scholarly journals Mechanism of Polyurethane Binder Curing Reaction and Evaluation of Polyurethane Mixture Properties

Coatings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1454
Author(s):  
Min Sun ◽  
Yufeng Bi ◽  
Wei Zhuang ◽  
Sai Chen ◽  
Pinhui Zhao ◽  
...  

This study focuses on analyzing the curing reaction mechanism of polyurethane (PU) binders and comprehensively evaluating the PU mixture’s properties. The former was investigated by conducting a Fourier transform infrared spectroscopy (FTIR) test on PU binders with different curing times. The volume change characteristics, construction operation time, and strength formation law were clarified through the splitting tensile test of PU mixtures under different environmental conditions. The optimal PU mixture stacking time and curing time under different environmental conditions were determined. The properties of the PU mixture and asphalt mixture were evaluated and compared through a rutting test, low-temperature bending test, freeze–thaw splitting test, and four-point bending fatigue test. The results show that the physical and chemical curing of the PU binder occurred within the first 24 h of curing, and the reaction speed gradually accelerated to form a polyurea structure 24 h later. It is recommended to stack the PU mixture for 4 h before compaction and to cure it for 2 days before opening under the conditions of 50% humidity and 15–40 °C surrounding temperature. The PU mixture shows better temperature stability and fatigue resistance than the asphalt mixture, and the splitting tensile strength of the PU mixture before and after the freeze–thaw splitting test is also higher. It is clear that the PU mixture is a green road building material with good performance.

2014 ◽  
Vol 587-589 ◽  
pp. 1276-1280
Author(s):  
Xiang Fei Zhai

Through the freeze-thaw splitting test, rutting test, low temperature bending test, comprehensive analysis the affect of coarse and fine ratio on ATB asphalt mixture performance. The results showed that: the ratio of change have a significant effect on water stability, high temperature stability, low temperature stability. Reasonable coarse and fine ratio have a higher degree of stability; Smaller coarse and fine ratio can effectively improve the asphalt mixture water stable performance, with coarse and fine ratio increased, freeze-thaw splitting strength ratio decreases; Larger coarse and fine ratio have an adverse effect on the high temperature stability, dynamic stability after the first increase and then decrease with increasing coarse and fine ratio; Smaller coarse and fine ratio can significantly improve the low temperature stability.


2020 ◽  
Vol 12 (7) ◽  
pp. 2966 ◽  
Author(s):  
Chao Chai ◽  
Yong-Chun Cheng ◽  
Yuwei Zhang ◽  
Yu Chen ◽  
Bing Zhu

This paper focuses on the freeze-thaw cycles (F-T cycles) resistance of porous asphalt mixture (PAM) with different air voids in order to explore the gradation of the PAM suitable for seasonal freezing regions. Three sets of PAMs with 18%, 21%, and 25% air voids were designed. After 0–20 F-T cycles, the effects of F-T cycles on the performance degradation of three groups of PAMs were studied by performing a low-temperature splitting test with acoustic emission technology, a normal temperature splitting test, a compression test, a Cantabro particle loss test, and a dynamic creep test. The results show that the damage process of PAM caused by multiple F-T cycles could be more clearly defined by acoustic emission parameters. In addition, the larger the air void, the smaller its indirect tensile strength and compression strength, and the worse its particle loss resistance and high-temperature stability, which made the adverse effect of F-T cycles more significant. Therefore, the air void of PAM used in seasonal freezing regions is suggested to be less than 21%.


2012 ◽  
Vol 253-255 ◽  
pp. 607-610
Author(s):  
Yu Qing Yuan ◽  
Wei Li ◽  
Xue Chan Li ◽  
Tao Guo

To study the asphalt pavement performances on high temperature or its water stabilities, a series of tests, including high temperature stability test, immersion Marshall test, freeze-thaw splitting test, were finished. According to bailey method, initial quasi grading were calculated. Passing rate of 2.36 mm is respectively 36.3%, 33.1%, 36.1%, 38.7%, which is close to the initial quasi grading, namely 36%, 31.5%, 36%, 40%. Respectively at the test temperature of 60 °C, 68 °C, rutting tests were put forward. The results show that the mixture of gradation one has a higher temperature stability than the others in any case. Marshall immersion test and freeze-thaw test were conducted, optimizing with freeze-thaw splitting intensity ratio, which shows that the mixture of gradation one has a better water stability. To sum up, gradation one is recommended, designed by Marshall compaction molding with times of 100.


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.


2014 ◽  
Vol 1049-1050 ◽  
pp. 422-425
Author(s):  
Chao Peng ◽  
Jian Ying Yu ◽  
Jing Dai ◽  
Zhi Jie Zhao ◽  
Jing Yi Fu ◽  
...  

Effect of a chloride deicing additive (Cl-DIA) on the performance of asphalt mixture was investigated by evaluating the moisture, cracking and rutting resistance. Freeze-thaw splitting test result showed that asphalt mixture containing Cl-DIA weakened moisture resistance to some extent but it was still applicable for asphalt pavement. Wheel-tracking test indicated that Cl-DIA evidently improved the rutting resistance of the asphalt mixture and the weight concentration of Cl-DIA in asphalt mixture had to exceed 3%. Beam bending test implied that Cl-DIA did not help for the cracking of the asphalt mixture.


