Sulphate Attack on Concrete

Concrete may look durable but subjected to certain conditions will decay prematurely. One of the factors is the penetration of sulfates normally found in groundwater. Concrete is attacked by sulphate ions and causes a chemical breakdown. Causes of these include water-soluble sulphate-containing salts and alkali sulphates.

This may cause extensive cracking, expansion and loss of bond between the cement paste and aggregate. All this lead to overall loss of concrete strength.

How to avoid this?

1. The quality of concrete, specifically a low permeability, is the best protection against sulphate attack.

• Adequate concrete thickness

• High cement content

• Low w/c ratio

• Proper compaction and curing

2. The use of sulphate resisting cements provide additional safety against sulphate attack