Experimental Study on a Novel Sandwich Panel Under Repeated Impact Loads

Engineering structures may suffer repeated impacts from vehicles or falling objects during service life. Compared to traditional reinforced concrete structures, Steel-concrete-steel (SCS) sandwich composite fully uses the excellent tensile property of steel and compressive property of concrete. When subjected to impact, the steel plate can effectively prevent the impactor penetration, and the concrete core works as the energy dissipation layer, leading to excellent impact resistance of the sandwich structure. To further improve the impact performance, on the material side, the study adds rubber powder into the Ultra-Lightweight High-Ductility Cement Composite (ULHDCC) to develop the rubberized ULHDCC, i.e., RULHDCC; and on the structural side, the study utilizes hybrid shear connectors and double-layer sandwich. The study conducts an experimental program on the newly developed sandwich panels under repeated impact loads using the drop-hammer impact test machine. The failure modes, impact force responses, mid-span displacement responses, peak impact force, peak displacement and residual displacement are discussed in detail. The study also reveals the influences of the design parameters to the impact resistances of the sandwich panels, such as layer number, type of shear connector, spacing of shear connector, rubber content and impact number.