Aging characteristics of crumb rubber modified asphalt binder and mixture with regenerating agent

2021 ◽  
Vol 299 ◽  
pp. 124299
Author(s):  
Jiuguang Geng ◽  
Mingyuan Chen ◽  
Caiyun Xia ◽  
Xiaofeng Liao ◽  
Zhongda Chen ◽  
...  
Keyword(s):  
Asphalt Binder ◽  
Crumb Rubber ◽  
Modified Asphalt ◽  
Modified Asphalt Binder

scholarly journals The Effect of Activation Method of Rubber on the Performance of Modified Asphalt Binder

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3679
Author(s):  
Juan Xie ◽  
Yongning Zhang ◽  
Yueming Yang ◽  
Yunlong Ma ◽  
Jing Li ◽  
...  
Keyword(s):  
Chemical Reaction ◽  
Storage Stability ◽  
Rapid Development ◽  
Asphalt Binder ◽  
Polyamide 6 ◽  
Crumb Rubber ◽  
Activation Method ◽  
Modified Asphalt ◽  
Before And After ◽  
Modified Asphalt Binder

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.

Nonlinear Viscoelastic Response of Crumb Rubber Modified Asphalt Binder Under Large Strains

2020 ◽  
Vol 2674 (3) ◽  
pp. 139-149
Author(s):  
Saqib Gulzar ◽  
B. Shane Underwood
Keyword(s):  
Asphalt Binder ◽  
Crumb Rubber ◽  
Oscillatory Shear ◽  
Asphalt Binders ◽  
Large Strains ◽  
Viscoelastic Response ◽  
Modified Asphalt ◽  
Nonlinear Viscoelastic ◽  
Modified Asphalt Binder ◽  
Polymer Modified Asphalt

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.

Evaluation of Rheological and Moisture Damage Properties of Crumb Rubber–Modified Asphalt Binder

2019 ◽  
Vol 8 (1) ◽  
pp. 20190045 ◽  
Author(s):  
Dharamveer Singh ◽  
Vinamra Mishra ◽  
Shashi Bhushan Girimath ◽  
Aditya Kumar Das ◽  
Bharat Rajan
Keyword(s):  
Asphalt Binder ◽  
Moisture Damage ◽  
Crumb Rubber ◽  
Modified Asphalt ◽  
Modified Asphalt Binder

Preparation Technology and Performance Analysis of Crumb Rubber and SBS Composite Modified Asphalt Binder

2010 ◽  
Vol 160-162 ◽  
pp. 1320-1324 ◽  
Author(s):  
Li Xiang ◽  
Zhi Gang Wang ◽  
Ying Du ◽  
Jian Cheng ◽  
Guo He Que
Keyword(s):  
Asphalt Binder ◽  
Crumb Rubber ◽  
Performance Comparison ◽  
Preparation Technology ◽  
Modified Asphalt ◽  
Comparison Results ◽  
Modified Asphalt Binder ◽  
Process Factors ◽  
And Performance ◽  
Separation Behavior

Based on the characteristics of SBS modified asphalt (SBSMA) and crumb rubber modified asphalt (CRMA), crumb rubber and SBS composites modified asphalt (CR/SBSCMA) technology is proposed combine the advantages of crumb rubber and SBS. The preparation technology and production process factors have been discussed in this work. Moreover, the performance comparison results of three modified asphalts confirms that CR/SBSCMA could achieve good high and low temperature performance with low content of SBS and crumb rubber. Furthermore, the separation behavior of CR/SBSCMA has been analyzed, the experimental results indicate that the separation behavior of CR/SBSCMA is caused by the sinkage of rubber particles as well as CRMA. However, the softening point difference of CR/SBSCMA after separation test is smaller greatly than CRMA due to the prevention of SBS particles.

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
Keyword(s):  
Softening Point ◽  
Molecular Design ◽  
Asphalt Binder ◽  
Crumb Rubber ◽  
Preparation Process ◽  
Range Analysis ◽  
Rubber Content ◽  
Segregation Index ◽  
Modified Asphalt ◽  
Modified Asphalt Binder

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.

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