Plastic shrinkage of concrete made with calcined clay-limestone cement

Abstract

Concrete made with blended cements with high clinker replacement ratios may be at higher risk of plastic shrinkage cracking when experiencing high evaporation rates immediately after casting. This paper investigates the plastic shrinkage behavior of concretes made with a cement with clinker replacement by a blend of calcined clay and limestone, which was compared to a conventional Portland cement and a Portland-limestone cement. In order to assess the risk of cracking, we studied early deformations and accompanying processes in concretes exposed to fast evaporation in a wind tunnel. As could be expected from previous studies, concretes made with both blended cements experienced higher shrinkage and cracking compared to ordinary Portland cement, mainly due to their slower hydration caused by a lower clinker amount and higher dosage of superplasticizer. However, the extent of plastic shrinkage cracking was similar with calcined-clay limestone cement and Portland-limestone cement.