Experimentally validated meso-scale fracture modelling of foamed concrete

Abstract

This work presents a study of mechanical properties of foamed concrete at the meso-scale based on a combination of X-ray computed tomography (XCT) technique and a discrete lattice type fracture model. The microstructure of the foamed concrete with different densities was obtained by XCT technique and binarized as two-phase (pore/solid) materials. The parameters (e.g., porosity, pore diameter and spacing distribution) of foamed concrete air‐void structure were characterized. The virtual specimens were subjected to computational uniaxial compression, Brazilian splitting and three-point bending test to calculate strengths and elastic modulus. The mechanical properties of solid phase were derived from the recent outcome of micromechanical models. Two types of element input parameters were used to investigate the influence of the input parameters on the simulated results. The modelling results (strength value and fracture pattern) were compared with the experiments. It shows that, without further calibration, the lattice model can predict the mechanical strength and crack pattern with good accuracy. The fracture toughness KIC was derived using three-point bending strength and the average pore diameter. The results indicate that the presence of air-void structure increases the brittleness and reduces the fracture toughness of the foamed concrete.