Evaluation of Reinforced Concrete Dapped-End Girders Subjected to High Fatigue Loading Designed to Euro Code 2 Standard

Abstract

Reinforced concrete dapped end beams (RC-DEBs) in service suffer damage near the reentrant section under unknown loading conditions, reducing service life, particularly when recurrent loading is considered. In this investigation, a Finite Element Model (FEM) of a standard RC-DEB was used, together with a 3-dimensional concrete model and a fixed constitutive model. The girder reinforcement was designed in compliance with Eurocode 2 (EN-2) criteria for shear and deflection analysis. The level of deterioration under fatigue difficulties was determined by doing a fatigue analysis of moving and fixed pulsing loads at the midpoint and offset loading. A scaled-down experimental validation of the FEM for fixed pulsing loading was considered to better understand fatigue deterioration for practical applications. The major mode of damage observed is shear brittle failure at the beam's reentrant region. Although the moving load proved to be more damaging than the fixed pulsing load, loading at an offset of a/d of unity had an effect on the reentrant portion. The EN-2 code is nonconservative when it comes to describing the reinforcement at the reentrant section; for optimal performance, the hanger reinforcement must be properly anchored to the shear.