地聚合物凝胶体系中N-A-S-H和C-A-S-H结构的分子模拟研究

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

摘要:

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)。本文基于Materials Studio软件,运用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,对两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,所建的N-A-S-H和C-A-S-H凝胶结构模拟值与实验值吻合较好。由于钙元素的存在,无定形态的体系特征出现了向晶体转变的特征,同时对地聚合物的力学性能产生正向增益。

Abstract:

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). In present work, 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. Universe 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 structures are well matched with the experimental values. Due to the effect of calcium, the characteristics of amorphous system of geopolymer transform to crystal system, and the mechanical property of geopolymer is improved obviously.