Investigation of the products of the dolomite reaction in Portland cement pastes

The formation of potentially deleterious reaction products from the reaction of dolomite fines in Portland cement pastes was investigated. It was shown that the reaction of dolomite fines did not follow the commonly accepted dedolomitization reaction. Instead, similar hydration phases as reported for the Portland cement containing limestone are observed, with the exception that also hydrotalcite is formed. It was shown with SEM-EDS and XRD that hydrotalcite is the only magnesium containing hydration product of the dolomite reaction, as no brucite or M-S-H were detected. In the next step of this study this reaction will be investigated in Al-rich systems.