Research on Microstructure and Low Temperature Properties of Polymer Modified Asphalt

2015 ◽  
Vol 1094 ◽  
pp. 253-260
Author(s):  
Lan Wang ◽  
Yong Jie Jia ◽  
Lei Feng
Keyword(s):  
Low Temperature ◽  
Aging Effect ◽  
Crumb Rubber ◽  
Rubber Powder ◽  
Modified Asphalt ◽  
Macroscopic Structure ◽  
Before And After ◽  
Creep Stiffness ◽  
Distribution State ◽  
Polymer Modified Asphalt

In view of three kinds of polymer modified asphalt, Compound rubber powder modified asphalt, rubber powder modified asphalt and SBS modified asphalt, were commonly used in the Inner Mongolia region, scanning electron microscope (SEM) were used to observe the macroscopic structure morphology of asphalt before and after aging , getting the influence of aging effect on modifier’s distribution state in asphalt and interface combination properties between the asphalt, that is, after aging, three kinds of modifier and asphalt interface characteristic deterioration. By using bending beam rheometer (BBR) three kinds of asphalt after aging were conducted trabecular bending creep experiments under different temperature, through analyzing the changing rules of bending creep stiffness modulus S and the value of m, it can be get that: composite rubber powder modified asphalt has the best low temperature performance , followed by the crumb rubber modified asphalt.

Research on the Microstructure and Performance of Asphalt after the Salt Freezing Cycle

2014 ◽  
Vol 575 ◽  
pp. 238-244 ◽  
Author(s):  
Ji Wei Han ◽  
Ya Nan Cui ◽  
Zhen Li ◽  
Chao Li ◽  
Zhen Zheng Liu
Keyword(s):  
Low Temperature ◽  
Rubber Powder ◽  
Modified Asphalt ◽  
Temperature Performance ◽  
Before And After ◽  
Freezing Cycle ◽  
And Performance ◽  
Asphalt Concrete Pavement ◽  
Styrene Butadiene ◽  
Sbs Modified Asphalt

About more than 90% highway have adopted asphalt concrete pavement in China. A lot of quality problems appeared in the highway pavement due to freezing-thawing circulations under the condition of low temperature. The scanning electron microscope (SEM) was utilized to observe the microstructure of styrene-butadiene-styrene (SBS) modified asphalt and rubber powder modified asphalt before and after the salt freezing. Also three routine indicators (penetration, softening point and ductility) for the two kinds of asphalt were tested before and after the salt freezing. The analysis results showed that the temperature susceptibility of SBS modified asphalt and rubber powder modified asphalt were all increased and the high temperature performance and low temperature performance of both asphalt were reduced after the salt freezing cycles as the same time the performance of rubber modified asphalt after salt freezing cycle was superior to SBS modified asphalt by comparing the basic indicators of them.

scholarly journals Aging Properties and Mechanism of Microwave-Activated Crumb Rubber Modified Asphalt Binder

2020 ◽  
Vol 7 ◽  
Author(s):  
Tao Zhou ◽  
Jianing Zhou ◽  
Qidong Li ◽  
Bo Li
Keyword(s):  
Functional Group ◽  
Asphalt Binder ◽  
Molecular Size ◽  
Gel Permeation Chromatography ◽  
Aging Effect ◽  
Microwave Treatment ◽  
Crumb Rubber ◽  
Microwave Activation ◽  
Modified Asphalt ◽  
Before And After

Although crumb rubber modified asphalt (CRMA) has a better performance than matrix asphalt (MA) in road engineering, the application bottlenecks of this material lies in its high viscosity, poor workability and bad storage stability. Microwave technology is one of the solutions to the above problems. The objective of this study was to investigate the physical and chemical changes before and after aging of CRMA which was prepared by microwave activated crumb rubber, and the aging mechanism of microwave-activated crumb rubber modified asphalt (MACRMA). Through penetration, softening point, ductility, viscosity and DSR test, the high and low temperature performance and temperature sensitivity of MA, CRMA and MACRMA before and after aging were studied. These tests results revealed that microwave treatment can improve the anti-rutting ability and the anti-aging performance of rubber asphalt. According to gel permeation chromatography (GPC) test, the distribution changes of the internal molecular content of the three asphalts were determined during the aging process. Its test results showed that aging effect accelerated the conversion of small molecules to large molecules in asphalt, and the value of large molecular size (LMS) increases more after long-term aging. The microwave activation made the swelling reaction more intense, thereby delayed the conversion of LMS in the rubber asphalt. In addition, LMS has a high correlation with test indicators. The fourier transform infrared spectroscopy (FTIR) test was used to measure the functional group changes of each asphalt. The FTIR spectra indicated that microwave activation is mainly a process of physical change. The carbonyl and sulfoxide functional group indices of MACRMA were lower than those of MA and CRMA, which also confirmed that MACRMA has a better anti-aging ability.

Low temperature and fatigue characteristics of treated crumb rubber modified asphalt after a long term aging procedure

2019 ◽  
Vol 234 ◽  
pp. 1262-1274 ◽  
Author(s):  
Zixuan Chen ◽  
Tao Wang ◽  
Jianzhong Pei ◽  
Serji Amirkhanian ◽  
Feipeng Xiao ◽  
...  
Keyword(s):  
Low Temperature ◽  
Crumb Rubber ◽  
Modified Asphalt ◽  
Fatigue Characteristics

scholarly journals Research on the Properties of Low Temperature and Anti-UV of Asphalt with Nano-ZnO/Nano-TiO2/Copolymer SBS Composite Modified in High-Altitude Areas

