Investigating One way Bending Behaviour of Strawboard Concrete Composite slab with Alternative Shear Connectors

Abstract

There is a growing concern about the need to integrate the use of sustainable materials in the construction industry. This has motivated research into strawboard-concrete composite floor panels which combine the structural properties of strawboard and concrete. These floor panels limit the amount of concrete used hence reducing the carbon footprint while incorporating strawboard, a material made from remains of cereals with significant mechanical properties. These composite panels utilize the compressive strength of concrete and the tensile strength of strawboard to form slabs with enhanced strength, stiffness and increased load capacity. However, due to limited information about the mechanical properties of strawboard panels, the composite panels are not commonly used. This study investigates the one way bending behaviour of strawboard-concrete composite floors with various shear connectors. The composite panels were setup with strawboard panels of dimensions of 800 x 300 x 58mm and a concrete topping of thickness 75mm. The shear connectors used include inclined and vertical screws, bolts, dowel bars and epoxy glue resin. A three point flexural test was carried out on ten composite panels and two plain strawboard panels to compare deflection and stiffness values and to determine the failure load. Test results showed that stiffness, mid span deflection and failure load vary with different shear connectors. The plain strawboard panels exhibited low stiffness, high mid span deflection values and a high failure load compared to the composite panels. Among the various connectors used in the composite panels, the bolts showed the greatest stiffness, strength and least deflection. The inclined screw connectors showed greater strength and stiffness compared to vertical screw connectors. Results from this study will provide reference for design of strawboard-concrete composite floors and beams. This study will also provide more information about the mechanical properties of strawboard panels thereby calling for an in-depth research into their use as structural members.