Investigation on mechanical behaviors of a new sustainable composite material for fiber-reinforced recycled aggregate concrete under compressive low-cycle loadings

Recycled aggregate concrete (RAC) has been attracting worldwide research and development interests due to its ecological and economic significance. In this investigation, the steel fiber (SF) and polypropylene fiber (PPF) were mixed into the recycled aggregate concrete (RAC) to improve the mechanical properties. Based on the cyclic compressive loading tests, the variation of the strength and deformation of fiber-reinforced recycled aggregate concrete (FRAC) was explored, and the optimum design method of fiber content for FRAC was proposed. The calculation models for fiber influence factors (FIFs) of the peak stress, peak strain, ultimate strain, and the post peak modulus were put forward, respectively. The optimum volume fractions of SF and PPF for RAC were recommended, which are 1.7% and 2.27%, respectively. This study provides technical support and a theoretical basis for the promotion of recycled aggregate concrete material and structure.

Automated summary

Recycled aggregate concrete (RAC) has gained global attention for its ecological and economic significance. This study mixed steel fiber and polypropylene fiber into RAC to improve its mechanical properties and proposed an optimum design method for fiber content in fiber-reinforced recycled aggregate concrete (FRAC).