Effect of Shear Time and the Crumb Rubber Percentage on the Properties of Composite Modified Asphalt

2013 ◽  
Vol 848 ◽  
pp. 26-30
Author(s):  
Fu Qiang Dong ◽  
Wen Zhe Zhao ◽  
Yu Zhen Zhang ◽  
Hua Dong Sun ◽  
Wei Yu Fan ◽  
...  

This paper presents a laboratory study of Styrene-Butadiene-Styrene (SBS)/ crumb rubber modified asphalt by the two-step method. The conventional properties of the modified asphalt were determined. The effects of crumb rubber content and shearing time on the performance of the crumb rubber modified asphalt and composite modified asphalt. The results show that the crumb rubber contents and shearing time have significant impacts on the performance of the modified asphalt. With the crumb rubber content increasing, the high temperature performance was improved and the low temperature chanethe softening point increases and penetration decrease, and the ductility change little. It is comfortable for workability at the crumb rubber content of 20%. The viscosity is an important measurement for the workability of the modified asphalt. After adding the stabilizer, the viscosity increases until the shearing time reaching 1.5h, then it will decrease gradually.

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3780
Author(s):  
Jingyao Yang ◽  
Gang Xu ◽  
Peipei Kong ◽  
Xianhua Chen

With the growing interest in bituminous construction materials, desulfurized crumb rubber (CR)/styrene–butadiene–styrene (SBS) modified asphalts have been investigated by many researchers as low-cost environmental-friendly road construction materials. This study aimed to investigate the rheological properties of desulfurized CR/SBS composite modified asphalt within various temperature ranges. Bending beam rheometer (BBR), linear amplitude sweep (LAS), and multiple stress creep recovery (MSCR) tests were performed on conventional CR/SBS composite modified asphalt and five types of desulfurized CR/SBS modified asphalts. Meanwhile, Burgers’ model and the Kelvin–Voigt model were used to derive nonlinear viscoelastic parameters and analyze the viscoelastic mechanical behavior of the asphalts. The experimental results indicate that both the desulfurized CR/SBS composite modifier and force chemical reactor technique can enhance the crosslinking of CR and SBS copolymer, resulting in an improved high-, intermediate-, and low-temperature performance of desulfurized CR/SBS composite modified asphalt. Burgers’ model was found to be apposite in simulating the creep stages obtained from MSCR tests for CR/SBS composite modified asphalts. The superior high-temperature performance of desulfurized CR/SBS modified asphalt prepared with 4% SBS, 20% desulfurized rubber, and a force chemical reactor time of 45 min contributes to the good high-temperature elastic properties of the asphalt. Therefore, this combination is recommended as an optimal preparation process. In summary, the desulfurization of crumb rubber and using the force chemical reactor technique are beneficial to composite asphalt performance and can provide a new way of utilizing waste tire rubber.


2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Xueqian Li ◽  
Jianzhong Pei ◽  
Jiujian Shen ◽  
Rui Li

The high-performance asphalt materials are used to replace the ordinary road asphalt that cannot meet the requirements of natural environment and traffic situation, which is the effective way to solve poor asphalt pavement durability. In this paper, polyphosphoric acid- (PPA-) modified asphalt and polyphosphoric acid (PPA)/styrene-butadiene-styrene (SBS) composite-modified asphalt with different PPA content were prepared by using two-type asphalt. The effect of PPA modifier on asphalt was analyzed by using the creep elastic recovery rate, accumulating strain and creep modulus tests. The results showed that asphalt types and the PPA could significantly improve the elastic recovery rate of asphalt, reduce the cumulative strain and creep stiffness of the viscosity part, improve the high-temperature performance, and reduce the permanent deformation of the asphalt under repeated load. The high-temperature performance and low-temperature performance of PPA-modified asphalt were studied by the chemical and physical modification techniques. The advantages of modified asphalt are well developed while reducing the price of it, which has important technical and economic significance.


Materials ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2345 ◽  
Author(s):  
Yangsheng Ye ◽  
Gang Xu ◽  
Liangwei Lou ◽  
Xianhua Chen ◽  
Degou Cai ◽  
...  

