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³¤°²´óѧѧ±¨£¨×ÔÈ»¿Æѧ°æ£©[ISSN:1006-6977/CN:61-1281/TN]

Issue:

2021Äê4ÆÚ

Page:

1-10

Research Field:

µÀ·¹¤³Ì

Publishing date:

Info

Title:

Improvement of fatigue performance of bridge deck concrete byª¤waterborne epoxy resin in hot and humid regions

Author(s):

GUO Yinª²chuan;  CHOU Tao;  SHEN Aiª²qin;  ZHANG Chong;  YAO Chao; ª¤WEI Xin;  ZHOU Xiaoª²han

£¨Key Laboratory of Highway Engineering in Special Region of Ministry of Education,ª¤Chang¬ðan University, Xi¬ðan 710064, Shaanxi, China£©

Keywords:

road engineering;  waterborne epoxy resin;  hot and humid region;  fatigue performance;  microstructure;  bridge deck concrete

PACS:

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DOI:

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Abstract:

In order to solve the problem of insufficient flexural tensile strength and fatigue resistance of bridge deck concrete in hot and humid regions, the slurry was tested for heat of hydration and the influence of waterborne epoxy resin ¡¼HJ¡½content on the hydration process of cement was analyzed. Then the working environment of bridge deck concrete in hot and humid regions was simulated indoors, flexural tensile strength test and fatigue test were designed, the influence of waterborne epoxy resin content on flexural tensile strength and fatigue performance of bridge deck concrete were studied, and its fatigue life was fitted with ª«Sª²Nª« curve to study the relationship between stress level ª«Sª« and fatigue life ª«Nª«. Moreover, scanning electron microscope (SEM) was used to observe the changes of internal structure of the slurry and the microscopic morphology of the interfacial transition zone of the bridge deck concrete, and the fatigue performance of the waterborne epoxy resin modified bridge deck concrete was analyzed from a microscopic point of view. The results show that waterborne epoxy resin can reduce the heat release rate and total heat release of slurry hydration, and play a role in delaying cement hydration, which is beneficial to avoid early cracking of concrete due to excessive heat of hydration.The flexural tensile strength and fatigue life of bridge deck concrete are obviously improved by waterborne epoxy resin. When the content (mass fraction, the same below) of waterborne epoxy resin is 3%, the improvement effect is the most obvious. The 7 d flexural tensile strength is 20.4% higher than that of ordinary concrete, and the fatigue life is also increased by 1.7 times under the stress level of 0.75. The ª«ª©Sª²Nªªª« curve equation can well predict the fatigue life distribution of the waterborne epoxy resin to improve the bridge deck concrete under different stress levels.Then the waterborne epoxy resin modified bridge deck concrete is distributed with irregularly shaped polymer membranes, which form a dense network composite structure with the cement stone, so that the cohesiveness and water retention of the bridge deck concrete are increased, the concrete pore structure is refined and make the interfacial transition zone of concrete more compact and dense, which is conducive to improve the fatigue performance of bridge deck concrete. 3 tabs, 8 figs, 27 refs.

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Last Update: 2021-08-12