Abstract:Influence of aggregate size on fracture properties of concrete was studied by means of AE technique,and three dimensional acoustic emisssion technique was applied to observe the phase of the fracture process of concrete.The results show that the fracture energy increases with increasing the maximum aggregate size.Moreover,there is a good corresponding relationship between AE counts and fracture energy.The larger the coarse aggregate size,the more remarkable deflection in the development of crack,and the wider fracture process zone is created.