Interventions of Retarders on the Hydration Process of CaO Expansion Clinker

Abstract

The volume deformation test, differential scanning calorimetry and chemical titration technique were used to experimentally research the interventions of retarders on the free autogenous volume deformation of cement paste doped with CaO expansion clinker at different ages systematically, as well as the hydration rate and hydration process of CaO expansion clinker. Two types of retarders were used as following: sodium gluconate and sodium citrate. The experimental results show that the two retarders can delay the hydration process of CaO expansion clinker, slow down its hydration rate both in pure water and cement paste. At the same time, the free autogenous volume deformation of cement paste was increased. In this sense, the use of retarders is favorable to improve the expansion efficiency of CaO expansion clinker.