Research on the Pavement Performance of Recycled Asphalt Mixture Processed by Microwave

2010 ◽  
Vol 148-149 ◽  
pp. 987-993
Author(s):  
Song Qing Zhu ◽  
Jin Fei Shi ◽  
Fei Hao

In order to evaluate the pavement performance of recycled asphalt mixture processed by microwave, an experimental method was designed to compare the microwave heating with the conventional heating in recycling affection of asphalt mixture. The samples AC-13 were produced. Conventional and microwave heating performance of modified asphalt recycling test including the rutting test, the trabecular cold bending test, the Marshall immersion test, the freeze-thaw split test, and the splitting strength mechanical properties were test. The experimental results show that it is roughly the same in the high temperature stability and mechanical properties of these two areas, and at low temperature cracking resistance the use of microwave processing can improve the low temperature flexibility to reduce the surface temperature seasonal prone temperature shrinkage cracks and fatigue cracks. The stability on the water by using microwave processing can enhance the asphalt and aggregate adhesion so that mixture enhanced resistance to water damage, there is a better role in improving the water stability. These results could promote microwave recycling and provide the basis for the promotion applications.

Coatings ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 813 ◽  
Author(s):  
Bowen Guan ◽  
Jianan Liu ◽  
Hua Zhao ◽  
Jiayu Wu ◽  
Jingyi Liu ◽  
...  

This article is intended to investigate the microwave heating performance of asphalt mixtures containing magnetite powders (MPAM). For this purpose, the surface temperatures of asphalt mixtures containing different dosages of magnetite powders were measured during microwave heating. The low-temperature bending test and water sensitivity test were also conducted to evaluate the performance of MPAM. Heating rate and reflection loss of different thicknesses of MPAM were determined using a microwave heating test and arch reflectivity test, respectively. The results showed that because its main components are triiron tetroxide and iron oxide, which have excellent microwave-absorbing properties, magnetite powders can be used as microwave absorbers to improve the ability of microwave absorption and increase the heating rate of asphalt mixtures. The heating rate of the asphalt mixtures increased with the increase of the amount of magnetite powder. The addition of magnetite powder improved the low-temperature properties of the asphalt mixture, but it reduced the water stability of the asphalt mixture. Considering that the microwave-absorbing asphalt mixture used for melting snow and ice should have good water stability, the recommended dosage of magnetite powders was 60%. The microwave-absorbing properties of MPAM were related to its thickness in the pavement structure and frequency of microwaves. In order to greatly enhance the absorbing efficiency, future work should be focused on matching thickness and matching frequency.


2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Ying Xu ◽  
Zhijing Chou ◽  
Yunze Li ◽  
Jie Ji ◽  
Shi-fa Xu

In this study, the influence of the blending degree between virgin and aged binder on the pavement performance of hot-mix recycled asphalt mixture (HMRAM) with high RAP content is analyzed. The aggregate gradation of AC-16 was selected. The RAP contents were 30, 40, and 50%. HMRAMs with different degrees of blending (DOBs) were prepared by changing the mixing temperature (150, 165, and 180°C) without the occurrence of excessive aging for asphalt binders. An improved Hirsch dynamic modulus prediction model was then used to quantitatively characterize the DOB of HMRAM. Finally, the high-temperature, low-temperature, moisture stability, and fatigue resistance performance of HMRAM were tested and the effect of the DOB between the virgin and aged asphalt binder on the pavement performance was analyzed. The results showed that the DOB between the virgin and aged asphalt binder cannot reach 100% at the three mixing temperatures for HMRAM with 30, 40, and 50% RAP contents, which is inconsistent with the assumption of complete blending in China’s specification. The dynamic stability of the mixture gradually decreases with the increased DOB for HMRAM with a high RAP content, while the moisture stability, low-temperature, and fatigue resistance performance are continuously improved. This means that with the increase in DOB in the stage of open to traffic, meeting high-temperature performance criteria at the design stage may become unsatisfactory for HMRAM. The moisture stability, low-temperature performance, and fatigue resistance performances of HMRAM measured at the design stage were reasonable and conservative. The change in DOB significantly affects the content and properties of total free binder in HMRAM, affecting pavement performance. The content and physical properties of the RAP aggregate also have a significant impact on pavement performance.


