Effect of Steel Fibers and GFRP Sheet on the Behavior of Lightweight Concrete Specimens Using Waste Lightweight Sand Bricks

Abstract

High performance traditional and optimized lightweight fibrous concrete was investigated by using steel fibers and glass fiber reinforced polymer (GFRP) sheet, double action of Fibers. Basically, fibers could controlled the cracking of concrete, crack propagation and crack width. However, using fibers capable of enhancing failure mode of concrete to semi- ductile or ductile mode. Experimental work was consist of two phases, the first phase was focused on cast traditional fibrous concrete specimens in addition to control specimens to compare obtained results. These specimens were cubes, cylinders and prisms, which were tested after seven, fourteen and twenty eight days. Three percentages of round crimped (corrugated) steel fibers (0.5%, 1% and 1.5%) were used to get the optimum percentage. The second phase was concerned with cast lightweight concrete specimens by using the obtained optimum percentage of steel fibers. Specimens were cast by using waste lightweight sand bricks as an coarse aggregate (replacement percentage 50% of actual weight). The effect of strengthening with external GFRP sheet was studied for traditional and lightweight concrete specimens. The results confirmed that, steel fibers and GFRP sheet (external strengthening) increased the studied mechanical properties with competitive values in comparison to traditional concrete.