Title : REHABILITATION AND STRENGTHENING OF DISTRESSED COLUMNS - A CASE STUDY
Authors : Narsingh Rammilan Varma, R. S. Jangid and Prakash Nanthagopalan
Publication : 13th – 16th February 2013
Volume :
Pages : 10-Jan
Price : 250
Abstract : Reinforced concrete structures constructed in aggressive environments (especially in coastal cities) coupled with poor construction practices are prime causes for rapid degradation of buildings. Lack of preventive measures, routine repairs and maintenance leads to cracking, spalling of concrete and corrosion of reinforcement in the buildings. The ingress of harmful agents (chlorides, CO2, etc) in the cracks leads to further cracking, carbonation of concrete and loss of reinforcement section. The poor design and detailing further compound the problem of deterioration and advance the onset of threshold loading conditions. This paper presents various techniques available for rehabilitation and strengthening of critically distressed reinforced cement concrete (RCC) structures, and discusses a case study of a cluster of three, stilt + 3 storied residential buildings having RCC framed structure in Indian Institute of Technology Bombay, Mumbai. The structure was highly distressed with wide open cracks, spalled concrete and corroded reinforcements. Detailed visual inspection was performed. It was observed that considerable loss of reinforcement due to corrosion had reduced their load carrying capacities. Strengthening was carried out by adding additional reinforcement and replacement of cover concrete by jacketing to those deficient members and stands effective till date. It is concluded that for structural members, especially columns, having good core concrete and with critical loss of reinforcement, jacketing with added reinforcement may be a preferred option.