摘要: |
采用分子动力学模拟技术模拟不同温度条件下环氧树脂(epoxy)/水化硅酸钙(C-S-H)界面的脱黏行为,研究了热环境对epoxy/C-S-H界面黏结性能的影响,从纳观尺度评价了其界面热敏感性.结果表明:随着温度的升高,epoxy/C-S-H界面的力学性能下降;在热环境下,epoxy在C-S-H表面附近密度降低、稳定性减弱,阻碍了epoxy与C-S-H之间的应力传递;随着温度的升高,epoxy与C-S-H之间的离子键合作用、氢键作用减弱,界面相互作用能下降.研究结果从纳观角度揭示了热环境下epoxy/C-S-H界面黏结弱化的内在机理,为FRP加固混凝土技术的优化设计和可持续发展提供了理论依据. |
关键词: 分子动力学 热环境 环氧树脂 水化硅酸钙 力学性能 温度条件 |
DOI:10.3969/j.issn.1007-9629.2022.10.013 |
分类号:TU528.01 |
基金项目:国家自然科学基金资助项目(U1806225,U2006224,51978352);山东省自然科学基金资助项目(ZR2020JQ25) |
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Molecular Dynamics Simulation of Temperature-Influenced Epoxy/ C-S-H Interfacial Bonding Properties |
YANG Qingrui, JIN Zuquan, WANG Pan, HOU Dongshuai
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School of Civil Engineering, Qingdao University of Technology, Qingdao 266033, China
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Abstract: |
The effect of thermal environment on the bonding performance of epoxy/calcium silicate hydrate (C-S-H) interface was investigated by molecular dynamics simulation technique. By simulating the de-bonding behaviors of the epoxy/C-S-H interface under different temperature conditions, the thermal sensitivity of the interface was evaluated on the nano-scale. The results show that mechanical properties of the epoxy/C-S-H interface decrease with increasing temperature. In the thermal environment, epoxy molecules near the C-S-H surface become less dense and less stable, and the stress transfer between epoxy and C-S-H is hindered. Meanwhile, the ionic bonding and hydrogen bonding interactions between epoxy and C-S-H are weakened, and the interfacial interaction energy is reduced as the temperature increases. This study reveals the micro-mechanism of bonding degradation at the epoxy/C-S-H interface in the thermal environment, provides a theoretical basis for the optimal design and sustainable development of FRP-reinforced concrete technology. |
Key words: molecular dynamics thermal environment epoxy C-S-H mechanical property temperature condition |