A numerical and experimental investigation about tensile fracture in epoxy composite grout under thermo-mechanical load

Grouts are designed to provide high load-bearing capability and chemical/material compatibility in building structures' crevices, cracks, and gaps. Much research has recently been conducted concerning replacing conventional cementitious grout with polymer-based materials. The present study investigates the fracture behavior of epoxy composite grout under flexural loads and different temperatures. The flexural fracture will be the primary fracture mechanism considered in this study. The XFEM, combined with experimentation, will be used to study the influence of thermo-mechanical flexural load on the fracture behavior of epoxy grout. The XFEM method simulates deformation, stresses, strains, and cracking behavior without needing re-meshing and any equation inputs. The numerical simulation is carried out for the epoxy and the cementitious samples at 25? and 65?. Experiments are performed for the benchmark flexural problem, and its results are further validated by comparing them with the XFEM simulation. The flexural strength of epoxy grout is much higher than that of the cementitious one at 25?. Significant microcracking in cementitious grouts is observed, further decreasing its capacity to withstand high loads. The strength of the epoxy grout decreases with increasing temperature. The presence of voids increases with temperature, weakening the epoxy material structure under high temperatures. Selecting a more compatible filler material type, shape, and size can enhance the fracture toughness of epoxy composite grout.