Residual capacity of blast-damaged reinforced concrete columns
The aftermath of the Oklahoma City Bombing in the United States led to intense research in the progressive collapse potential of buildings subjected to blast loading. The research works did not, however, address situations where columns in buildings do not fail but suffer some amount of damage under the effect of blast loading. The challenge faced by blast hazard engineers is assessment and determination of residual capacity of blast-damaged columns. This paper presents the results of a residual capacity test program of blast-damaged full-scale reinforced concrete columns. Eight of the columns, previously tested under live explosion loading in the near-field (z 1.0 m/kg1/3) range were tested under static condition to determine their residual capacity. Four undamaged companion columns were also tested and their response compared with that of the blast-damaged columns. In general, two columns with different transverse reinforcement spacing were tested: Conventional and seismic columns. The columns were subjected to axial compression loading up to the service load level of 1000 kN and then loaded in third-point lateral loading until failure. All the previously blast-damaged columns were capable of resisting the service load. Thus, they possessed enough post-damage strength to remain in service. The reduced transverse reinforcement spacing in the seismic columns resulted in a higher residual capacity compared to the conventional columns which had larger transverse reinforcement spacing. Also, the results show that the lower level of damage sustained by columns tested at larger scaled distance resulted in higher residual capacity.
|Keywords||Blast-damaged, Near-field, Residual capacity, Scaled distance, Transverse reinforcement|
|Conference||Canadian Society for Civil Engineering Annual Conference and General Meeting 2017: Leadership in Sustainable Infrastructure|
Isaac, K. (Kwaffo), & Braimah, A. (2017). Residual capacity of blast-damaged reinforced concrete columns. In Proceedings, Annual Conference - Canadian Society for Civil Engineering (pp. 433–441).