A review on the influence of shrinkage reducing admixtures on concrete.

Resumo

Shrinkage cracking is a common source of distress in concrete structures. In addition to being unsightly, these cracksservetoaccelerateotherformsofdamageinconcrete,therebyshorteningtheservicelife ofstructures.Onesolution toreducethepotentialforshrinkagecrackingistoincorporateashrinkagereducingadmixture(SRA)inconcretemixtures. SRAs belong to a special type of organic chemicals (i.e., surfactants) that when mixed in water, reduce the surface tension of the liquid, and thereby reduce the magnitude of capillary stresses and shrinkage strains that occur when concrete is losing moisture. Various studies show that SRAs have proven to reduce drying, autogenous, and plastic shrinkage, which has been summarized in thisliterature.