Investigations on strength and fracture in RC beams scaled along height or length

Abstract

The objective of the present paper is to identify experimentally and theoretically differing failure mechanisms in reinforced concrete beams subjected to four-point bending for a separate variation of the depth and length at the constant thickness. Experiments were performed on reinforced concrete beams under four-point bending. Different failure mechanisms included steel yielding, diagonal tension or shear- compression depending upon the ratio of the shear to the beam depth a/D. The shear strength of beams evidently decreased with increasing a/D-ratio. The experimental results were numerically simulated using two-dimensional finite element analyses under plane stress conditions, based on a coupled elasto-plastic- damage constitutive model for concrete that was enhanced by non-locality in the softening regime. The numerical calculation results satisfactorily captured both the experimental shear strength and failure mechanisms.