Bending capacities of glass fibre reinforced plastic composite slab

To compensate for the weak points of steel structures, a new composite floor system reinforced by glass fibre reinforced plastic (GFRP) plate is proposed. The newly developed GFRP composite system consists of an asymmetric steel beam with web openings, hollow core balls, steel deck, rebar, concrete and GFRP plate. To verify the flexural performance of this system, a series of tests were conducted. Test results showed that the bending resistance, stiffness and flexural rigidity EI of the proposed system improved by 11, 14 and 10% respectively compared to specimen without GFRP. The bearing strength of concrete in the web openings and bond strength between the steel beam and concrete slab were enough to resist longitudinal shear force. Hence, full interactive composite behaviour was provided without any other shear connectors. The GFRP plate was attached at the bottom of the steel beam until the test was finished, and there was no fracture in the plate. When calculating the resistance of the proposed system according to the plastic stress distribution method of American Institute of Steel Construction specifications, it is recommended that the concrete compression zone in the level of the hollow core balls be omitted for more conservative and convenient design.