How to prevent sulphate attack on concrete

Exposure to sulphate attack : 

Below, we have recommendations to prevent sulphate attack in concrete, the type of cement, maximum free water/cement ratio and minimum cement content for preparing concrete mix, which are required at different sulphate concentrations in near-neutral ground water having pH of 6 to 9.

For the very high sulphate concentrations in Class 5 conditions, some form of lining such as polyethylene or polychloroprene sheet; or surface coating based on asphalt, chlorinated rubber, epoxy; or polyurethane materials should also be used to prevent access by the sulphate solution.

REQUIREMENTS FOR CONCRETE EXPOSED TO SULPHATE ATTACK

How to prevent sulphate attack on concrete mix
How to prevent sulphate attack on concrete mix

Look on Environment Exposure Condition Concrete

Take a Note on Other Precaution thing before referring above table that is prevention of Sulphate attack on Concrete

  1. Cement content given in this table is irrespective of grades of cement. 
  2. Supersulphated cement is generally restricted where the prevailing temperature is above 40°C. 
  3. Supersulphated cement givens an acceptable life provided that the concrete is dense and prepared with a water-cement ratio of 0.4 or less, in mineral acids, down to pH 3.5. 
  4. The cement contents given in col 6 of this table are the minimum recommended. For SO, contents near the upper limit of any class, cement contents above these minimum are advised. 
  5. For severe conditions, such as thin sections under hydrostatic pressure on one side only and sections partly immersed, considerations should be given to a further reduction of water-cement ratio. 
  6. Portland slag cement conforming to IS 455 with slag content more than 50 percent exhibits better sulphate resisting properties. 
  7. Where chloride is encountered along with sulphates in soil or ground water, ordinary Portland cement with C; A content from 5 to 8 percent shall be desirable to be used in concrete, instead of sulphate resisting cement. Alternatively, Portland slag cement conforming to IS 455 having more than 50 percent slag or a blend of ordinary Portland cement and slag may be used provided sufficient information is available on performance of such blended cements in these conditions.

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