Experimental investigation of the effects of aggregate size distribution on the fracture behaviour of high strength concrete

This paper examines the influence of different aggregate size distributions on the fracture behaviour of high strength concrete. Three-point bend test was performed on 63 notched beams casted using three aggregate size distributions and two water to binder ratios. The total fracture energy, GF, and critical stress intensity factor, KIC, were used to determine the fracture characteristic of concrete. The results show that the values of GF decrease substantially with increasing coarseness of aggregate grain structure, λ. Values of KIC also decreased but demonstrated only limited dependence on λ. In contrast, reducing the total w/b ratio substantially increases the value of KIC but had no measurable effect on GF.