Flexural properties of ultra high performance concrete reinforced with steel wire mesh or fiber mesh

To study the influence of steel wire mesh on the bending properties of ultra-high performance concrete (UHPC) slabs, a bending test of simply supported two-way slabs with four sides was carried out. The chopped fibers in UHPC ware: Steel fiber and steel fiber were mixed with polyvinyl alcohol fiber, glass fiber and basalt fiber, respectively. The research parameters were: Number of layers of wire mesh and glass fiber mesh, pore size and proportion of blended fibers. The results show that when UHPC is single-doped with 1.5vol% steel fiber, the ultimate bearing capacity and energy absorption at 25 mm deflection of UHPC slabs with 3 layers and 4 layers are increased by 14.9%, 32.3% and 14.1%, 25.2%, respectively compared with UHPC slabs with 2 layers of steel wire mesh. When the total volume fraction of hybrid fibers is 1.5vol% and the steel wire mesh is 2 layers, the blending of 1.0vol% steel fiber and 0.5vol% polyvinyl alcohol fiber has better reinforcing and toughening effect on UHPC slabs, and the UHPC slab mixed with 0.5vol% steel fiber and 1.0vol% glass fiber or basalt fiber has a stronger ability to maintain load after peak load than 1.0vol% polyvinyl alcohol fiber, namely the mixing of steel fiber with higher modulus of elasticity non-metallic fiber is advantageous to increase the post-cracking bearing capacity. Compared with glass fiber mesh, UHPC slabs with steel mesh have better ductility after peak load. A method for evaluating the flexibility of UHPC slabs with peak load deflection as initial cracking parameter was proposed, which can characterize the contribution of mesh and fibers to the post-crack toughness of UHPC slabs. Based on the concept of effective utilization of mesh, the theoretical value is in good agreement with the experimental value by calculating the bending capacity. © 2022, Editorial Office of Acta Materiae Compositae Sinica. All right reserved.