Experimental investigations of resilient hybrid fiber reinforced SCC beam-column subassemblies under cyclic loadings

Abstract

Fiber is not only minimizing the temperature and shrinkage cracks, but also increases the strength and toughness of the concrete. In this paper, steel fiber (SF) and areca leaf sheath (ALS) fiber have been introduced to enhance the overall performance of concrete in terms of ultimate strength, ductility, energy dissipation, and stiffness degradation. For this purpose, a one-third scaled reinforced concrete beam-column joint (RCBCJ) has been cast as the control specimen. Steel fiber reinforced concrete beam-column joints (SFRCBCJ) with volume fractions 1%, 2%, 3% and 4%; areca leaf sheath fiber reinforced concrete beam-column joints (ALSFRCBCJ) with volume fractions 1%, 2%, 3%, and 4%, and steel-areca hybrid fiber reinforced concrete beam-column joints (SAHFRCBCJ) (1:1 ratio) with volume fractions 1%, 2%, 3% and 4% have been cast. The joints were tested under cyclic loading using a large-scale actuator. It has been observed that the incorporation of SF and AL fibers has significantly enhanced the resilience and performance of joints in terms of ductility, ultimate load carrying capacity, stiffness degradation, and energy dissipation for all SFRCBCJ, ALSFRCBCJ, and SAHFRCBCJ specimens. However, the SAHFRCBCJ specimens have shown the optimum results in terms of performance and economical perspective compared to the other specimens. From the experiments, it has been observed that SFRCBCJ shows 27% higher load carrying capacity, 87% more dissipated hysteretic energy absorption capacity, 81% higher stiffness, and 41% higher ductility compared to RCBCJ subassemblies.