Temperature Dependency of Short-Term Length-Change and Desorption Isotherms of Matured Hardened Cement

Abstract

Short-term length-change isotherms and desorption isotherms of matured hardened cement paste were measured at different temperature conditions, namely, 20, 30, 40, 50, and 60℃. For the short-term length-change isotherms, higher temperature conditions resulted in a smaller drying shrinkage. This trend was largely controlled by the microstructural reorganization of the calcium-silicate-hydrates in the cement paste at elevated temperatures. The experimental results suggest that a portion of the evaporable water did not contribute to the shrinkage. In addition, based on the relation-ships between the incremental strain and the incremental evaporable water content, with a starting relative humidity of 5%, consistent trends were observed for the incremental strain and the incremental evaporable water when the incremental evaporable water content was less than 0.08 g/g-dried hcp. The microstructural reorganization pathways for elevated temperature and/or for drying were confirmed to be identical.