scholarly journals Investigation on Preparation Process and Storage Stability of Modified Asphalt Binder by Grafting Activated Crumb Rubber

Materials ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 2014 ◽  
Author(s):  
Juan Xie ◽  
Yueming Yang ◽  
Songtao Lv ◽  
Xinghai Peng ◽  
Yongning Zhang

According to the theory of molecular design, crumb rubber was grafting activated with acrylamide and then used as asphalt binder modifier. An orthogonal three-factor, three-level test was designed to optimize the preparation process of modified asphalt. Softening point, viscosity, rutting factor, ductility, stiffness modulus and creep speed index were selected as evaluation indicators to study the effects of rubber content, shear time and shear temperature by variance analysis and range analysis. The results show that the rubber content had a significant impact on the performance of modified asphalt with grafting-activated crumb rubber, while the shear temperature and shear time had little effect. The grafting activated crumb rubber content of 20%, shear temperature of 170–190 °C, and shear time of 90 min was determined as the reasonable preparation process. Modified asphalt with common crumb rubber (CRMA) and modified asphalt with grafting activated crumb rubber (A-G-R) were prepared, respectively, using the reasonable process to analyze the influence of grafting activation of crumb rubber. The results indicate that A-G-R had smaller softening point difference, lower segregation index and more stable and uniform dispersed phase.

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.


2016 ◽  
Vol 78 (7-3) ◽  
Author(s):  
Rosnawati Buhari ◽  
Nur Fareesya Zabidi ◽  
Mohd Ezree Abdullah ◽  
Siti Khatijah Abu Bakar ◽  
Nurul Hidayah Mohd Kamarudin

The objectives of this study were to determine the blending parameters of coconut shell powder (CSP) modified asphalt binder and to evaluate the rheological properties of CSP modified asphalt binder. CSP of 2%, 4%, 6%, 8% and 10% by weight of asphalt have been incorporated into an unaged 80/100 asphalt mix in order to improve its performance. The influence of the additives on the physical and rheological properties was evaluated with penetration test, softening point, storage stability, dynamic shear rheometer test (DSR), and Field Emission Scanning Electron Microscope (FESEM). The aging of asphalt binders was simulated in a laboratory by using Rotational Thin Film Oven (RTFO). The results showed that the addition of CSP into virgin binder was decreasing the penetration value and increasing the softening point temperature compared to the original binder. On the rheological effect, for unaged modified binder, higher CSP resulted higher G*/sin δ especially at lower temperature compared to the unaged control binder. Besides, for the aged modified binder, stiffness was lower than the control aged binder for all temperature.


2011 ◽  
Vol 71-78 ◽  
pp. 1062-1067 ◽  
Author(s):  
Zhen Gang Feng ◽  
Jian Ying Yu ◽  
Heng Long Zhang ◽  
Dong Liang Kuang

The modified asphalt binders with various anti-ageing additives, including ultraviolet (UV) absorber, antioxidant and combination of them, were prepared, and the effects of UV absorber contents, antioxidant contents and combination of UV absorber and antioxidant on physical properties and ageing characteristics of the asphalt binder were investigated. Results show that the ductility of asphalt binder increases whereas the softening point and viscosity decrease with addition of anti-ageing additives. UV absorbers and antioxidants exhibit different influences on the ageing properties of asphalt binder. The thermal- and photo-oxidative ageing performance of asphalt binder can be simultaneously improved by the compound modification with UV absorber and antioxidant. The combination of UV326 and antioxidant 1010 shows synergistic effect in preventing the asphalt binder from thermal- and photo-oxidative ageing, which contributes to excellent ageing resistance of modified asphalt binder.


Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3679
Author(s):  
Juan Xie ◽  
Yongning Zhang ◽  
Yueming Yang ◽  
Yunlong Ma ◽  
Jing Li ◽  
...  