2020 ◽  
Vol 2020 ◽  
pp. 1-15 ◽  
Author(s):  
Xiangbing Xie ◽  
Tao Hui ◽  
Yaofei Luo ◽  
Han Li ◽  
Guanghui Li ◽  
...  
Keyword(s):  
Surface Modification ◽  
High Temperature ◽  
Low Temperature ◽  
Orthogonal Test ◽  
Nano Zno ◽  
Carbonyl Index ◽  
Modified Asphalt ◽  
Temperature Performance ◽  
Before And After ◽  
Sbs Modified Asphalt

Strong ultraviolet light and low-temperature are the typical environmental characteristics in high-altitude areas. The performance of SBS-modified asphalt in the above environmental characteristics needs further study. To improve the resistance ultraviolet (UV) ageing and low-temperature performance of copolymer- (SBS-) modified asphalt, an SBS-modified asphalt containing nano-ZnO and nano-TiO2 is proposed. In this paper, nano-ZnO, nano-TiO2, and SBS were used as modifiers with the silane coupling agent (KH-560) as the nanomaterial surface modification. The orthogonal test table was used to analyse the effects of the three modifiers on the physical properties of modified asphalt at different dosages. On this basis, the physical properties, low-temperature properties, and ageing indices (carbonyl index and sulfoxide index) were studied for base asphalt, SBS-modified asphalt, nano-ZnO/SBS-modified asphalt, and nano-ZnO/nano-TiO2/SBS composite-modified asphalt before and after photoaging. The content changes of characteristic elements (Zn and Ti) in the nano-ZnO/nano-TiO2/SBS composite-modified asphalt before and after ageing were studied by scanning electron microscopy with energy dispersive spectroscopy (SEM/EDS), and the UV ageing mechanism was revealed. The results indicate that two nanoparticles show the best compatibility with asphalt after surface modification and can improve the binding ability between SBS and base asphalt. The orthogonal test analysis shows that nano-ZnO has a highly significant effect on the low- and high-temperature performance of the nano-ZnO/nano-TiO2/SBS composite-modified asphalt, and nano-TiO2 has a significant effect on the high-temperature performance. Three optimal composite-modified systems for base asphalt including 4% nano-ZnO/1.5% nano-TiO2/3.2% SBS were proposed and had the best antiaging ability. Compared with the sulfoxide index, the carbonyl index changed most obviously before and after ageing. Additionally, the results reveal that nano-TiO2 has a good absorption effect at a wavelength of 365 nm (ultraviolet light), while nano-ZnO is liable to photolysis, and its activity decreases at this wavelength.

scholarly journals Evolution of Rheological Behaviors of Styrene-Butadiene-Styrene/Crumb Rubber Composite Modified Bitumen after Different Long-Term Aging Processes

Materials ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2345 ◽  
Author(s):  
Yangsheng Ye ◽  
Gang Xu ◽  
Liangwei Lou ◽  
Xianhua Chen ◽  
Degou Cai ◽  
...  
Keyword(s):  
Low Temperature ◽  
High Speed ◽  
Crumb Rubber ◽  
Modified Bitumen ◽  
High Speed Railway ◽  
Modified Asphalt ◽  
Styrene Butadiene Styrene ◽  
Styrene Butadiene ◽  
Butadiene Styrene

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.

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 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 Research on the Influence of Nanocarbon/Copolymer SBS/Rubber Powder Composite Modification on the Properties of Asphalt and Mixtures

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Wenhui Zhao ◽  
Xiangbing Xie ◽  
Guanghui Li ◽  
Jiuguang Geng ◽  
Meng Bao ◽  
...  
Keyword(s):  
Low Temperature ◽  
Asphalt Mixture ◽  
Temperature Stability ◽  
Powder Composite ◽  
High Temperature Stability ◽  
Rubber Powder ◽  
Modified Asphalt ◽  
Modification Process ◽  
Low Temperature Cracking ◽  
Surface Modified

To expand the application range of modified asphalt and mixtures and effectively reduce the aggregation of nanomaterials in asphalt, nanocarbon/styrene butadiene styrene (SBS)/rubber powder composite-modified asphalt is proposed. This paper presents a laboratory study on the performance of nanocarbon/copolymer SBS/rubber powder composite-modified asphalt, and nanocarbon particles modified by titanate coupling agents as modifiers are selected. The nanocarbon/copolymer SBS/rubber powder composite-modified asphalt was prepared by a high-speed shearing method. The physical properties and rheological performance were assessed using ductility tests, softening point tests, penetration tests, dynamic shear rheometer (DSR) tests, and bending beam rheometer (BBR) tests. Furthermore, the mixture properties, including the high-temperature stability, low-temperature cracking resistance, moisture stability, and freeze-thaw splitting, were evaluated in the laboratory. The micromorphology of the base asphalt and composite-modified asphalt was examined by scanning electron microscopy (SEM), and the reactions between the modifiers and AH-70 base asphalt were studied by Fourier transform infrared spectroscopy (FTIR). The results reveal that the surface-modified nanocarbon and rubber powder additives substantially increased the softening point and penetration index of the base asphalt, with little obvious influence on the low-temperature performance. In addition, when nanocarbon/copolymer SBS/rubber powder composite-modified asphalt was used, the high-temperature stability and low-temperature cracking resistance of the nanocarbon/copolymer SBS/rubber powder composite-modified asphalt mixture were approximately 1.3 times those of the nanocarbon/rubber powder asphalt mixture. In terms of the micromorphology and reaction, the addition of the nanocarbon can increase the compatibility between the base asphalt and rubber powder, and then the addition of copolymer SBS can improve the structure of nanocarbon (after surface modification)/rubber powder-modified asphalt to form a stable network. Moreover, the physical reaction plays the dominant role in the modification process for the rubber powder and base asphalt, and chemical reactions occur in the modification process for the surface-modified nanocarbon and base asphalt.

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.

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