Impact Behavior of Fabric-Cement Based Composites

A drop weight three point bending test machine was used to study the dynamic behavior of fabric-cement based composites. Hybrid sandwich specimens made from combinations of short fibers and fabrics were prepared by manual batch process. In addition, laminated composites were produced by the pultrusion process. The acceleration, deflection and loads were recorded to compute the strength and energy absorption. Composites made from short polypropylene and polyvinylalcohol fibers are compared with polypropylene and AR glass fabric composites. The specimens were tested in three different directions: parallel and perpendicular to the fabric length as well as through the specimen thickness (x and z directions of the specimens). The microstructure of failure surfaces were studied using optical and scanning electron microscopy (SEM) and observations were correlated with the mechanical properties of the different systems. It is demonstrated that fabrics are very promising reinforcements for cement-based elements exposed to dynamic loading. Composites reinforced with fabrics showed significantly greater impact behavior compared to those reinforced with fibers. The best behavior was reported for the pultruded composites made from PE knitted fabrics.