Steel Corrosion in Concrete – Causes & Prevention
In RCC (Reinforced Cement Concrete) work, Steel is used as reinforcement material in the form of twisted round bars of mild steel. Steel binds with concrete in a well manner and provides high tensile strength to concrete. Now steel in concrete can develop corrosion which deteriorates the material and hence the structure.
Causes of Corrosion
We look at the causes of Steel corrosion in Concrete below:
- Adding more water to cement than prescribed, increasing the water-cement ratio in excess.
- Steel Bars are rusted before placing them in concrete.
- Poorly skilled workers, staff or contractor.
- Insufficient cover to steel bars from exposed surfaces of concrete.
- Water used in preparing concrete is not pure.
- Presence of salts in environment and other atmospheric conditions.
- Using low quality of Steel Bars for the purpose.
- Congested reinforcement in small sections of concrete.
Prevention of Corrosion
Corrosion of Steel in Concrete can be prevented by following measures:
- Using proper water to cement ratio in the concrete mixture.
- Avoiding congested reinforcement especially at the intersection of beams and columns.
- Steel contact with Bricks, Soil and Wood should be avoided.
- Using good quality of Cement
- Using good quality of Bars
- Work done by experienced and skilled staff.
- Provide surface coating to concrete with Paints, Tars, Asphalts, etc.
- Clear the rust on Bars before placing them in concrete.
- Pure water should be used in the mixture.
Generally, speed of corrosion of steel in concrete is slow and doesn’t have much effect on concrete member. But in exceptional circumstances, life of concrete member is reduced with such corrosion. By following preventive measures, as mentioned above, such corrosion of steel can be avoided.