The recent spate of building collapses in Mumbai and neighbouring Thane has prompted experts to investigate whether only established causes like seasonal cycles of summer, monsoon and winter are the causes of deterioration in the Reinforced Cement Concrete (RCC) structures. Seasonal cycles cause rusting of steel, which leads to cracks and ultimately weakening of the structure. According to experts, shortsightedness of societies on the load-bearing capacities of the buildings has been one of the main reasons for decreasing the life of the structures. Krishnaraj Rao, an expert in the field of housing, who has found few reasons behind early damage or collapse of a building, said that every passing year the load-bearing capacity of the RCC of buildings deteriorates by a small percentage like 0.2 to one per cent. In older buildings, deterioration is at a faster rate of one per cent every year. If this deterioration is attended to on a timely basis the rate of deterioration can be reduced to 0.5 per cent, effectively increasing its life span by many years, he informed. “Unfortunately, many buildings have turned into ‘sick’ buildings over the past decade by short-sighted cooperative societies neglecting them in the lust for getting them declared as ‘dilapidated’, so that they go into commercial redevelopment. The load-bearing capacity of the RCC of such buildings deteriorates by five to ten per cent. These buildings are like time bombs ticking away, waiting to collapse,” said Mr Rao. Chetan Raikar, a structural engineer concurred with Mr Rao and said, “In the monsoon, the rain-water seeps into the walls and ceilings of such neglected structures, increasing their weight by several thousand kilograms. This additional weight is distributed unevenly on the RCC frame, making it extremely vulnerable to sudden structural failure. These buildings cannot continue to be occupied. Ignoring them is criminal negligence on the part of the government and municipal corporations.”
