Numerical Simulation on Shear Capacity and Post-Peak Ductility of Reinforced High-Strength Concrete Coupled with Autogenous Shrinkage

Esayas Gebreyouhannes and Koichi Maekawa

Journal of Advanced Concrete Technology, 9(1) 73-88, 2011

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.

In the paper the authors discuss the influence of autogenous shrinkage of concrete on shear response of RC beams made of high strength concrete. The numerical analysis is performed and the results are compared with test results. It is concluded that autogenous shrinkage of concrete can strongly influence the shear resistance of RC beams. The structure of the paper is fine and also language is clear. (Reviewer B)