scholarly journals A New Type of Crumb Rubber Asphalt Mixture: A Dry Process Design and Performance Evaluation

2020 ◽  
Vol 10 (1) ◽  
pp. 372
Author(s):  
Feng Ma ◽  
Jiasheng Dai ◽  
Zhen Fu ◽  
Jenny Liu ◽  
Wenhao Dong ◽  
...  

To obtain a crumb rubber asphalt mixture with excellent performance, this study combined trans-polyoctenamer rubber (TOR), crumb rubber, and other additives to establish a new type of crumb rubber (CRT). The objective of this study was to design and evaluate the road performance of the new type of crumb rubber asphalt mixture (CRTAM) with a skeleton dense texture through a dry process. First, the skeleton intrusion compact volume method was used to optimize the grading of coarse and fine aggregates, and the design of the CRTAM gradation was carried out through the same and unequal volume replacement grading method. Then, three types of road performance were analyzed: high-temperature stability, low-temperature crack resistance, and water stability. The results showed that 2% and 2.5% CRT met a low-temperature index with equal volume substitution, and the six gradations obtained by unequal volume replacement with 2% CRT complied with the requirements of a skeleton dense texture. When the substitution ratio was 1.5 and 0.5, the high-temperature performance was better. In addition, when the substitution ratio was 0.5, the flexural strain energy density was the highest and the low-temperature performance was the best. Including considerations of economic benefits, it is recommended that the CRT content be 2% and the substitution ratio be 0.5.

2015 ◽  
Vol 1095 ◽  
pp. 276-279
Author(s):  
Xin Feng Zhou ◽  
Xi Juan Xu

Through the research of different separation and regeneration aggregate content, different types of regenerative high temperature stability, low temperature performance and water stability performance of asphalt mixture comprehensively, the results show that: with the increase of recycled aggregate content, improves the high temperature properties of recycled asphalt mixture, low temperature performance and water stability are reduced, the admixture when regeneration aggregate is 20 ~ 25%, recycled asphalt mixture has good road performance. Key words: road engineering;waste asphalt mixture;separation and regeneration aggregate;road performance


Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1145
Author(s):  
Wei Li ◽  
Sen Han ◽  
Xiaokang Fu ◽  
Ke Huang

The aims of this paper are to prepare disintegrated high volume crumb rubber asphalt (DHVRA) with low viscosity, good workability and low-temperature performance by adding disintegrating agent (DA) in the preparation process, and to further analyze the disintegrating mechanism and evaluated high-temperature and low-temperature rheological properties. To obtain DHVRA with excellent comprehensive performance, the optimum DA dosage was determined. Based on long-term disintegrating tests and the Fluorescence Microscopy (FM) method, the correlations between key indexes and crumb rubber (CR) particle diameter was analyzed, and the evaluation indicator and disintegrating stage division standard were put forward. Furthermore, Fourier transform infrared spectroscopy (FT-IR) and Gel Permeation Chromatography (GPC) was used to reveal the reaction mechanism, and the contact angle test method was adopted to evaluate the surface free energy (SFE). In addition, the high-temperature and low-temperature rheological properties were measured, and the optimum CR content was proposed. Results indicated that the optimum DA dosage was 7.5‰, and the addition of DA promoted the melt decomposition of CR, reduced the viscosity and improved the storage stability. The 135 °C rotational viscosity (RV) of DHVRA from mixing for 3 h could be reduced to 1.475 Pa·s, and the softening point difference was even less than 2 °C. The linear correlation between 135 °C RV and the diameter of CR particle in rubber asphalt system was as high as 0.968, and the viscosity decay rate (VDR) was used as the standard to divide the disintegrating process into a fast disintegrating stage, stable disintegrating stage and slight disintegrating stage. Compared to common rubber asphalt (CRA), DHVRA has an absorption peak at 960 cm−1 caused by trans olefin = C-H, and higher molecular weight and polar component of surface energy. Compared with CRA, although the high-temperature performance of DHVRA decreases slightly, the low-temperature relaxation ability can be greatly improved.


