Effects of fiber types and volume fraction on strength of lightweight concrete containing expanded clay

Abstract

The main goal of this research is to investigate the effect of polyvinyl alcohol (PVA) fiber and steel fiber on lightweight concrete, in which lightweight aggregate was used as the coarse aggregate. The lightweight aggregate was a kind of expanded clay aggregate made using bottom ash from a thermal power plant located in South Korea. Three types of specimens, lightweight concrete without fibers (LC), lightweight concrete containing polyvinyl alcohol fiber (LCPVA), and lightweight concrete with steel fiber (LCSF) were cast with two different fiber-volume fractions (0.5 and 1.0%). Tests of their compressive strength and splitting tensile strength were performed to evaluate the effectiveness of fiber type and fiber-volume fraction in lightweight concrete at 28 days and after 90 days. The results indicated that using fibers in lightweight concrete improved both the compressive strength and splitting tensile strength. The addition of fibers in lightweight concrete showed a positive effect, and the effectiveness of PVA fiber at 28 and 90 days (regarding compressive strength and splitting tensile strength) was more pronounced than steel fiber. Overall, it can be concluded that the 1.0% PVA fiber-volume fraction showed good performance in the lightweight concrete.