Discrete Element Modelling of Powder-compacted C-S-H Matrix

The usage of supplementary cementitious materials often alters the chemical composition of the main binding phase in modern concrete, i.e., C-S-H. The consequent influence on the mechanical properties is not completely clear, due to the lack of study on the inter-particle interaction of C-S-H. Recent papers published by the authors have provided experimental evidence, and in this work, a subsequent numerical study based on discrete element method (DEM) is provided. Models of compacted C-S-H were established with various surface interaction parameters between particles, e.g., surface energy and friction coefficient, and subjected to simulated triaxial load. The results revealed that increased surface energy and friction coefficient enhance the stiffness of C-S-H and densifies its microstructure. The work may inspire methods to design stronger cementitious composite materials.