非标准钢筋混凝土三点弯曲梁双K断裂特性

Double-KFracture Characteristics of Three Point Bending Beams of Non-standard Reinforced Concrete

以双K断裂理论为基础,基于标准钢筋混凝土三点弯曲梁断裂特性,推导了非标准钢筋混凝土三点弯曲梁断裂参数计算公式.开展了非标准钢筋混凝土三点弯曲梁试件断裂试验,研究了其断裂参数的变化规律.结果表明:试件荷载值随试件高度的增加而增大;而试件的亚临界扩展相对值、断裂韧度、起裂断裂韧度和失稳断裂韧度均不随试件高度的增加而变化,可认为是常数.

Fracture test of three point bending beams of non-standard reinforced concrete was carried out. The fracture characteristics of three point bending beams of non-standard reinforced concrete were studied systematically. Results indicate that the initial load and the maximum load increase with the increase of specimen height. The precritical crack propagation length relative value is independent of specimen height. Similar to the double-K fracture toughness, both the initiation fracture toughness and the unstable fracture toughness are not change with the increase of specimen height, which can be regarded as constants to three point bending beams of non-standard reinforced concrete.