Microstructure and Temperature Characterization of Compound Crumb Rubber Modified Asphalt

2014 ◽  
Vol 1052 ◽  
pp. 382-386 ◽  
Author(s):  
Lan Wang ◽  
Jiang San Hu ◽  
Gang Chen
Keyword(s):  
Complex Modulus ◽  
Crumb Rubber ◽  
Dynamic Shear ◽  
Rotational Viscometer ◽  
Rubber Powder ◽  
Modified Asphalt ◽  
Rubber Particles ◽  
Powder Content ◽  
Rotary Viscometer

Compound Crumb Rubber Modified Asphalt (CCRMA) is a mixture of waste rubber tire powder, SBS modifier and asphalt in order to modify the characteristics of asphalt. The application of using crumb rubber powder in making CCRMA is important in improvement of working characteristics of asphalt as well as in pollution control and environment protection. CCRMA, crumb rubber particles, SBS modifier and base asphalt have been examined by Scanning Electron Microscope (SEM) to observe the microcosmic appearance and the characteristic distribution of crumb rubber particles and SBS modifier in asphalt. The rotary viscometer test and dynamic shear test of CCRMA were carried out by rotational viscometer and Dynamic Shear Rheology (DSR). The influences of rubber powder content and reaction time to viscosity of CCRMA have been studied. In the stage of current study, complex modulus and phase angle of CCRMA are parameters reflecting viscoelasticity, the relation between them and temperature are researched.

scholarly journals Swelling and Degradation Characteristics of Crumb Rubber Modified Asphalt during Processing

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Caiyun Xia ◽  
Mingyuan Chen ◽  
Jiuguang Geng ◽  
Xiaofeng Liao ◽  
Zhongda Chen
Keyword(s):  
Crumb Rubber ◽  
Continuous Phase ◽  
Expansion Ratio ◽  
Processing Technology ◽  
Processing Temperature ◽  
Rubber Powder ◽  
Modified Asphalt ◽  
Relationship Model ◽  
Long Time ◽  
Asphalt Performance

The existence of cross-linked structure in crumb rubber modified asphalt (CRMA) leads to the complexity of its system. According to the preparation test of CRMA under different processing technology, the influence of processing temperature and time on the properties and cross-linking structure of CRMA was analyzed. By analyzing the volume expansion rate of the rubber powder after swelling and the toluene insoluble content attenuation rate, the formation conditions of the macro-level cross-linked structure were determined, and the relationship model between the cross-linked structure and the rubber asphalt performance was established. The results show that the rubber particles can form a continuous phase structure after swelling. At this time, the expansion ratio of the swollen rubber powder was 1.76–2.14. Too high temperature (above 200°C) and too long time (above 60 min) caused serious degradation of rubber. The suitable processing technology was stirring at 180–190°C for 45–60 min.

scholarly journals Evaluation of Petroleum Resin in Rubberized Asphalt Binder

2021 ◽  
Vol 13 (16) ◽  
pp. 9319
Author(s):  
Hyun Hwan Kim ◽  
Mithil Mazumder ◽  
Moon-Sup Lee ◽  
Soon-Jae Lee
Keyword(s):  
Thin Film ◽  
Low Temperatures ◽  
Asphalt Binder ◽  
Crumb Rubber ◽  
Creep Recovery ◽  
Dynamic Shear ◽  
Bending Beam Rheometer ◽  
Rotational Viscometer ◽  
Multiple Stress ◽  
Multiple Stress Creep Recovery

The crumb rubber modified (CRM) binder was evaluated considering the general operating temperatures of high, intermediate, and low temperatures. CRM binders were produced with four different contents (0, 5, 10, and 15%) using the base asphalt binder (PG64-22). Then, they were artificially aged by a rolling thin-film oven (RTFO) and pressure aging vessel (PAV). Superpave binder tests using a rotational viscometer (RV), dynamic shear rheometer (DSR), and bending beam rheometer (BBR) was applied to characterize the performance of the original and aged binders. Multiple stress creep recovery (MSCR) tests were also performed for deeper rutting characterization. The results of this study are as follows: (1) the presence of PR increases the binder viscosity, (2) the integration of CRM greatly improved the rutting resistance of the binder, and it was found that PR also improved the rutting characteristics, and (3) it is observed that PR is detrimental to the cracking properties of CRM binders.

