再生混凝土基本力学性能研究(Ⅱ)

Study on Mechanical Properties of Recycled Aggregate Concrete(Ⅱ)

在单轴受压性能研究的基础上,进一步研究了再生混凝土的单轴抗拉强度、劈裂抗拉强度以及两者之间的关系,抗折强度,断裂能,与钢筋的粘结强度,热膨胀系数和高温后残余抗压强度.试验结果表明,再生混凝土的单轴抗拉强度、劈裂抗拉强度、抗折强度、断裂能及其与钢筋的粘结强度均随其抗压强度的增加而增加;普通混凝土单轴抗拉强度、劈裂抗拉强度及其与钢筋间的粘结强度计算公式也适用于再生混凝土,但普通混凝土抗折强度和断裂能计算公式用于再生混凝土则偏于不安全;再生混凝土的热膨胀系数约为1×10-5K-1,与普通混凝土差别不大;再生混凝土高温后残余抗压强度的变化规律与轻骨料混凝土类似.

Based on the study on the behaviour of recycled aggregate concrete under uniaxial compression, this paper deals with the following other mechanical properties： the uniaxial tensile strength, the splitting tensile strength and the correlationships between them, the flexural strength, the fracture energy and the bond strength between steel reinforcement and recycle aggregate concrete as well as the thermal expansion coefficient and the residual compressive strength after high temperature. It was found that the uniaxial tensile strength, the splitting tensile strength, the flexural strength, the fracture energy and the bond strength all increase with the increase of the cube compressive strength of recycled aggregate concrete. The formulations for the uniaxial tensile strength and the splitting tensile strength as well as the bond strength of normal concrete are also suitable for recycled aggregate concrete. However, the formulations for the flexural strength and fracture energy for normal concrete tend to be unsafe for recycled aggregate concrete. The thermal expansion coefficient of recycled aggregate concrete is about 1 × 10^-5 K^-1 , which is the same as normal concrete. The residual compressive strengths after high temperature for recycled aggregate concrete are somewhat similar to that of light aggregate concrete.