Determination of Fracture Parameters of Seawater Sea Sand Concrete Based on Maximum Fracture Load

Abstract

Seawater sea sand concrete (SSC) can be applied in islands far away from the mainland. It is essential to clarify the fracture behavior of SSC which is related to the durability under the ocean environment. Thus, the present study is primarily concerned with the determination of fracture parameters of SSC. Ordinary concrete (OC) mixed by freshwater and river sand is introduced for reference. Based on the improved boundary effect model, the size-independent tensile strength and fracture toughness are determined by using the experimental maximum fracture loads of three-point-bending concrete beams. The resulting tensile strength is adopted to replace the maximum tensile stress at the fictitious crack-tip in the maximum fracture load model and the former proves to be the latter. The maximum fracture load related to the local fracture energy at the crack-tip region is then predicted. The size-independent fracture energy is given by the comparison between the analytical and experimental maximum fracture loads. The local fracture energy distributions in the SSC and OC are similar to each other. But the tensile strengths of SSC are higher than those of OC. The fracture toughness and fracture energy increase with the increasing of maximum aggregate size for SSC.