氧化石墨烯增韧水化硅铝酸钙的反应分子动力学模拟

Reactive Molecular Dynamic Simulation of Graphene Oxide Enhanced Calcium Silicat Aluminate Hydrate

水泥-辅助胶凝材料(SCM)/氧化石墨烯(GO)兼顾轻量化碳足迹以及延性增强等优点。SCM水化时释放的铝相在水化硅铝酸钙(C-A-S-H)/GO中以各种形式存在。基于反应分子动力学探究了桥接相邻硅链的铝相[Al(Q^(2)b)]与层间铝(Alinter)对于C-A-S-H/GO力学性能的影响差异。结果发现虽然Alinter含量少于Al(Q^(2)b),但在体系断裂过程中能够重分配应力,激活多层间分担荷载,触发“复苏-强化”机制进而成倍提升力学性能。通过解析Al对于界面键合网络的重组机制以及断裂过程中化学键演化,最终解释其机理。基于本研究结果,在水泥-SCM/GO制备中如何定向调控铝相所处的化学环境将成为突破延性瓶颈的关键。

Cement-supplementary cementitious materials(SCM)/graphene oxide(GO)combine a lower carbon footprint with ductility enhancement.Aluminum phase released during the SCM hydration occurs in various forms in C-A-S-H/GO.The effects of bridging Al(Q^(2)b)and interlayer Alinter on the mechanical properties of C-A-S-H/GO were investigated based on the reactive molecular dynamics.It is indicated that Alinter with less than Al(Q^(2)b)redistributes the stress during the fracture of the system,activating load sharing between the layers,and thus triggering a“recovery-reinforcement”mechanism to multiply the mechanical properties.The“recovery-reinforcement”can be explained via analyzing Al's contribution to the reorganization of the interfacial bonding network and the chemical bonding evolution during fracture.The results show that the targeted regulation of Al chemical environment in cement-SCM/GO preparation is a key issue to break the ductility bottleneck.