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Further Insights Into Calcium Sulfoaluminate Cement Expansion, Craig W. Hargis, Barbara Lothenbach, Christian J. Müller, Frank Winnefeld
Further Insights Into Calcium Sulfoaluminate Cement Expansion, Craig W. Hargis, Barbara Lothenbach, Christian J. Müller, Frank Winnefeld
Craig Hargis
There is still an ongoing debate on the mechanisms of expansion of calcium sulfoaluminate (CSA) cements, which can be either favourable, for example, in shrinkage compensating construction materials, or deleterious in cases of excessive expansion. In order to expand on previous studies, CSA cements with molar ratios (M) of calcium sulfate/ye’elimite of 0·1, 1, 1·5 and 2 were investigated from 30 min to 182 d. All systems showed expansion, and expansion was found to increase with increasing gypsum content. The sample with M= 2 showed a high expansion and severe cracking after 1 d of hydration. Based on the pore …
Effect Of Volcanic Ash Pozzolan Or Limestone Replacement On Hydration Of Portland Cement, Kemal Celik, Craig W. Hargis, Rotana Hay, Juhyuk Moon
Effect Of Volcanic Ash Pozzolan Or Limestone Replacement On Hydration Of Portland Cement, Kemal Celik, Craig W. Hargis, Rotana Hay, Juhyuk Moon
Craig Hargis
The replacement of Portland cement (PC) with either supplementary cementitious material (SCM) or fillers, such as natural pozzolans (NP) or limestone powder (LP) respectively, is known to affect the chemical properties of concrete, thus influencing its fresh and hardened properties. This study investigated the effects of volcanic ash NP or LP on setting time, normal consistency, hydration, and strength properties of cement paste and mortar while following the chemical changes that were a direct result of the substitution. While both materials were found to increase water demand, NP at 30% and 50% replacement levels increased setting time while LP at …