Shrinkage Admixture

Shrinkage reducing admixtures when added to concrete during the batching stage, can significantly reduce both the early and long term drying shrinkage. This is achieved by treating the ‘cause’ of drying shrinkage within the capillaries and pores of the cement paste.

This type of admixture should not be confused with shrinkage compensating materials which are normally added at above 5% on cement and function by creating an expansive reaction within the cement paste to treating the ‘effects’ of drying shrinkage.

Shrinkage reducing admixtures can be used in situations where shrinkage cracking could lead to durability problems or where large numbers of shrinkage joints are undesirable for economic or technical reasons.

These admixtures can be used to great advantage in slabs, bridge decks, structures, and repair work where cracking can lead to steel reinforcement corrosion problems, but maintaining effective air entrainment for resistance to freezing and thawing damage can be difficult with shrinkage-reducing admixtures.