The effects of varying gypsum content on thaumasite formation in a cement:lime:sand mortar at 5 degrees C

An air entrained cement:lime:sand mortar containing high purity powdered calcite was crushed and portions stored in water together with varying quantities of gypsum. All mixes are stored at 5 degrees C. The reaction products were monitored at intervals over a period of several months by means of X-ray diffraction analysis. Ettringite, later followed by thaumasite was produced by mixes of high gypsum content but only ettringite was obtained for the lower gypsum contents. (C) 1997 Elsevier Science Ltd.