MECHANICAL PROPERTIES OF STEEL-POLYPROPYLENE HYBRID FIBER REINFORCED CONCRETE IN BUILDING STRUCTURE

This study mainly analyzed the effect of steel fiber (SF) mixed with polypropylene fiber (PF) on the performance optimization of concrete. Firstly, the steel fiber reinforced concrete (SFRC), polypropylene fiber reinforced concrete (PFRC) and steel-polypropylene hybrid fiber reinforced concrete (SP-HFRC) specimens were designed. Then, the slump experiment, compressive strength experiment, and tensile strength experiment were carried out. The results demonstrated that the increase of fibers reduced the slump, and the influence of PF on the slump was the largest, followed by SF and SP; when the content of SF was 1% and the content of PF was 0.1%, the compressive strength and tensile strength of the concrete were 73.16 MPa and 6.33 MPa, which was superior to the concrete mixed with single fiber. In the perspective of the seismic performance, the ultimate load of the SP-HFRC specimen was 6.25% higher than that of the plain concrete (PC) specimen, and its energy consumption was 126% higher than the PC specimen. The experimental results demonstrate that SP-HFRC has a superiority in mechanical property and can be further promoted and applied in building structure.