Application of Engineered Cementitious Composites to Precast Beam-Column Sub-Assemblage under Column Removal Scenarios

Abstract

This paper presents an experimental study on the behaviour of precast beam-column sub-assemblages under middle column removal scenarios. By using Engineered Cementitious Composites (ECC) in the beam-column joint and the cast-in-situ structural topping, the resistance and deformation capacity of the sub-assemblage was investigated. Besides, the compatible deformation between ECC and longitudinal steel reinforcement was observed at the initial stage, until the tensile strain capacity of ECC was exhausted. With increasing vertical displacement, a major crack was formed in the plastic hinge region, and severe localisation of rotation was recorded at large deformations. Top reinforcement in the beam eventually ruptured near the face of the end column stub, leading to collapse of the sub-assemblage. Conclusion was drawn from the experimental results that application of ECC to the precast beam-column sub-assemblage limits its deformation capacity as a result of higher bond strength between ECC and reinforcing bars.