Beam–column subassemblies with construction joint in columns above and below the beam Available to Purchase

Construction joints in columns are unavoidable in multi-storey reinforced-concrete structures. According to ACI 224.3R-95, construction joints in columns are to be provided below the beam for lower storey columns and above the floor slab for upper storey columns. A review of the literature reveals that little attempt has been made so far to study the effect of cyclic loading on beam–column subassemblies with construction joints in the column above and below the beam. In the present paper, one-third scaled beam–column joint specimens were designed as per relevant provisions of the Indian standard code of practice and detailed as per ductile detailing procedures. Flexural strength ratios of the specimens were 1·2, 1·4, 1·7 and 2·0. Specimens were cast in stages, providing construction joints in the column as per ACI 224.3R-95 to simulate in situ construction. It was observed that ductility, initial stiffness and energy dissipation capacity reduced by 30–44%, 16–19% and 53–64%, respectively, in specimens with double construction joints in the column compared to control specimens.