By
KAUSHAL KISHORE
Materials Engineer, Roorkee
The problem of Alkali-silica reaction was believed to be non-existent in India till 1983, when its occurrence was diagnosed in two concrete dams. This paper describes this problem with respect to Indian aggregates and cement. A rapid method of test for alkali-aggregate reaction is investigated and described in the paper.
INTRODUCTION
The most common causes of deterioration in structural concrete with steel reinforcement in it are
- carbonation and chloride penetration leading to corrosion of steel resulting cracking and spelling of the concrete cover.
- inadequate cover to reinforcing steel Less common causes of deterioration in clude,
- freezing and thawing
- sulphate attack
- alkali-aggregate reaction.
There are three types of alkali-aggregate reactions, namely the alkali-silica, alkali-silicate and akali-carbonate reactions. Deterioration due to the alkali-silica reaction is more common and this paper refers to this aspect.
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