Effect of the Addition of Calcined Clay-Limestone-Gypsum in the Hydration of Portland Cement Pastes

Abstract

Currently, mineral additions are widely used as they favor not only the partial replacement of Portland cement, they reduces clinker production, but also provide certain chemical and physical properties that make concrete more durable. The variation of the water-cement ratio, the use of setting retarding additives and the addition of Cementitious Supplementary Materials (MCS) are factors that have a great influence on the hydration of the cement and the formation of the phases of a hydrated cement paste. That is why this research focuses on evaluating the effect of the active mineral addition of calcined clay, limestone and gypsum (LC2), in the cement hydration process. The work consists of several stages: first, a study is made of the variations that are made to the water to define the protocol and the amount of addition to study (30%); In a second stage, calorimetry and chemical shrinkage tests are carried out on cement pastes and a final stage where the influence of the addition on the hydration processes of the pastes is analyzed. This research provides a way of replacing Portland cement through the use of mineral additions, as is the case of LC2, which are in turn within the Construction Industry, to be a sustainable way of production of materials in Cuba.