Research on Mechanical Property and Impact Performance of Composite Rubber Hybrid Fiber Concrete

To explore the effects of different particle sizes of rubber particles, mixed basalt fibers and polypropylene fibers on the mechanical property and impact performance of concrete. The combined waste tire rubber particles with various particle sizes were proposed. Then the combination of rubber content of various particle sizes, the volume content of different basalt and polypropylene fibers seemed as influence factors, and nine kinds of composite rubber hybrid fiber concrete (CRFC) were designed by the orthogonal test method. Compressive, splitting tensile, dynamic compressive and impermeability tests were carried out. The impacts of the three influence factors on the CRFC test index were obtained according to the range and variance analysis of the test data, meanwhile, the energy conversion in the process of dynamic compression was used. All that aimed to reveal the influence mechanism of three influencing factors on the mechanical, impact and impermeability properties of CRFC. The results showed that the increase in the particle size of the rubber weaken the uniform dispersion ability of the rubber particles in the matrix, the rate of energy absorption/dissipation, the energy storage limit, the failure energy and the transmission energy ratio of the CRFC and the ultimate load capacity of the concrete. However, the adhesion between the rubber particles and the matrix, the ability to prevent crack propagation, the ratio of reflected energy, the accumulated elastic energy, and the ductility of concrete all improved with the particle size of the rubber. Although there are different physical properties for the basalt fiber and polypropylene fiber, the good rigidity and ductility can be found in the CRFC impact test, and the appropriate amount of fiber content can mostly exert the synergistic effect of hybrid fiber. Finally, the static compression and dynamic impact damage models of CRFC are established on basis of the statistical damage theory. That can provide reference for engineering application of CRFC.