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Description: This study has evaluated the expansion of mortar bars, cured at various elevated temperatures following a standard curing regimen, and stored at ambient temperature until measurement. None of the cements expanded when cured at temperatures of 70°C and below, even after five years of storage. Of the nine cements studied, three cements expanded when cured at 90°C, and two when cured at 80°C. The compound composition of the hydrated materials was evaluated by thermal analytical techniques, and the microstructure was assessed by optical microscopy. Thermal analysis revealed that the majority of the sulfate in the cement was present as ettringite except for one sample, with high C3A level, that had not expanded. The microstructure generally showed gaps around sand grains and cracks in mortars that showed expansive behavior. This report is also found on DVD021.
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