2013 ◽  
Vol 477-478 ◽  
pp. 1175-1178
Author(s):  
Ling Zou ◽  
Jing Wei Ne ◽  
Weng Gang Zhang

70# and 90# matrix asphalt mixture with MaR were studied through dynamic modulus test, rutting test, freeze-thaw splitting test, bending test to study the applicability of the Modifying agent of rubber plastic compound (MaR) in matrix asphalt mixture.Test results were Compared with SBSI-C modified asphalt mixture.The results indicate that: high-temperature stability of MaR+70# asphalt mixture is as well as SBSI-C modified asphalt mixture,and is bettere than MaR+90# asphalt mixture; water stability of MaR+90# asphalt mixture is bettere than SBSI-C modified asphalt mixture and MaR+70# asphalt mixture; low temperature performance of MaR+90# asphalt mixture is bettere than MaR+70# asphalt mixture, but is worse than modified asphalt mixture SBSI-C ; MaR+70# asphalt mixture can be first used in area of resisting high temperature and rutting, MaR+90# asphalt mixture can be used if the water stability performance and low temperature performance are considered.


2012 ◽  
Vol 251 ◽  
pp. 436-441 ◽  
Author(s):  
Wei Liu

The warm mix regeneration technology has prominent economical efficiency that can not only reduce the secondary aging of new asphalt and old asphalt in RAP materials during the production process, but also improve the use proportion of RAP materials. As for the increase of RAP dosage and the warm mix additive added to influence the plant regenerated asphalt mixture performance, this paper adopts two kinds of warm mix additive for the test and analysis of the warm mix regenerated asphalt mixture performance with 20% and 60% RAP. The results indicate that magnify the proportion of RAP percentage makes contribution to further improve high-temperature performance of the regenerated mixture, but it has adverse effects on water resistant damage performance and low-temperature performance. At the same time, adopting the warm mix additive can significantly reduce the adverse effect, so warm mix regenerated technology has better feasibility.


2013 ◽  
Vol 734-737 ◽  
pp. 2287-2291 ◽  
Author(s):  
De Dong Guo

Fiber asphalt concrete has been more and more widely used in highway construction. For analyzing high and low temperature performance of fiber asphalt mixture, rheological properties of fiber asphalt mortar were studied through indoor test. Impact of Rheological properties of the fiber asphalt mortar on high temperature and low temperature properties of asphalt mixture was analyzed. Results showed that the larger fiber content was, the better performance of asphalt mixture's high temperature stability, fiber asphalt mortar rut factor and rutting tests results of asphalt mixture were linear correlation, reflecting the high temperature performance of asphalt mixture; With the increase of fiber content, variation of stiffness modulus, creep rate indicators and mixture low temperature performance was consistent, and rheological properties of fiber asphalt mortar could characterize low temperature performance of asphalt mixture.


2019 ◽  
Vol 136 ◽  
pp. 03010
Author(s):  
Ma Qingna ◽  
Zhao Zhiqin ◽  
Xu Qian ◽  
Sun Feng

Adding sulphur dilution asphalt modifier SEAM to asphalt mixture is not only a modifier of asphalt mixture, but also an additive of asphalt mixture. When the modifier is added into the asphalt mixture, the road performance of the asphalt mixture can be improved. This paper studies SEAM modified asphalt mixture the Marshall property index, temperature stability, Water stability and fatigue feature in the Laboratory. On the based of the result of the experiment and analysis, SEAM can improve the high temperature stability, Water stability and fatigue feature. But the low temperature stability can’t improve.


Coatings ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1070
Author(s):  
Cheng Xu ◽  
Zhengqi Zhang ◽  
Feifei Liu

