Mechanical properties of fully recycled coarse aggregate concrete with polypropylene fiber

Incorporating polypropylene fiber as an additive material into the mixture can effectively improve the mechanical properties of concrete. In this paper, in order to investigate the mechanical properties of fully recycled coarse aggregate (FRCA) concrete with PP fiber, four groups of specimens with different volume ratio of PP fiber were designed and manufactured to conduct experiments of uniaxial compression and bending respectively. Based on the test results, the influence of volume ratio of PP fiber on the compressive and flexural mechanical properties of FRCA concrete were analyzed. The results showed that the integrity of compression specimens with PP fiber was better after failure and the flexural failure of the specimens without fiber or with PP fiber was brittle after the peak value. Moreover, with the increase of volume ratio of PP fiber, the slump of specimens presented a downward trend, the cube compressive strength increased continuously, and the cylinder compressive strength first decreased and then increased. Besides, with the increase of volume ratio of PP fiber, the static pressure elastic modulus increased as a whole, and the flexural strength increased.