Shear strengthening of prestressed concrete hollow-core slabs using externally bonded carbon-fiber-reinforced polymer sheets

摘要

Precast, prestressed concrete hollow-core slabs are widely used for floor decks in office and residential buildings and in parking structures. Although they are generally designed to resist bending moments under uniformly distributed loads, in some cases, shear failure can occur at the region close to support due to a large concentrated or line load. The manufacturing process for this type of member does not allow shear reinforcement to be arranged in the slab webs during fabrication. Therefore, the web shear resistance is only provided by the concrete itself, which governs the member capacity. The objective of this study was to explore the feasibility and effectiveness of a novel shear-strengthening technique using externally bonded carbon-fiber-reinforced polymer (CFRP) composite sheets along the internal perimeter of slab voids. Both experimental tests and numerical simulations were conducted to investigate the behavior of ten full-sized prestressed concrete hollow-core slabs: eight specimens strengthened with CFRP and two control specimens. The studied parameters included the length, width, and thickness of the applied CFRP sheets and the prestressing level of the prestressed concrete hollow-core slabs. The results show that the proposed shear-strengthening technique not only considerably enhances the shear capacity of prestressed concrete hollow-core slabs but also sizably improves the ductility.