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

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.

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.