The properties of a hydrated high-performance calcium sulfoaluminate (CSA) cement were investigated by means of XRD, DTA-TGA, SEM analyses and mercury porosimetry. The early hydration behaviour was strongly influenced by the high (0.78) stoichiometric water-solid mass ratio required by the reaction of with calcium sulfate and water towards ettringite and aluminium hydroxide. The high rate of this reaction resulted into a rapid depletion of water within a relatively short curing period and both full consumption of reactants and hydration of other CSA cement components were hindered. However, conversion degrees of 0.60 and 0.87 were obtained at 3 hours and 28 days respectively, for CSA cement pastes cured with a water-cement ratio equal to 0.45. Both the fast formation of ettringite and the rapid establishment of prevailing low-porosity regions can play a very important role in regulating the technical behaviour of high-performance CSA cements
Early hydration of calcium sulfoaluminate-based cements for structural applications
MARROCCOLI, MilenaWriting – Review & Editing
;TELESCA, ANTONIOWriting – Original Draft Preparation
;VALENTI, Gian Lorenzo
Writing – Review & Editing
2007-01-01
Abstract
The properties of a hydrated high-performance calcium sulfoaluminate (CSA) cement were investigated by means of XRD, DTA-TGA, SEM analyses and mercury porosimetry. The early hydration behaviour was strongly influenced by the high (0.78) stoichiometric water-solid mass ratio required by the reaction of with calcium sulfate and water towards ettringite and aluminium hydroxide. The high rate of this reaction resulted into a rapid depletion of water within a relatively short curing period and both full consumption of reactants and hydration of other CSA cement components were hindered. However, conversion degrees of 0.60 and 0.87 were obtained at 3 hours and 28 days respectively, for CSA cement pastes cured with a water-cement ratio equal to 0.45. Both the fast formation of ettringite and the rapid establishment of prevailing low-porosity regions can play a very important role in regulating the technical behaviour of high-performance CSA cementsI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
