Experimental Assessment of Progressive Collapse of Reinforced Concrete Beam-Column Assemblages

Document Type : Original Article

Authors

1 Professor of Reinforced Concrete Structures, Department of civil engineering, faculty of engineering (Shoubra), Benha University,108 Shoubra St., Shoubra, Cairo, Egypt

2 Associate Professor, Department of civil engineering, faculty of engineering (Shoubra), Benha University,108 Shoubra St., Shoubra, Cairo, Egypt

3 Professor of Structures, Department of civil engineering, faculty of engineering (Shoubra), Benha University,108 Shoubra St., Shoubra, Cairo, Egypt

4 Assistance Professor, Department of civil engineering, faculty of engineering (Shoubra), Benha University,108 Shoubra St., Shoubra, Cairo, Egypt

Abstract

This paper introduces the experimental program implemented to study the load-carrying capacity of seven reinforced concrete beam-column assemblages under monotonic vertical load against progressive collapse due to removal of the interior column. The specimens were designed and detailed according to the Egyptian code provisions. The specimens were one-quarter of the full scale and designed with and without seismic detailing to verify the effect of reinforcement detailing and flanges on the assemblage structural behavior. Each specimen represented a two-consecutive beam spans subsequent to the elimination of the first story interior column. In all assemblages, the external two columns were restrained against the vertical and the horizontal deformations and loads were applied monotonically at the top of the interior column stub. For each load step, the results of mid-span deflection, concrete strains, reinforcing steel strains, and load capacities were documented. The tests showed that the compressive arch action (CAA) improve the beam-column assemblage flexural capacity. The arching capacity was noticed to be a function of the longitudinal reinforcement ratios, seismic and non-seismic detailing, and the existence of concrete flanges. The response of the beam-column assemblages is evaluated through determinations of the displacement ductility level, the amount of absorbed energy, the contribution of the compression arching action, and activation of the catenary action. The test results are validated by two existing theoretical models through the calculations of the assemblage peak capacity.

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