RussTech shrinkage-compensating admixtures significantly decrease drying shrinkage in all Portland cement based mixtures. They are not expansive materials, but they function by blocking capillaries of pore water, which is the major mechanism that causes drying shrinkage in concrete. Shrinkage-compensating admixtures, when added to concrete at a rate of 2 % by weight of cementitious material, can reduce shrinkage (ASTM C 157) by up to 80% at 28 days of age and by up to 50% at one year of age.
