% crumb rubber). All of the AC 14 and SMA 14 asphalt mixes were examined in order to determine their volumetric properties, such as bulk density, voids in total mix (VTM), voids in mineral aggregate (VMA), and voids filled with asphalt (VFA). In addition, the Marshall stability, Marshall flow, and stiffness of all of the AC 14 and SMA 14 mixes were determined. Test results indicated that the modified asphalt binders possessed higher viscosity and temperature resistance than the unmodified asphalt binder. The viscosity and temperature resistance of the asphalt binders increased with the increase in their crumb rubber content. The increased crumb rubber content also led to improvements in the volumetric properties (bulk density, VTM, VMA, and VFA) of the AC 14 and SMA 14 mixes. In addition, the performance characteristics of the AC 14 and SMA 14 mixes—such as Marshall stability, Marshall flow, and stiffness—increased with the increase in crumb rubber content. However, the AC 14 mixes performed much better than the SMA 14 mixes. The overall research findings suggest that crumb rubber can be used to produce durable and sustainable HMA mixes, with manifold environmental benefits, for use in flexible pavements carrying the heavy traffic load of highways.


Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1200 ◽  
Author(s):  
Cheng ◽  
Liu ◽  
Ren ◽  
Huang

Crumb rubber, as a recycled material used in asphalt mixture, has gained more attention in recent years due to environmental benefits and the advantages of its pavement, such as excellent resistance to cracking, improved durability, less road maintenance, lower road noise, etc. However, the high-temperature performance of mixture with crumb rubber does not perform well. In order to improve the performance, this paper examined the effect of additives on the laboratory performance of asphalt rubber Stone Matrix Asphalt (AR-SMA) with additives. Three groups of AR-SMA: no additives, Styrene–Butadiene–Styrene (SBS) and Granular Polymer Durable additive (GPDa) were included, with no additives as a control group. Each group was investigated at three asphalt rubber content (ARC): 6.4%, 6.9%, 7.4% with regard to high-temperature and fatigue properties. The results show that with increasing ARC, the high-temperature performance of mixture without additive decreases, and the high-temperature performance increases first and then decreases for SBS and GPDa. Moreover, the rutting resistance of AR-SMA with GPDa at 6.9% ARC performs best. Under the condition of mixtures with appropriate ARC, AR-SMA with GPDa has higher fatigue life and sensitivity to fatigue cracking than the control group. Simultaneously, the fatigue performance of AR-SMA with GPDa is not as significant as that without additive with increasing ARC. In a word, GPDa is a good choice to improve the performance of AR-SMA. However, it should be noted that optimal asphalt content of AR-SMA mixtures with GPDa is higher than that of traditional mixtures.


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