Superplasticizer compatibility with cement properties – A study

Abstract

Portland cement has been the conventional building material down through the ages. But with passing decades materials other than cement were being added to the cementitious system from outside to improve or modify its mix properties. The role of these materials was of varying degrees starting from water reducing to viscosity modifying to shrinkage reducing to being pozzolanic to reducers or accelerators. The existing literature survey suggests that a very high range water reducer or Superplasticizers can make a cementitious mix flowable at a low water-cement ratio without segregation and bleeding – the most basic principle of a fresh cementitious mix. Portland cement without admixtures in contact with water tends to flocculate resulting in agglomeration of particles in the mix thus making the system non-lubricating. Our paper discusses the various effects of Superplasticizers on the properties of cementitious mixes and the contribution of its constituent mineral phases. More recently, a new type of Superplasticizers based on 4th generation polymers are preferred in terms of lower slump loss at a low water-cement ratio.Our paper reports the addition of high performing superplasticizer -Poly Carboxylate Ether in cement composites as per Indian Standards has resulted in a denser cementitious matrix and higher strength gain at longer terms compared to normal superplasticizers.