コンクリートの曲げ破壊挙動の寸法依存性に関する破壊力学的考察

Abstract

In this study, bending tests of plain and steel fiber reinforced concrete beams were carried out for examining the size effect of the fracture behavior of concrete and the fracture mechanics parameter. Following results were obtained in this study : 1) The flexural strength of plain and steel fiber reinforced concrete decreases with increasing the size of specimen and the relationship between strength and size of specimen can be explained by a stochastic theory for 2 states and 1 process problem. 2) The normalized load (P) - displacement (d) relation of plain concrete in the strain softening region becomes ductile with increasing the size of specimen, but that of steel fiber reinforced concrete becomes brittle because the crack arrest effect due to the steel fiber decreases with increasing the size of specimen. 3) The fracture energy estimated by using a RILEM's method and an inverse analysis method increases with increasing the size of specimen.