Steel-ferrocement sandwich plates under hard lateral impact

An experimental program was conducted to study the behavior of steel-cementitious composite sandwich plates under low velocity impact. Initiation of the punching mode of failure was examined adopting a specially designed frame that minimized the bending of the specimen. A 40 kg drop hammer, with a hemispherical head, under free fall from a drop height of 4 meters, was used to create the impact. A set of 300mm x 300mm square plates was used as test specimens and were subjected to lateral impact at their center. The results showed large permanent deformations in the steel cover plates but no fracture. Middle plates of normal and high strength concrete cracked into pieces under this kind of impact. Introduction of a ferrocement or SIFCON layer to the middle plate reduced the steel strains and also prevented disintegration of the middle plate. Use of a ferrocement or SIFCON middle plate further reduced the steel strains and the dent depths.