2013 ◽  
Vol 361-363 ◽  
pp. 1681-1688 ◽  
Author(s):  
Hai Sheng Zhao ◽  
Wei Chen ◽  
Xiao Yan Wang

This paper used one kind of organic additive LEADCAP to reduce the compacting temperature of SBS WMA mixture, and compared the WMA mixture compacted by superpave gyratory compactor (SGC) with HMA mixture to determine the compacting temperature of WMA mixture. Rutting test, low temperature bending test, freeze-thaw indirect tension test, Hamburg Wheel-Track test and dynamic modulus were carried out to evaluate the road performance of WMA mixed with LEASCAP. The test result showed that the WMA mixed with LEADCAP had well performed high temperature stability, low temperature stability, water stability, rutting cracking resistance, and high dynamic modulus, the compacting temperature were 127 °C, and affectively reduced the compacting temperature of SBS WMA mixture.


2012 ◽  
Vol 557-559 ◽  
pp. 329-333
Author(s):  
Zhong Run Zheng ◽  
Chao Zhao ◽  
Yi Feng Zhao ◽  
Pei Song

This paper introduces an asphalt mixture that mixed with different admixtures, rutting resistance agent and lignin fiber, at the same time. Rutting test and freeze-thaw splitting test are used to analyze rutting resistance on the high temperature and low temperature cracking of the asphalt mixture. The experiments with different mixes material composition are conducted to analysis various properties of the two admixtures on the mixture, especially the high temperature stability, low temperature crack resistance and the law of improvement effect. In addition, the experiments also determine the optimal asphalt content of different type of mixtures. The results showed that the single-doped KTL rutting resistance or lignin fibers have some improvement in water temperature performance of asphalt mixture, stability improvement of double-doped admixture asphalt mixture is better than the single-doped asphalt mixture, such as KTL rutting resistance agents and lignin fibers


2011 ◽  
Vol 243-249 ◽  
pp. 710-716 ◽  
Author(s):  
Ying Chun Cai ◽  
Yuan Xun Zheng

To study the influence of fiber on the water stability of asphalt mixtures, the optimum dosage of asphalt and fibers are studied by the method of Marshall test and rut test. The results demonstrate that the optimum dosage of asphalt and fibers are 4.63% and 0.30%, respectively. Then the improved effects of basalt fiber on water stability of asphalt mixtures are evaluated through immersed Marshall test and freeze-thaw splitting test according to related specifications. The results show that the freeze-thaw splitting strength and splitting strength without freeze-thaw of fiber-reinforced asphalt mixture are improved to some extent compared with control mixture. Splitting strength without freeze-thaw of basalt, polyester and xylogen fiber-reinforced asphalt mixture is increased by 36.4%, 15.4% and 6.2%, and freeze-thaw splitting strength is increased by 55.2%, 28.7% and 14.5%. It can be concluded that fiber can remarkably improved the water stability of asphalt mixtures, besides; the improvement effects of basalt fiber are superior to polyester fiber and xylogen fiber.


2013 ◽  
Vol 361-363 ◽  
pp. 1563-1566
Author(s):  
Chuan Yi Zhuang ◽  
Ya Li Ye ◽  
Yan Zhou

Types of asphalt mixture with different gradations and air voids were designed. Tests on their indirect tensile strength, compressive strength and resilient modulus of compression under single axle compressing were taken to study the effects of two forms of water immersion (hot water immersion and freeze-thaw split test) on asphalt mixtures mechanical performance and high temperature stability. Test results point out that water immersion decreased asphalt mixtures performance seriously and the effect of freeze-thaw split tests on asphalt mixtures performance is far stronger than that of hot water immersion. Asphalt mixtures performance is related with its gradation and percent air voids. Asphalt mixtures with different gradation are different in their percent air voids, suitable gradation can form framework and filling action obviously, so to yield mixture with suitable percent air voids and good water stability.


Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3339
Author(s):  
Fuyu Wang ◽  
Xingyuan Qin ◽  
Weichen Pang ◽  
Wensheng Wang

In order to ensure smooth traffic and driving safety, deicing salt or snow melting agents are usually adopted to solve the problem of traffic jams and prevent pavement surfaces from freezing. The objective of this present study is to investigate the performance deterioration evaluation of asphalt mixture under the chloride salt erosion environment. Five chloride salt solution concentrations were designed and the uniaxial static compression creep test, low-temperature IDT test, freeze-thaw splitting test, and freeze-thaw cycle test were carried out for asphalt mixtures (AC-16) soaked in chloride salt solution. Results showed that with the increase in chloride salt solution concentration, the high-temperature stability, low-temperature crack resistance, and water stability of the asphalt mixture decreases. Moreover, the high-temperature stability, low-temperature crack resistance, and water stability of the asphalt mixture show a decreasing trend under different chloride salt solution concentrations following the negative cubic polynomial function. Based on the viscoelastic analysis, chloride salt solution could reduce the ability of the asphalt mixture to resist instantaneous elastic deformation and permanent deformation, and this influence will become more obvious with the increase in chloride salt solution concentration. In addition, the salt freeze-thaw cycle test indicated that in the early stage of freeze-thaw cycles, the splitting tensile strength of the asphalt mixture decreases rapidly, then tends to be flat, and then decreases rapidly. This study explores the performance damage law of asphalt mixture under salt corrosion, and the analysis results of this study could provide some references for the chloride salt dosage in the snow melting project while spreading deicing salt.


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