Self-compacting concrete usually contains more flour than the conventional vibrated concrete but has a lower water-binder factor and higher dos-age of plasticiser. The high flour content, together with a possibly delay in the effect of the high-effi-ciency plasticiser, means there is a risk of relatively high early shrinkage (also referred to as capillary shrinkage) as the concrete dries out. Since the concrete is usually not able to take up the resulting tensions if expansion is impeded during this early stage, in the worst case, wide single cracks appear.
