Flexural Crack Widths in Concrete Girders with High-Strength Reinforcement

Abstract

The introduction of steel reinforcing bars having yield strengths exceeding 517 MPa (75 ksi) and often approaching 827 MPa (120 ksi) may allow for significant economies to be realized, particularly when used in conjunction with high-strength concrete. One implication of the adoption of higher-strength reinforcing steel is that reinforcing bar stresses (and therefore strains and consequently crack widths) at service load levels are expected to be greater than when conventional bars [having a yield of 414 MPa (60 ksi)] are used. A study of flexural crack widths of beams reinforced with high-strength ASTM A1035 reinforcing steel is presented. Discussion focuses on the behavior at loads corresponding to longitudinal reinforcing bar stresses of 248, 414, and 496 MPa (36, 60, and 72 ksi), representing service load levels (i.e., 0.6