2022 ◽  
Vol 2152 (1) ◽  
pp. 012005
Author(s):  
Peng Yin ◽  
Yuanguang Xie ◽  
Huixi Lang

Abstract Different binder content to RAP Regeneration SBS modified asphalt mixture for road performance to SBS modified asphalt (I-D type) as an index, determine the optimum dose of new heat regenerating agent and different RAP regeneration, and prepared different recycled asphalt, which have differences in RAP content. The performance of recycled asphalt mixture with different RAP content was evaluated by freeze-thaw splitting test. Rut test and Low temperature trabecular bending test. The correlation between RAP content and pavement performance was analyzed by grey system correlation analysis method. According to the experimental verification results, it can be known that increasing the content of RAP material can improve the high-temperature performance of reclaimed asphalt, but will result in a qualitative decrease in low-temperature performance and water temperature, but the above-mentioned performance can reach the required level, Shows that new heat regenerators play a role in the road performance of RAP materials, and for the RAP material utilization ratio of more than 50%, as for the gray correlation analysis, it can be found that there is a close correlation between the low-temperature performance of recycled asphalt mixture and the content of RAP material. The low temperature cracking resistance of asphalt mixtures will change significantly due to the slight changes in RAP materials.


2020 ◽  
Vol 39 (1) ◽  
pp. 45-53 ◽  
Author(s):  
Siwen Tang ◽  
Rui Wang ◽  
Pengfei Liu ◽  
Qiulin Niu ◽  
Guoqing Yang ◽  
...  

AbstractWith the concern of the environment, green dry cutting technology is getting more and more attention and self-lubricating tool technology plays an important role in dry cutting. Due to the demand for high temperature performance of tools during dry cutting process, cemented carbide with Ni3Al as the binder phase has received extensive attention due to its excellent high temperature strength and high temperature oxidation resistance. In this paper, WC-TiC-Ni3Al-CaF2 graded self-lubricating material and tools were prepared by microwave heating method, and its microstructure, mechanical properties and cutting performance were studied. Results show that gradient self-lubricating material can be quickly prepared by microwave heating technology, and the strength is equivalent to that of conventional heating technology. CaF2 not only plays a role in self-lubrication, but also refines the grain of the material. A reasonable gradient design can improve the mechanical properties of the material. When the gradient distribution exponent is n1 = 2, the material has high mechanical properties. Cutting experiments show that the WC-TiC-Ni3Al-CaF2 functional gradient self-lubricating tool has better cutting performance than the homogeneous WC-TiC-Ni3Al hard alloys.


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.


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.


2013 ◽  
Vol 361-363 ◽  
pp. 1851-1856 ◽  
Author(s):  
Lin Cao

AH-130 base asphalt graded according to the upper limit of AC-16 close gradation is selected in this paper to identify the impact of asphalt mortar of different filler-bitumen ratios on asphalt mixture’s road performance through small beam bending test at low temperature. And then bending failure energy, in substitute of bending strength, bending strain, is used to evaluate the anti-cracking performance of asphalt mixture at low temperature.


2010 ◽  
Vol 168-170 ◽  
pp. 1145-1148 ◽  
Author(s):  
Xin Qiu ◽  
Lan Yun Chen ◽  
Liang Xue

The paper investigates the effects of different concentrations of crumb rubber (CR) on the pavement performance of the conventional penetration-grade 80/100 bitumen and the dense-graded wearing course asphalt mixture (AC16). A wet process and 0.6mm size CR were used and the control variables included three types of CR of concentrations 5%,10% and 15% by total weight of binder. The evaluations were twofold. Firstly, a comparison of the basic and rheological properties of those modified and unmodified binders was conducted. Secondly, a comparison of the resistance to moisture damage, low temperature cracking and permanent deformation of the AC16 and CR modified AC16 was performed. The results show that all the CR modified binders and mixtures are found to have improved performance as evaluated by a series of laboratory tests. In addition, among three CR concentrations, AC16 modified with 10%CR by total weight of binder exhibits the most satisfactory performance properties with respect to the resistance to moisture damage, permanent deformation and low temperature cracking.


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