Experimental study on the effect of aggregate content on fracture behaviorof concrete

Effect of aggregate content on fracture behavior of concrete is studied by testing on 48 geometrically similar three-point bend concrete beams. The re sults are analyzed by using a size effect method, in which the fracture beh avior of concrete is characterized by two parameters: fracture energy G(f) and effective fracture process zone c(f). Test results showed that with inc reasing Volume fraction of aggregate in the range 45-75%: (1) the compressi ve strength of concrete decreases slightly (15%), and can be practically co nsidered to be a constant; (2) fracture energy G(f) varies within 25%, and there is not critical volume fraction which gives the maximum Gf; and (3) t he size of the fracture process zone decreases, which may be explained by t he change in coarseness of grain structures defined in terms of mosaic patt erns. (C) 2000 Elsevier Science Ltd. All rights reserved.