Behavior of self-compacting concrete-encased steel composite dapped-end beams

This study employs H-shaped steel sections in different configurations to enhance the shear capacity and ductility of self-compacting concrete-composite dapped-end (DE) beams under flexure testing. Ten DE beams were examined: eight composite DE beams, one regular reinforced concrete (RC) beam with strong shear reinforcement at the DE, and one ordinary RC beam without shear reinforcement. The steel section-to-beam section area (AH/AC) ratio outside and/or within the DE, as well as the embedded length of the H-shaped steel section outside the DE, are the factors under test. The effects of test variables on DE beam energy dissipation capacity, strength, ultimate deflection, stiffness, crack width development, and crack prevention are investigated. The results show that improvements of 75%, 102.4%, and 102.8%, respectively, in the maximum load, stiffness and energy dissipation capacity of composite DE beams was achieved by rising the AH/AC ratio from 1.76 to 3.53. Furthermore, there was consistency between the theoretically expected loads and the experimental results.