DAMAGE ACCUMULATION IN CONCRETE WITH AND WITHOUT FIBER REINFORCEMENT

Although concrete is known to deteriorate both in strength and stiffne ss when subjected to large numbers of load applications, especially wh en stress reversals are involved, relatively little is known about its fatigue behavior and, specifically, damage accumulation in the low-cy cle fatigue range. Herein, the results of an experimental investigatio n are reported, whose objective was measuring the energy-dissipation c apacity of concrete with and without fiber reinforcement under uniaxia l stress cycles. This test program is the first phase of a major inves tigation currently underway at Columbia University to establish a data base that can be used to develop damage prediction tools and facilitat e low-cycle fatigue analysis of concrete and concrete members subjecte d to arbitrary load histories. A new energy-based damage index is prop osed, which is well suited for quantifying concrete's residual strengt h and predicting its remaining life.