Crack-Width Prediction for High-Strength Concrete Fully and Partially Prestressed Beam Specimens Containing Steel Fibers

This paper describes an experimental and analytical comparison of crack widths in eight fully and seven partially prestressed high-strength concrete beam specimens containing fibers (plain concrete strength 65 MPa). The variables considered in the experimental program were the magnitude of prestress, the volume fraction of fiber ranging from 0 to 1.5%, and the location of the fibers. The analytical model proposed in this study to compute the crack width includes the effect of fiber content expressed in terms of its volume fraction and aspect ratio, magnitude of the longitudinal steel strain, and the interfacial bond stress between the concrete and steel (prestressing wires, deformed bar, and fibers). It has been found that the analytical model is able to predict the crack width satisfactorily, when compared with the measured crack width, for each of the 15 beams tested in this study, from the cracking stage up to the stage just prior to failure.