Rupture probability of coarse aggregate on fracture surface of concrete

In this work, the fracture surface of concrete was analyzed by the digital image analysis (DIA) technique, and the rupture probability of the coarse a ggregate (RPCA) was used to represent the failure mode of the aggregate at the fracture surface. The relationships between the RPCA, the water-binder ratio (W/B), and the size and type of coarse aggregate were investigated. P reliminary results showed that: (1) RPCA increases with decreasing W/B of c oncrete. (2) RPCA of concrete with coarse aggregates having a maximum size of 16 mm is higher than that with other sizes of coarse aggregate. The infl uence of the size of coarse aggregate on the RPCA is more significant in hi gh strength concrete than in normal strength concrete. (3) With reduction o f W/B, the interfacial bond of concrete with crushed gravel improves more s ignificantly than with round gravel according to their RPCA. (4) RPCA depen ds not only on the intrinsic strength, sizer and shape but also on the reac tivity of the coarse aggregate. (C) 2000 Elsevier Science Ltd. All rights r eserved.