Experimental investigation of the cyclic behavior of full-scale beam-column connections using high-strength self-consolidating concrete with and without fiber

Abstract

This study investigates the seismic performance of self-consolidating concrete (SCC) and self-consolidating fiber-reinforced concrete (SCFRC) in full-scale beam-column joints subjected to cyclic loading. The experimental program involved applying reverse cyclic loads to evaluate critical structural parameters, including crack initiation, propagation, load-bearing capacity, energy dissipation, and ductility. The results revealed that while both specimens exhibited similar initial cracking patterns, the SCFRC specimen significantly outperformed the SCC specimen in terms of energy dissipation (35% higher at larger drift levels), maximum drift capacity (6% vs 4%), and crack resistance (first crack at 0.35% drift for SCFRC compared to 0.25% for SCC). The SCFRC specimen also required 55.6% of its ultimate load to achieve a drift ratio of 1%, compared to 59.5% for the SCC specimen, reflecting its enhanced deformation efficiency. Additionally, the SCFRC specimen maintained higher residual strength and delayed failure due to the effective distribution of stresses by the steel fibers. In contrast, the SCC specimen showed brittle behavior, characterized by rapid strength degradation and extensive cracking. Evaluation against the ACI-T1.1 acceptance criteria demonstrated that the SCFRC specimen exceeded the seismic performance requirements, offering greater resilience and ductility in comparison to the SCC specimen. These findings highlight the potential of SCFRC as a superior alternative to SCC in seismic design, reducing the need for extensive transverse reinforcement while enhancing the overall energy dissipation capacity of beam-column joints.