In this study, a new type of composite modified bitumen was developed by blending styrene-butadiene-styrene (SBS) and crumb rubber (CR) with a chemical method to satisfy the durability requirements of waterproofing material in the waterproofing layer of high-speed railway subgrade. A pressure-aging-vessel test for 20, 40 and 80 h were conducted to obtain bitumen samples in different long-term aging conditions. Multiple stress creep recovery (MSCR) tests, linear amplitude scanning tests and bending beam rheometer tests were conducted on three kinds of asphalt binders (SBS modified asphalt, CR modified asphalt and SBS/CR composite modified asphalt) after different long-term aging processes, including high temperature permanent deformation performance, resistance to low temperature thermal and fatigue crack. Meanwhile, aging sensitivities were compared by different rheological indices. Results showed that SBS/CR composite modified asphalt possessed the best properties before and after aging. The elastic property of CR in SBS/CR composite modified asphalt improved the ability to resist low temperature thermal and fatigue cracks at a range of low and middle temperatures. Simultaneously, the copolymer network of SBS and CR significantly improved the elastic response of the asphalt SBS/CR modified asphalt at a range of high temperatures. Furthermore, all test results indicated that the SBS/CR modified asphalt possesses the outstanding ability to anti-aging. SBS/CR is an ideal kind of asphalt to satisfy the demand of 60 years of service life in the subgrade of high speed railway.


2013 ◽  
Vol 753-755 ◽  
pp. 734-740 ◽  
Author(s):  
Li Wan ◽  
Shao Peng Wu ◽  
Min Lei ◽  
Kim Jenkins

Currently, rejuvenator seal which is one of the preventive maintenance methods is more widely used due to its economic benefits and convenience. This paper described the chemical and rheological evaluation of the aged styrene butadiene styrene modified asphalt (ASMA) treated by two rejuvenator sealer materials (RSMs). First the ASMA was rejuvenated by mixing with the RSMs. Then the ASMA and two rejuvenated binders were re-aged by 10h PAV test. At last, the new binder, ASMA, rejuvenated ASMAs, re-aged binders were tested by Dynamic shear rheometer (DSR) and Fourier Transform Infrared Spectroscopy (FTIR). The results showed that the first aging of the new binder had a significant decrease of the low temperature performance and slight improvement of the high temperature performance. In addition, the high temperature performance increased obviously after 10h PAV test. Two RSMs could significantly soften the aged binder due to increase of maltene content existing in the RSMs, and the rejuvenated binder exhibited a better low performance after the 10h PAV test. However they cannot restore the low temperature completely because that RSMs cannot remedy the degradation of SBS modifier and remove the carbonyl produced in the aging progress.


2013 ◽  
Vol 753-755 ◽  
pp. 715-718
Author(s):  
Xiu Hua Yang

SBS is a styrene - butadiene - styrene block copolymer, the addition of SBS of high and low temperature performance and road can be very good to improve the performance of asphalt. This paper studied the performance of the modified asphalt on the content of modifier.


2017 ◽  
Vol 35 (6) ◽  
pp. 553-560 ◽  
Author(s):  
Sajad Rezaei ◽  
Mohammadvoriya Khordehbinan ◽  
Sayed-Mohammad-Reza Fakhrefatemi ◽  
Sasan Ghanbari ◽  
Mohammad Ghanbari

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Yafeng Gong ◽  
Yunze Pang ◽  
Fayang Li ◽  
Weidong Jin ◽  
Haipeng Bi ◽  
...  

The performance of asphalt can be improved by adding styrene-butadiene-styrene (SBS) copolymer and crumb rubber (CR). This paper investigated the influence of the structure and content of styrene-butadiene-styrene (SBS) copolymer on the properties of SBS/CR modified asphalt (SBS/CRMA). These SBS/CRMA were prepared by mixing 90# matrix asphalt, 60 mesh CR powder, and SBS copolymers with two molecular structures, which were tested for penetration, softening point, ductility, and rheology. The complex modulus, phase angle, rutting factor, storage modulus, and dissipation modulus of SBS/CRMA were analyzed with the 64°C frequency sweep tests. The results revealed that the content and structure had significant impacts on the performances of SBS/CRMA, and the advantages of SBS polymer network structure in the modified asphalt system cannot be reflected when the amount of SBS was small. Meanwhile, the high-temperature stability, low-temperature tensile resistance, temperature sensitivity, and viscoelasticity of rubberized asphalt were further improved by adding a moderate amount of SBS copolymer. Furthermore, the properties of SBS/CRMA were better as the contents of SBS increased when the type of SBS doped was the same. The effect of modification improved by star-shaped SBS copolymer addition was more than that improved by linear SBS copolymer addition. As a conclusion, the content of 4 wt% star-shaped SBS and 20 wt% CR powder-modified 90# matrix asphalt has the best modification effect with the comparison of other groups.


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