早龄期钢纤维混凝土抗裂性能测试与计算

The test and calculation of fracture resistance property for steel fiber-reinforced concrete in early age

采用三点弯曲切口梁和楔入劈裂紧凑拉伸两种试验模型,测试早龄期阶段钢纤维混凝土材料的抗裂性能;由试验数据计算裂纹应力强度因子和断裂能等表征断裂性能参数。通过分析试验与计算数据,发现随着龄期的增长,钢纤维混凝土的承载能力和抗裂性能都不断增大,在早于7d龄期内,钢纤维与混凝土基体之间的界面作用已经比较明显,抗裂能力明显强于同阶段的普通素混凝土。

Both types of specimen, three-point bending beam with notch and wedge splitting test specimen are applied to measure the fracture-resistance properties of fiber reinforced concrete in early age. The fracture stress intensity factor and the fracture energy of the materials, two important parameters in Fracture Mechanics, are calculated based on the test data. Through the analysis of the test data, there is the conclusion that with the increase of the age, the fiber reinforced concrete has a continuously increasing capacity of loading and resistance of fracture. In the stage of the first 7 days, the interaction of steel fiber and concrete matrix is growing. The fracture-resistance properties of fiber reinforced concrete are more than those plain concrete.