钢筋再生混凝土梁徐变性能试验研究

为揭示钢筋再生混凝土梁的徐变性能,通过三种持荷水平下9根钢筋再生混凝土梁试件的徐变(徐变应变与徐变挠度)对比试验,分析了钢筋再生混凝土梁徐变与时间的相关关系,研究了加荷幅值、初始变形(初始应变、初始挠度)等因素对钢筋再生混凝土梁徐变性能的影响规律,揭示了钢筋再生混凝土梁的徐变机理。研究结果表明:在45%极限荷载水平的持续作用下,钢筋再生混凝土梁总徐变挠度值为初始挠度值的62%左右,并且在前期发展较快,7d发展至总徐变挠度值的64%左右,后期变缓;钢筋再生混凝土梁徐变随着施加荷载幅值、初始变形的升高而有所增加。经历徐变过程后的钢筋再生混凝土梁,其承载性能有所下降,变化趋势为总徐变值越大,降低的幅度也越大。

Experimental Investigation on Creep Behavior of Reinforced Recycled Concrete Beam

To reveal the creep behavior of reinforced recycled concrete beam, creep (creep strain and creep deflection) comparative experiments for 9 reinforced recycled concrete beam specimens under 3 loading levels were carried out. The correlation between creep of reinforced recycled concrete beam and time was analyzed; the influence of loading amplitude and initial deformation (initial strain and initial deflection) on the creep behavior of reinforced recycled concrete beam was investigated; the creep mechanism of reinforced recycled concrete beam was revealed. Experimental results manifest that the total creep deflection is about 62% of initial deflection when beam specimen is subjected to a constant load level equivalent of 45% of ultimate load. Creep deflection increases faster in the early period of experiment. In 7 days, it has reached 64% of ultimate creep deflection value of the beam specimen; then the increase slows down. Creep strain and creep deflection increase with the increases of loading amplitude and initial deformation. Load bearing capacity of beam specimen decreases after experiencing creep, the decrease amplitude increases with the increases of the total creep strain and the total creep deflection.