The combined effect of lightweight coarse aggregate and steel fibers on the mechanical properties of concrete

Abstract

The most evident properties of LWAC by which it is differentiated from normal weight concrete are its lower density and better insulating potential. The aim of this study is to examine the combined effect of lightweight coarse aggregate and steel fibers on concrete's mechanical properties. In this study, three different types of coarse aggregate (normal weight, crushed clay brick and Attapulgite) with different percentages of steel fiber (0%, 0.5%, and 1%) were used. The results show that replacing normal weight concrete with lightweight concrete leads to a decrease in unit weight, compressive strength, splitting-tensile strength and modulus of elasticity, while water absorption increases. With the increase of steel fiber ratios in the mixtures, the mechanical properties of lightweight concrete improve significantly compared with the control sample with no fiber. When 1% steel fiber is used, the splitting-tensile strength increases by about 115.6% and 55.7% and compressive strength decreases by about 7.4% and 22.2% for crushed clay brick and Attapulgite, respectively, compared with normal weight concrete.