Behavior of Multilayer Composite Ferrocement Slabs with Intermediate Rubberized Cement Mortar Layer

Abstract

Laboratory investigation was undertaken to study the behavior of multilayer composite ferrocement slabs. The slabs include two ferrocement layers with an intermediate rubberized cement mortar layer. The aim of this investigation is to find out the effect of an intermediate layer rubberized cement mortar (RCM) on the behavior of multilayer ferrocement slabs subject to static and dynamic loads. Different rubber ratios, different thickness of RCM layer, and shear connectors to connect the upper and lower reinforcement layers were used. The specimens were cast in 500 × 500 mm, with an overall thickness not exceeding 50 mm. Compressive strength, modulus of rupture, and impact resistance were also tested for RCM cubes, prisms, and cylindrical cement mortar specimens to illustrate mechanical properties for using cement mortar. The increase in the RCM layer thickness, with an increase in the crumb rubber ratio, and using shear connectors; it increases impact energy to cause first a crack and then full perforation. Static test results show that thicker RCM layers reduce yield load and slab stiffness at yield, but using shear connectors increases yield load and slab stiffness. The results show that the RCM layer enhances the impact resistance of the ferrocement composite slab. The results also show the effect of the shear connector is small in static and dynamic loads: that are using a RCM with the thickness 0.4 of the total thickness of the slab; or those using a rubber ratio that is more than or equal to 50 % in the RCM layer.