Shear behavior of fiber reinforced concrete beams with high fly ash content

Abstract

The shear behavior of Fiber Reinforced Concrete (FRC) beams with high Fly Ash (FA) content is investigated experimentally. Despite greater understanding of FRC shear behavior for the design of structural elements such as beams, the practicality of FRC with a high FA content has yet to be determined. Despite the fact that substantial study has been undertaken to establish the optimal usage of FA as a cement and fine aggregate replacement in concrete while investigating the shear behavior of conventional concrete, only a few studies have focused on the influence of FA in the FRC on concrete's shear behavior. The findings of shear tests performed on the FRC concrete beams of dimension 900 mm long by 80 mm wide by 120 mm high containing a high FA content up to 50 % are presented in this study. This study's principal goal is to investigate the impact of factors such as FA replacement level with fine aggregate and fiber volume on the shear behavior of concrete beams. Concrete mix with different combinations of 50 % FA by weight, as a replacement for fine aggregate, and steel fiber 1 % by volume is investigated. A four-point loading setup was used to test each of the beams. The results on FRC shear resistance capacity at failure load, as well as the effect of fiber volume and high FA content on ultimate load, have been presented and discussed. Mid-span deflection and crack patterns are also investigated during testing. The test results reveal that FRC overperforms in the presence of FA at a level of 50 % fine aggregate replacement with FA. Fibers, as expected, delayed crack formation and significantly reduced their width. As a result, it can be concluded that 50 % fine aggregate replacement with FA can be used effectively in concrete construction with no significant loss in shear strength, both in the presence and absence of steel fibers.