steel fiber recycled concrete;  compressive strength;  size effects;  Aggregate pretreatment method

Taking the volume rate of steel fiber, steel fiber type, treatment method of recycled coarse aggregate and specimen size as parameters, the influence of steel fiber on the compressive performance of recycled concrete was discussed by comparing it with steel fiber natural concrete. The test results show that the compressive strength of steel fiber recycled concrete is slightly lower than that of steel fiber natural concrete, and the addition of steel fiber can improve the compressive strength of recycled concrete to a certain extent, and the size effect coefficient of the cubic compressive strength of steel fiber recycled concrete is not significantly different from that of steel fiber natural concrete. According to the statistical analysis of the test data, the influence coefficient of milled steel fiber (MF) on the compressive strength of natural concrete is 0.25, and the influence coefficient on the compressive strength of pre-wet water recycled concrete is 0.35, and the reinforcement effect of steel fiber on recycled concrete is better than that of natural concrete.