高温后型钢再生混凝土梁的受剪性能试验研究

为研究高温后型钢再生混凝土梁的受剪性能,考虑再生粗骨料取代率、温度、混凝土强度等级3个变化参数,设计了17个试件进行不同高温后的静力加载试验。通过试验测试到不同高温型钢再生混凝土梁的物理及力学性能指标,并观察了该类梁高温后的受力破坏过程及形态,获取了其极限承载力以及受力破坏全过程的荷载-挠度曲线等重要资料,并分析了各变化参数对高温型钢再生混凝土梁的初始刚度、峰值荷载、延性系数及能量耗散的力学性能指标的影响规律。研究结果表明:随着温度的升高,型钢再生混凝土梁的质量变轻、初始刚度和峰值荷载降低,延性系数、能量耗散值则先减小再增大。取代率对各力学性能指标影响不大。随着混凝土强度的增大,初始刚度和峰值荷载增大,延性系数变小,能量耗散值基本不变。

SHEAR PROPERTIES EXPERIMENT OF STEEL REINFORCED RECYCLED AGGREGATE CONCRETE BEAMS AFTER ELEVATED TEMPERATURES

To study the shear properties of steel reinforced recycled aggregate concrete beams subjected to elevated temperatures,17 specimens were designed for static load test under different elevated temperatures, and the replacement rates of recycled coarse aggregate,temperatures and concrete strength grades were considered. The physical and mechanical properties of steel reinforced recycled aggregate concrete beams after different temperatures were tested. The damage processes and patterns were observed. The load-midspan deflection curves and ultimate bearing capacities were obtained. The influence regularities of varying parameters on the initial stiffness,peak stresses,the ductility coefficients and energy dissipation of steel reinforced recycled aggregate concrete beams subjected to elevated temperatures were analyzed. The results showed that as the increase of temperatures,the masses of steel reinforced recycled aggregate concrete beams lost; initial stiffness and peak stresses decreased; the ductility coefficient and energy dissipation first decreased and then increased. As the increase of replacement ratios,mechanical properties changed a little. As the increase of concrete strength,the initial stiffness and peak stresses increased; the ductility coefficient was smaller; energy dissipation changed rarely.