Flexural properties of steel fiber types and reinforcement ratio for high-strength recycled concrete beams

Abstract

This article took fly ash and silica fume as cementing materials to replace part of cement and took recycled coarse aggregate to replace part of gravel to mix plain concrete and studied the flexural properties of the beams with high-strength steel fiber–recycled concrete by changing the types of steel fiber and reinforcement ratio. The results showed that fly ash and silica fume could improve strength and flexural capacity of the recycled concrete beam by filling micro-cracks of recycled coarse aggregate and reduce the development speed of deflection and crack width of the test beam. Steel fibers could significantly slow the development of deflection and crack width of the beams with high-strength recycled concrete, and the difference in end-structure could increase the flexural capacity of the beams in varying degrees. The article put forward theory of improving the bearing capacity of the beam with three kinds of steel fibers by introducing the influence factor of steel fiber end-structure.