Poor storage stability is a key problem restricting the rapid development and wide application of rubber-modified asphalt binder, and activation of rubber has shown good prospects to solve this problem. In this study, two activation methods, coating by polyamide 6 and grafting by acrylamide, were introduced to treat crumb rubber. Then the activated rubber was added to base asphalt binder to prepare modified asphalt binder. The chemical structure and morphology of rubber powder before and after activation and of asphalt binder before and after modification were characterized by Fourier transformation infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). The conventional and rheological properties and storage stability were analyzed to reveal the influence of activation method on the performance of asphalt binder. The results showed that after being activated, the surface of the rubber is loose and rough. A chemical reaction did not occur during activation by polyamide but occurred during activation by acrylamide. The activation of the rubber effectively improved the high- and low-temperature performance, and the softening difference decreased by 79.8%. This is because the interaction between rubber and asphalt binder was enhanced through activation of rubber, and grafting activation had better effect due to the chemical reaction between the basic amide groups of acrylamide and acid groups of asphalt binder.


Author(s):  
Saqib Gulzar ◽  
B. Shane Underwood

Agencies have been increasing their use of polymer modified asphalt binders in recent years to address performance issues and lengthen the useful life of their pavements. When deployed these materials likely experience strain levels exceeding their linear viscoelastic (LVE) limits. The same situation exists in non-polymer modified asphalt binders as well, but the effect may be more pronounced in polymer modified systems because of their bi-phasic nature. In this study, terminally blended crumb rubber (CR-TB) modified asphalt is studied to understand and quantify the nonlinear viscoelastic response under large strains. The CR-TB binders are extensively used in pavements subjected to high vehicular loads and extreme climatic conditions; thereby, their response under large strains becomes more critical. The current standard characterization techniques are based on LVE response using small amplitude oscillatory shear rheology only and do not consider the behavior of binders under large strains. In this study, large amplitude oscillatory shear (LAOS) rheology is used as a framework to more thoroughly investigate the complete response of the CR-TB modified asphalt binder under large strains at 30°C, 40°C, 50°C, and 60°C and at the frequencies of 0.5, 1, and 5 Hz. The LAOS response is analyzed using Fourier-transform rheology and the orthogonal stress decomposition method involving Chebyshev polynomial representation. It is found that nonlinearity manifests greatly in this study material as strain levels increase and frequencies decrease. The relative nonlinearity increases with increasing strain amplitude and is more significant towards lower end of the tested temperature range. The CR-TB binder shows strain-stiffening/softening and shear-thinning/thickening behavior depending upon a specific temperature, strain level, and frequency.


2015 ◽  
Vol 75 (11) ◽  
Author(s):  
Md. Maniruzzaman A. Aziz ◽  
Ahmed Wsoo Hamad ◽  
Abdulmalik Musa Maleka ◽  
Fauzan Mohd Jakarni

This paper dealt with the viscoelastic behavior of Cellulose Oil Palm Fiber (COPF) modified 60-70 penetration grade asphalt binder for the deterioration of roads. The main objective of this study was to investigate the effect of various COPF contents on the physical and the rheological properties of penetration grade 60-70 asphalt binder. Laboratory tests performed comprised of viscosity, penetration, softening point, short & long term ageing, as well as complex shear modulus (G*).  The COPF was blended in 0.2, 0.4, 0.6, 0.8, and 1.0% by weight of asphalt binder, including 0% as control. The COPF modified asphalt binder showed an increasing viscosity and softening point with the increase of COPF content, whereas the penetration decreased as the COPF was increased for the binder. The complex shear modulus (G*), rutting factor (G*/sin δ), and fatigue factor (G*sin δ) showed significant improvement for the modified samples compared to the unmodified samples. The results indicated that the COPF modified asphalt binder had high potential to resist permanent (rutting) deformation and fatigue cracking than the unmodified sample. 


2022 ◽  
Vol 331 ◽  
pp. 129978
Author(s):  
Jiuguang Geng ◽  
Mingyuan Chen ◽  
Caiyun Xia ◽  
Xiaofeng Liao ◽  
Zhongda Chen ◽  
...  

2019 ◽  
Vol 8 (1) ◽  
pp. 20190045 ◽  
Author(s):  
Dharamveer Singh ◽  
Vinamra Mishra ◽  
Shashi Bhushan Girimath ◽  
Aditya Kumar Das ◽  
Bharat Rajan

2021 ◽  
Vol 299 ◽  
pp. 124299
Author(s):  
Jiuguang Geng ◽  
Mingyuan Chen ◽  
Caiyun Xia ◽  
Xiaofeng Liao ◽  
Zhongda Chen ◽  
...  

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