摘   要：对钢纤维掺量为0、1.5%、 2.0%、 2.5%、 3.0%的圆柱体混凝土试件进行了等应变增量循环加卸荷试验， 应变速率为10^-3/s。试验结果表明，在试验开始的四次加卸载循环中，SFC25混凝土在各再加载点处的残余应变最小，其余的四种混凝土按钢纤维掺量的增加，残余应变依次减小。随后的试验中，五种混凝土的残余应变随钢纤维含量的增加而减小，各种钢纤维混凝土的总残余应变按钢纤维含量较依次减少0.0929%、0.095%、0.0355%、0.1469%。各加卸循环中的残余应变在前四次循环中增加较快，而随后的循环试验中增加不明显，基本保持在一定的数值。整个加卸载试验过程中，五种混凝土在各次循环中的残余应变随钢纤维含量的增加而降低。

Abstract: The equidifferent strain incremental cyclic loading and unloading tests with the strain rates at 10^-3/s are taken for the cylinder concrete samples with the steel fiber content of 0%、1.5%、2.0%、2.5%、3.0%. The test results show that in the initial four cyclic loading and unloading tests, residual strains at the reloading points of steel fiber concrete of 25 grade (SFC25) are least in five kinds of concrete, and the residual strains of other four concrete are decreasd with the increase of steel fiber content. In the following tests, the residual strains of five kinds of concrete are decreased while the steel fiber content  is increased, and the total residual strains of the five kinds of steel fiber concrete are decreased in turn by 0.0929%、0.095%、0.0355%、0.1469% ,which compare with the former ones at last. The residual strains of each cycle are increased rapidly in initial four cyclic loading and unloading tests, then in the following tests, the residual strains are increased not clearly and keep at a constant value.The residual strains of five kinds of steel fiber concrete in each loading and unloading cycle are decreased as the steel fiber content are increased in the whole test process.