2011 Volume 9 Issue 1 Pages 73-88
The shear capacity and post-peak ductility of reinforced high-strength concrete (HSC) beams, which are greatly affected by both autogenous shrinkage and a notable reduction in shear transfer along HSC crack planes, are simulated using nonlinear finite element (FE) analysis. The volumetric change caused by autogenous shrinkage is incorporated into the analysis by introducing an effective shrinkage strain related to the initial stress that develops in the reinforcement. The computed capacity, loading/unloading stiffness, crack pattern, and mode of failure replicate data obtained from systematic experiments. Approximately 50% of the plain concrete early-age shrinkage is observed to be consistent with self-induced stresses in structural concrete. The impact of autogenous shrinkage is further emphasized in assessing shear performance together with reduced crack shear transfer. Shrinkage changes the stress transfer path and may also alter the failure mode. The multi-directional fixed crack approach is verified as a reliable structural concrete model in the case of high autogenous shrinkage as well.