Experimental investigation of reinforced concrete exterior beam-column subassemblages for progressive collapse

Abstract

This paper presents experimental investigations on the performance

of reinforced concrete (RC) exterior beam-column subassemblages

under progressive collapse scenario (loss of exterior ground column).

The amount of resistance the beam-column subassemblages could

provide the structural frame against progressive collapse is of great

value in predicting the performance of buildings and for determining

the stability of buildings during search-and-rescue operations. Two

series of test specimens were tested under monotonic loading to

simulate gravity load on the damaged structure after a blast event

(assuming the damaged structure remained standing). In the first

series (NS series), the overall performance of the beam-column

subassemblages based on as-built detailing of structures commonly

found in Singapore were assessed. In the second series (LS series),

improvements/modifications were made to the as-built design by

incorporating some seismic detailing. The experimental results

highlighting behavior, such as force-displacement responses, crack

patterns, and failure mechanisms, are discussed and the overall

performance of the two series were compared and evaluated. In this

investigation, extensive instrumentation both internal and external

allowed for detailed analysis of the response of the beam-column

subassemblage, which is summarized in the paper.