A kinematics-based model for complete behaviour of RC dapped‑end connections governed by re‑entrant corner cracks

Reinforced concrete dapped-end connections, which are common in existing Gerber-beam bridges, typically feature an inclined corner crack at service loads due to the high stress concentrations in the re-entrant corner. These cracks introduce corrosion issues and increase the stresses in the dapped-end reinforcement, which in the event of further deterioration and increased loading may lead to yielding and failure of the connection. This paper proposes a kinematics-based model for the complete behaviour of such connections which predicts the opening of the cracks based on first principles: compatibility, equilibrium and constitutive relationships. The model stems from an earlier kinematics-based approach for the capacity prediction of dapped-end connections failing along re-entrant corner cracks, and extends it to describe the complete pre-peak, peak and post-peak behaviour.