Expansive cement blend for use in shrinkage-compensating mortars

To reduce the size and amount of shrinkage cracks that frequently occur in Portland cement concrete, expansive cements have been developed, namely sulfoaluminate-type cements. These cements are increasingly used for the repair of concrete structures. This paper reports an approach to general concepts associated with sulfoaluminate-type cements. The procedure for mix proportioning of the calcium sulfoaluminate cement blend using kaolin as a source of aluminates is described and the results of an experimental investigation of the behaviour of expansive cement mortars with respect to expansion and strength characteristics are presented. The hydrated crystalline products are also identified.