Experimental investigation of beam-column joints made with high-volume fly-ash concrete subjected to reversed lateral loading

Abstract

This paper presents the results of an experimental investigation carried on exterior beam-column joints made with high-volume fly-ash concrete, containing fly-ash as a 50 % replacement for cement. Six real-scale joints, two made with a conventional mix and four with fly-ash concrete, were tested under a constant axial load and reversed lateral loading, which simulates the earthquake forces. The six joints exhibited the same failure mode, which involved concrete crushing at the panel joint and minor cracks were noticed along the height of the column. The seismic characteristics, like hysteretic response, peak load displacement, ductility, stiffness degradation and energy absorption, were obtained both with the conventional and fly-ash concrete beam-column joints. The results demonstrate that the specimens made with fly-ash concrete are able to attain higher loads than the conventional specimens. The experiments show that the strength of beam-column joints made with high-volume fly-ash concrete is less at earlier stages and it gains more strength at later stages than the conventional concrete.