IMPACT OF AGGRESSIVE ENVIRONMENT ON CONCRETE – A REVIEW

The present day construction industry needs an environmental friendly material which should with stand its material properties through outs its estimated life span. The material should be aesthetically pleasing, maintain balance in ecology of environment in order to take health care of it and wastages should be minimized. Concrete is one such material which full fill all the needs and lots of research has been going on for predicting its behavior in various environmental conditions. Concrete may be affected by the presence of pollutants in the environment such as carbon di-oxide, NOX, oxides of sulpher and suspended particulate matter. At present concrete is gaining special importance due to its ability to resist severe environmental conditions such as marine environment, harsh environment (high & elevated temperature), high humid regions, sulphate rich environment, acidic environment, alkaline environment, sewer environment, freeze & thaw Cycles, and et.,. These environments lead to deterioration of concrete by effecting plastic shrinkage, strength loss at later ages, decrease in compressive strength, pore structure, corrosion of steel, and decrease in service life i.e., life expectancy and durability. To overcome these problems concrete made with different types of admixtures in ordinary Portland cement like Fly-ash, Granulated Blast furnace Slag, Rice husk ash and Silica fume, or Pozzolana cements, slag cements, pumice stone concrete and low calcium flyash based concrete will serve.