Interaction of saccharides and sugar alcohols with well cement

Abstract

This paper reports on experimental investigations into the reactions of various saccharides and sugar alcohols in well (Portland) cement slurries at 90°C. At elevated temperatures the important element in saccharide chemistry is the overriding of a low activation energy barrier for the purpose of ring opening/cleavage and the formation of anionic molecules in cement slurries. The resulting experiments show a joint three-step reaction sequence for saccharides and sugar alcohols, accompanied by one set acceleration and two retardations of the cement hydration. The step-wise setting courses are explained by the spontaneous anion formation of polyhydroxy compounds owing to the Lobry de Bruyn–Alberda van Ekenstein rearrangement (keto-enol tautomerism) and charge neutralisation, as well as by well-known traditional organic–inorganic interactions. Furthermore the paper underlines the high relevance of temperature adjustment and cement aging on the course of setting of well cements.