温度影响epoxy/C‑S‑H界面黏结性能的分子动力学模拟

Molecular Dynamics Simulation of Temperature-Influenced Epoxy/C-S-H Interfacial Bonding Properties

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.

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.