scholarly journals Stability Evaluation and Mechanism of Asphalts Modified With Various Rubber Powder Contents

2021 ◽  
Vol 7 ◽  
Author(s):  
Hengxiao Xue ◽  
Yuanbo Cao ◽  
Qi Liu ◽  
Hongfei Zhang ◽  
Mingliang Zhang
Keyword(s):  
Low Temperature ◽  
Softening Point ◽  
Stability Index ◽  
Test Methods ◽  
Segregation Index ◽  
Rubber Powder ◽  
Evaluation Indexes ◽  
Modified Asphalt ◽  
Powder Content ◽  
Storage Properties

Ground tires are one of the main sources of urban solid waste. Rubber powder-modified asphalt provides an effective method to solve the problem, and it presents good high- and low-temperature performance in sustainable pavement construction. However, the storage properties of rubber powder-modified asphalts prepared from the traditional low-temperature shear mixing method are unstable, which restricts their application. In this study, four test methods (the softening-point test; the dynamic shear rheological test; the Laboratory Asphalt Stability Test; and fluorescence image analysis) and six evaluation indexes (the softening-point difference Sdiff, the segregation percentage Sp, the segregation index Ise, the segregation rate Rs, the degradation rate Rd, and the stability index Ist) were employed to analyze the storage abilities of asphalts modified by various activated rubber powder contents. The results show that the storage properties have a positive correlation with rubber powder content in the modified asphalt, and a rubber powder content of 60% is proven to be the optimum mixing amount. The rubber powders can distribute uniformly in the asphalt matrix when mixed below the optimum mixing amount; otherwise a rubber powder agglomeration is formed. The quantitative morphology analysis results are in good agreement with the laboratory test conclusions. The activated rubber powder shows better compatibility compared with ordinary rubber powders and presents a promising method to treat waste ground tires.

scholarly journals Investigation on Rheological Properties and Storage Stability of Modified Asphalt Based on the Grafting Activation of Crumb Rubber

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1563 ◽  
Author(s):  
Xie ◽  
Yang ◽  
Lv ◽  
Zhang ◽  
Zhu ◽  
...  
Keyword(s):  
Rheological Properties ◽  
Storage Stability ◽  
Crumb Rubber ◽  
Modified Asphalt ◽  
Rubber Particles ◽  
Polymer Separation ◽  
Low Temperature Creep ◽  
Rheological Test ◽  
And Storage ◽  
Separation Test

Acrylamide with a double bond and amide group can not only copolymerize with macromolecules of crumb rubber but also react with acidic groups in asphalt, so it was selected as a modifier to activate crumb rubber through chemical graft action. The purpose is to improve the compatibility between crumb rubber and asphalt and thus improve the rheological properties and storage stability of rubber asphalt. Infrared spectroscopy (IR) and scanning electron microscopy (SEM) were used to characterize the crumb rubbers and their modified asphalt. It was found that the crumb rubber of grafting acrylamide had better compatibility in asphalt due to its larger specific surface area and chemical reaction with asphalt. In addition, the high temperature rheological test, low temperature creep test, and polymer separation test were carried out to study the effect of grafted activated crumb rubber on the properties of modified asphalt. The results showed that compared with modified asphalt with common crumb rubber (CRMA), the rheological properties and storage stability of modified asphalt with grafting activated crumb rubber (A–G–R) were improved significantly. The results of microscopic and macroscopic tests show that the activated rubber particles have a larger contact area with asphalt due to a rougher surface and the chemical cross-linking between rubber particles and asphalt further strengthens their interaction. Therefore, there is a relatively stable blend system formed in modified asphalt, and its performance of modified asphalt has been improved.

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