The use of Superabsorbent Polymers to Mitigate Shrinkage of Concrete

Superabsorbent polymers (SAP) are a new type of admixture. They can store many times more water than their own weight. They can be used for internal curing of concrete and for mitigation of shrinkage. By adding 0.7 % SAP by mass of cement, autogenous shrinkage of low water-cement ratio concrete can be suppressed completely. By adding only 0.35 %, autogenous shrinkage can be reduced by 80 % compared to concrete without SAP. Total shrinkage of drying concrete (the sum of autogenous and drying shrinkage) is also reduced considerably. The paper reports about experimental investigations on cement paste and concrete which show the favorable effect of SAP on shrinkage. Results will be shown and discussed in the light of the mechanism of autogenous shrinkage and the effect of SAP on the water balance in concrete.