To improve the low-temperature performance of RET (Reactive Elastomeric Terpolymer) modified asphalt mixture (RETM), polyurethane prepolymer (PUP) was used by wet process, ground waste rubber (GWR) and fibers were used by dry process. Tests of force ductility, bending beam rheometer (BBR), differential scanning calorimeter (DSC), viscosity and multiple stress creep recovery (MSCR) were conducted to study the effects of PUP on the performance of RET modified asphalt (RETA), and beam bending test was conducted to study the effects of GWR and fibers on the performance of RETM. Then, tests of beam bending, wheel tracking, Marshall immersion, freeze-thaw splitting, and economic analysis were further conducted to compare the performance and economy of RETM modified with optimum modifiers suggested. All modifiers improve the low-temperature performance of RETM. PUP content, the content and size of GWR and the content and type of fibers significantly affect the performance of RETA or RETM respectively. After analysis, 10% PUP, 2.1% 80 mesh GWR and 0.2% polyester (PE) fiber are considered as the optimum modifiers, respectively. Comparison results show that optimum modifiers variously improve the low-temperature performance, rutting resistance and moisture susceptibility of RETM, but they slightly reduced the economy of RETM. Comprehensive evaluation shows that 2.1% 80 mesh GWR and 10% PUP are better than 0.2% PE fiber.


Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4910
Author(s):  
Ping Zhang ◽  
Lan Ouyang ◽  
Lvzhen Yang ◽  
Yi Yang ◽  
Guofeng Lu ◽  
...  

As environmentally friendly materials, carbon black and bio-oil can be used as modifiers to effectively enhance the poor high-temperature and low-temperature performance of base asphalt and its mixture. Different carbon black and bio-oil contents and shear time were selected as the test influencing factors in this work. Based on the Box–Behnken design (BBD), carbon black/bio-oil composite modified asphalt was prepared to perform the softening point, penetration, multiple stress creep and recovery (MSCR), and bending beam rheometer (BBR) tests. The response surface method (RSM) was used to analyze the test results. In addition, the base asphalt mixtures and the optimal performance carbon black/bio-oil composite modified asphalt mixtures were formed for rutting and low-temperature splitting tests. The results show that incorporating carbon black can enhance the asphalt’s high-temperature performance by the test results of irrecoverable creep compliance (Jnr) and strain recovery rate (R). By contrast, the stiffness modulus (S) and creep rate (M) test results show that bio-oil can enhance the asphalt’s low-temperature performance. The quadratic function models between the performance indicators of carbon black/bio-oil composite modified asphalt and the test influencing factors were established based on the RSM. The optimal performance modified asphalt mixture’s carbon black and bio-oil content was 15.05% and 9.631%, and the shear time was 62.667 min. It was revealed that the high-temperature stability and low-temperature crack resistance of the carbon black/bio-oil composite modified asphalt mixture were better than that of the base asphalt mixture because of its higher dynamic stability (DS) and toughness. Therefore, carbon black/bio-oil composite modified asphalt mixture can be used as a new type of choice for road construction materials, which is in line with green development.


2013 ◽  
Vol 834-836 ◽  
pp. 252-258
Author(s):  
Peng Ren ◽  
Bo Zhang ◽  
Ya Qiao Wang ◽  
Lu Zhang ◽  
Lin Zhao

Three kinds of combination schemes were designed about SMA-13 asphalt mixture. They were basalt aggregate SMA, limestone aggregate SMA, basalt and limestone aggregate SMA. Through the study of low temperature and high temperature test of three kinds of combination, the low temperature performance of basalt and limestone aggregate SMA was better than that of the basalt aggregate SMA; and the high temperature performance was in between, thus providing important experimental data for the limestones replacing basalt in SMA pavement.


2011 ◽  
Vol 204-210 ◽  
pp. 2075-2078
Author(s):  
Hao Li ◽  
Rui Zhou ◽  
Xuan Cang Wang

In order to improve the pavement performance of reclaimed asphalt mixture, using Marshall test, rutting test, splitting test and long-term aging test, taking stability, dynamic stability, fatigue strength, stiffness modulus, and freeze-thaw splitting tension strength as the target, the influence law of old asphalt mixture content and regenerant content on pavement performance of reclaimed asphalt mixture is systematically studied. The results show that: the proportion of old asphalt mixture has no influence on high temperature performance of reclaimed asphalt mixture. With the proportion of old mixture increases, the optimum asphalt-aggregate ratio, low temperature performance, water stability, and anti-aging property of reclaimed asphalt mixture decrease. Addition of regenerant improves the low temperature performance of reclaimed asphalt mixture, and reduces the strength and high temperature stability of reclaimed asphalt mixture. Research results have great guiding significance for old asphalt mixture content selection, regenerant content selection and improving pavement performance of reclaimed asphalt mixture.


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