Further Insights Into Calcium Sulfoaluminate Cement Expansion, Craig W. Hargis, Barbara Lothenbach, Christian J. Müller, Frank Winnefeld
Mar 2019
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 …
Aggregate Passivation: Lithium Hydroxide Aggregate Treatment To Suppress Alkali-Silica Reaction, Craig Hargis, Maria C.G. Juenger, Paulo J.M. Monteiro
Aug 2013
Aggregate Passivation: Lithium Hydroxide Aggregate Treatment To Suppress Alkali-Silica Reaction, Craig Hargis, Maria C.G. Juenger, Paulo J.M. Monteiro
Craig Hargis
Alkali-silica reaction (ASR) continues to be a concrete durability problem despite the many physical and chemical mitigation techniques known to successfully prevent it. The research presented herein tested a new method to limit ASR: aggregate passivation. A lithium silicate layer was created on reactive natural siliceous aggregate surfaces by treating the aggregates in a lithium hydroxide solution prior to use. A 4 M LiOH treatment was found to be superior to a 2 M LiOH treatment in producing a lithium silicate passivation layer and in reducing expansion due to ASR. The use of passivated aggregates greatly reduced expansion in accelerated …
Reply To The Discussion Of The Paper “Understanding Expansion In Calcium Sulfoaluminate-Belite Cements”, Irvin A. Chen, Craig W. Hargis, Maria C.G. Juenger
Dec 2011
Reply To The Discussion Of The Paper “Understanding Expansion In Calcium Sulfoaluminate-Belite Cements”, Irvin A. Chen, Craig W. Hargis, Maria C.G. Juenger
Craig Hargis
Reply to the discussion of the paper “Understanding expansion in calcium sulfoaluminatebelite cements” by G.L. Valenti, M. Marroccoli, M.L. Pace, A. Telesca.
