地聚合物凝胶体系中N-A-S-H和C-A-S-H结构的分子模拟

Molecular Simulation of N-A-S-H and C-A-S-H in Geopolymer Cementitious System

钙元素对地聚合物凝胶结构的形成影响显著,根据含钙量的不同可分为高钙体系(C-A-S-H)和无钙体系(N-A-S-H).基于Materials Studio软件,用Amorphous Cell(AC)模块构建了N-A-S-H和C-A-S-H凝胶结构模型.在Universal力场下,对2个凝胶结构模型的稳定性、动力学轨迹、微观表征及弹性模量进行了分子动力学模拟.结果表明,构建的N-A-S-H和C-A-S-H凝胶结构模拟值与试验值吻合较好.由于钙元素的存在,无定形态体系出现了向晶体转变的特征,并对地聚合物的力学性能产生正向增益.

Calcium has a significant effect on the formation of geopolymer cementitious structure.According to the content of calcium,the cementitious structure can be divided into high calcium system(C-A-S-H)and calcium-free system(N-A-S-H).The structure models of N-A-S-H and C-A-S-H were established by using Amorphous Cell(AC)module in the Materials Studio software.Universal force field was introduced into simulation processing,the stability,dynamic trajectory,microstructure characterization and elastic modulus of N-A-S-H and C-A-S-H structure models were studied.The results show that the simulated values of N-A-S-H and C-A-S-H structure models are well matched with the experimental values.Due to the effect of calcium,the amorphous system of geopolymer transform to crystal system,and the mechanical property of geopolymer is improved significantly.