In last few years there has been increasing interest in alternative approaches to durability of marine structures world wide as traditional approach of improving durability of reinforced concrete structures has been found outdated to the growing problem of chloride –induced corrosion. Most of the countries world wide have switched to corrosion resistant stainless steel reinforcement.
“Countries including USA, New Zealand, Australia and UAE have made it mandatory to use stainless steel reinforcement in coastal areas for marine structures including bridges. Stainless steel reinforcement re-bars are emerging as an excellent sustainable solution for the concrete bridges in coastal and hill areas. The stainless steel reinforcing bars provide long life into concrete structures especially in the hills, coastal areas, ports, airports, bridges, high rise buildings and water treatment plants as these bars do not ever corrode and thus concrete failure due to spalling is avoided.” Said Mr Yatinder Pal Singh Suri, ,Managing Director and India Head, Outokumpu India, one of the largest stainless steel making company in the world and former President, IIT Kharagpur Alumni Association.
Mr Yatinder Pal Singh Suri
Managing Director and
India Head, Outokumpu India
“Since stainless steel does not corrode, the concrete continues to offer a maintenance free life of over 100 years. There are global examples to showcase this. Our planners must make use of stainless steel re-bars mandatory in corrosion prone areas of the bridge. This would mean substituting just 5-10 per cent of the total rebars to be used in a bridge from carbon steel to stainless steel. The cost of the bridge project cost may go up by a 2-3 per cent but the life will go up to 100 years that too almost maintenance free.” Said Mr Suri.
“A few years back Maharashtra Government had made it mandatory use of stainless steel reinforcement in its Two major projects Manori creek bridge, sea link 2nd phase (WFSL) and Mithi river bridge. But after some time the order on use of Stainless steel reinforcement as withdrawn by the government” said Mr Suri.
“Duplex Stainless steel reinforcing bars are although more expensive than carbon steel but it can be used selectively in failure prone zones only thus increasing the project cost marginally and at the same time we can get over 100 years maintenance free life which means lots of savings by reducing the ongoing repair and maintenance costs of structures like bridges, coastal area projects, water treatment plants, high rise buildings and highways” Mr. Suri said .
“Over the last 3 decades, premature deterioration of reinforced concrete structures has become a serious problem worldwide due to corrosion of the embedded steel. The estimated cost of repair is in excess of USD 550 billion” said Mr. Suri.
“The other benefits of stainless steel reinforcement include significant increase in durability and reduction in repair and maintenance costs, elimination of concrete sealants and reduction in thickness of the concrete cover “he added.