Stability of Fracturing Process in RC Beams

Abstract

A reinforced concrete beam section with a through‐thickness edge crack in the stretched part is considered. The eccentric axial force transmitted by the reinforcement to the concrete beam element, is estimated by means of a rotation congruence condition able to provide this statically undetermined reaction. In the field of linear elastic fracture mechanics, such a force increases linearly by increasing the external bending moment, until the limit force of yielding or slippage is reached. From this point on a perfectly plastic behavior of the reinforcement is considered. Once the bending moment of steel plastic flow is exceeded, the cracked beam segment presents a linear‐hardening behavior, until the concrete fracture occurs. It is shown how the stability of the process of concrete fracture and steel plastic flow depends on the mechanical and geometrical (scale included) properties of the beam cross section.