Fracture properties of high performance concrete containing silica fume

Abstract

A parametric experimental study has been conducted to investigate the effect of silica fume on the fracture properties of high performance concrete (HPC), with five silica fume contents (1.5%, 3%, 6%, 9% and 12%) used. The results indicate that the addition of silica fume has greatly improved the fracture parameters of HPC, such as fracture toughness, fracture energy, effective crack length, the maximum mid-span deflection, the critical crack opening displacement and the maximum crack opening displacement of concrete. The fracture parameters of HPC containing silica fume are increasing gradually with the increase of silica fume content when the silica fume content increases from 0% to 3%, while, the fracture parameters begin to decrease after the silica fume content increases beyond 3%. However, the values of the fracture parameters of HPC with the silica fume content below 12% are still higher than that of the concrete without silica fume. It seems a small content of silica fume has an advantage of improvement of the fracture properties of HPC, while an overlarge silica fume content may adversely affect the fracture properties of HPC.