SULPHATE RESISTING PORTLAND CEMENT

SULPHATE RESISTING PORTLAND CEMENT

Sulphate resisting cement is a Portland cement and mainly differs from Ordinary Portland cement in that its chemical components in the raw mix are generally adjusted so that , after burning , the compound tricalcium   aluminate is reduced to something less than 5 per cent. It is the tricalcium aluminate that is attacked by sulphates in ground waters,and consequently Sulphate Resisting Portland cement is able to resist attacks of sulphate concentration up to certain limited amounts.

                     Such sulphate concentration are frequently found in the ground in many parts of Great Britain and elsewhere, and where these are greater than 0.5 per cent in the soil, or 100 parts in 100,000 parts of ground water , are liable to cause disintegration of concrete made with Ordinary Portland cement , and the use of Sulphate Resisting cement becomes necessary. where sulphate concentrations exceed 2 per cent in the soil or 500 parts in 100,000 parts of ground water , the protection given by sulphate  resisting Portland cement  normally ceases to be effective , and consideration has to be given to the use of high Alumina cement. The suphate concentration of sea water is generally only about 220 parts per 100,000.

                    Whenever the use of special cement is considered, it is best to seek advice from the cement manufacturers; and satisfactory results can then only be achieved using compact dense concrete free from voids or excess mixing-water. The use of special cement will not compensate for weak mixes or poor workmanship.

 Credit to :- OSCAR FABER'S