Local Bond Stress-Slip Behavior of Reinforcing Bars Embedded in Plain and Fiber Concrete

This study summarizes the results of an experiment on the bond and slip characteristics of reinforcing bars embedded in fiber reinforced concrete (FRC). More than 100 concentric pullout specimens were tested and the effect of several parameters on the local bond stress-slip response of reinforcing bars was studied. Parameters included diameter of reinforcing bar; mode of bond failure; concrete splitting area surrounding the reinforcing bar; and type, volume fraction, and aspect ratio of fibers. The authors discuss the test results and present a simple analytical model describing the local bond stress-slip relationship for reinforcing bars embedded in plain and FRC and subjected to monotonically increasing load in tension. The model accounts for most of the important parameters that affect the local bond stress-slip response as observed in the experiment.