scholarly journals Performance Evaluation of Asphalt Rubber Mixture with Additives

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1200 ◽  
Author(s):  
Cheng ◽  
Liu ◽  
Ren ◽  
Huang

Crumb rubber, as a recycled material used in asphalt mixture, has gained more attention in recent years due to environmental benefits and the advantages of its pavement, such as excellent resistance to cracking, improved durability, less road maintenance, lower road noise, etc. However, the high-temperature performance of mixture with crumb rubber does not perform well. In order to improve the performance, this paper examined the effect of additives on the laboratory performance of asphalt rubber Stone Matrix Asphalt (AR-SMA) with additives. Three groups of AR-SMA: no additives, Styrene–Butadiene–Styrene (SBS) and Granular Polymer Durable additive (GPDa) were included, with no additives as a control group. Each group was investigated at three asphalt rubber content (ARC): 6.4%, 6.9%, 7.4% with regard to high-temperature and fatigue properties. The results show that with increasing ARC, the high-temperature performance of mixture without additive decreases, and the high-temperature performance increases first and then decreases for SBS and GPDa. Moreover, the rutting resistance of AR-SMA with GPDa at 6.9% ARC performs best. Under the condition of mixtures with appropriate ARC, AR-SMA with GPDa has higher fatigue life and sensitivity to fatigue cracking than the control group. Simultaneously, the fatigue performance of AR-SMA with GPDa is not as significant as that without additive with increasing ARC. In a word, GPDa is a good choice to improve the performance of AR-SMA. However, it should be noted that optimal asphalt content of AR-SMA mixtures with GPDa is higher than that of traditional mixtures.

2021 ◽  
pp. 247-253
Author(s):  
Haibin Li ◽  
Mingming Zhang ◽  
Ahmed Abdulakeem Temitope ◽  
Hongjun Jing ◽  
Guijuan Zhao ◽  
...  

Alloy Digest ◽  
1987 ◽  
Vol 36 (7) ◽  

Abstract AL TECH POTOMAC A has well-balanced strength and toughness which make it especially suitable for a wide variety of hot-die steel applications, including those involving severe coolants. Its outstanding mechanical properties make it useful for many non-tooling requirements such as aerospace components. For more specialized needs, the manufacturer offers special melting processes that enhance this steel's fatigue properties and transverse tensile ductility. This datasheet provides information on composition, physical properties, microstructure, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on high temperature performance as well as forming, heat treating, and machining. Filing Code: TS-478. Producer or source: AL Tech Specialty Steel Corporation.


Alloy Digest ◽  
1998 ◽  
Vol 47 (2) ◽  

Abstract Incoloy Alloy 864 is a high performance alloy developed specifically for automotive exhaust system flexible couplings and other exhaust applications. The alloy has a good combination of oxidation and corrosion resistance, with good mechanical strength, stability, and fatigue properties. This datasheet provides information on composition, physical properties, and elasticity. It also includes information on high temperature performance and corrosion resistance as well as joining. Filing Code: SS-708. Producer or source: Inco Alloys International Inc.


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.


2020 ◽  
Vol 10 (16) ◽  
pp. 5447
Author(s):  
Haibin Li ◽  
Wenbo Li ◽  
Ahmed Abdulakeem Temitope ◽  
Dong Zhao ◽  
Guijuan Zhao ◽  
...  

Asphalt rubber (AR) is often described as an environmentally friendly material due to the incorporation of recycled rubber from used tires and its improved service life. Its field application is influenced by many factors. In order to evaluate the impact of different factors such as crumb rubber (CR) content, stabilizer and the production method on the performance of rubber powder modified asphalt, two different matrix asphalts were prepared, the basic experiments, control variable methods and several related tests were thereafter conducted. The results showed that a moderate amount of CR could enhance the pavement performance. The suitable CR content was 20–25% for 90# matrix asphalt and 22–26% for 70# matrix asphalt. The stabilizer had a positive impact on the AR’s high temperature behavior and was beneficial to the storage of AR, but it did not make a significant influence on low temperature behavior. In addition, different methods brought certain performance differences. Though AR produced with the heat fusion method had better high-temperature performance, the rubber particles would easily disperse and melt in the asphalt during the shearing process, which gave AR more balanced physical performance. This study identifies the shearing method as the optimal choice for site construction and provides a wider application range for asphalt rubber in the road construction field. The selection of parameters depends on the construction areas and performance requirements.


2020 ◽  
Vol 10 (2) ◽  
pp. 272-277 ◽  
Author(s):  
Bo Li ◽  
Xuwei Zhu ◽  
Xingjun Zhang ◽  
Xiaolong Yang ◽  
Xiuli Su

Crumb rubber pretreatment by microwave before blending with an asphalt matrix can address and improve the modification problem of of crumb rubber modifier (CRM) asphalt plant. In this research, the surface area and microstructure of microwave activated CRM and high-temperature performance of CRM asphalt were investigated to characterize the mechanism of interaction between activated CRM blends added and base asphalt. The surface area and microstructure of CRM were measured by gas adsorption method and the scanning electron microscopy (SEM) respectively when CRM was activated using microwave treatment time (30 s, 60 s, 90 s, 120 s and 150 s). The complex shear modulus (G*) and the phase angle (δ) of the CRM asphalt were measured by Dynamic Shear Rheometer (DSR) test. The results indicated that microwave treatment produced more porous structure and agglomeration phenomenon than control one for a given activated time of CRM. The flocculent structure was the most obvious one and agglomeration phenomenon was the most significant one for the particle surface microwave activated 90 s. The δ decreased and G* increased as CRM blends activated time increased before a certain time using the same frequency of microwave treatment. The G*/sinδ of CRM blends was the maximum when CRM activated for 90 s using microwave treatment. Both surface area and microstructure of the CRM influenced the high-temperature performance of CRM binders.


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.


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.


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