PREVent-C admixture is a specially formulated powder that provides dual functionality to prevent cracking or curling caused by shrinkage. PREVent-C can reduce shrinkage-induced cracking by as much as 90 to100%, depending on mix design and amount of PREVent-C used. A minimum of 80% shrinkage reduction can be expected in most cases. Based on new, innovative technology developed by PremierCPG, the material is designed to facilitate expansion of concrete at the same rate as drying shrinkage during the curing period, and to reduce the capillary surface tension of pore water. Surface tension of capillary pore water has been linked to formation of a meniscus during hydration, which accounts, at least partially, for shrinkage. Expansion ceases within 28 days during hydration and does not continue once the concrete has hard- ened. PREVent-C has no known detrimental effects on either plastic or hardened properties of concrete and cementitious mixes. In air-entrained concrete, a small increase in air-entraining admixture may be necessary to obtain desired air content. Admixture meets ASTM C-494 Type S standards.
PREVent-C can be used in all types of concretes and mortars, whether cast-in-place, mass, precast or prestressed. The material can be used in straight Portland cement mixes or blended cement mixes. Typical applications include bridge decks, parking structures, dams, runways, stadiums, flooring applications, decorative concrete, and masonry or tile grouts and mortars. The material is especially effective where concrete is highly restrained, like with most steel or other reinforced concrete applications. It is also effective with both air-entrained and non-air entrained concrete. Because it is a free-flowing powder, PREVent-C can be pre-blended with dry packaged mixes, mortars and grouts, or added at the time of use. The material also is effective for use with shotcrete mixes. PREVent-C reduces both drying and autogenous shrinkage-induced macrocracks and microcracks in concrete, which enhances its sustainability. PREVent-C does not contain chlorides or other materials that could contribute to corrosivity of reinforcing steel.
Shrinkage, Cracking, Prevention in Concrete and Cement.