Finite Element Analysis on Cracking Resistances of Recycled Aggregate Concrete Beams with Hybrid Fibers

In order to improve the mechanical properties and cracking resistances of recycled aggregate concrete, the influences of the volume incorporation rates of polypropylene fibers and steel fibers on the hybrid fiber recycled aggregate concrete beams are analyzed by finite element. The results show that: Compared with the ordinary RAC beams, the cracking load, the mid span deflection and the maximum compressive stress of HFRAC beams are larger under the initial cracking state. The yield load and maximum compressive stress of HFRAC beams vary little, and the mid span deflection increases or decreases under the yield state. HFRAC beams have greater stiffness and better ductility. Through theoretical calculation and finite element analysis, the formula for calculating the cracking moment of HFRAC beams is derived. (paper)