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 C 4 A 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781003061021/ccc586b1-603a-4f92-8511-dad2c1cb28b1/content/inline1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 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, C 4 A 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781003061021/ccc586b1-603a-4f92-8511-dad2c1cb28b1/content/inline2.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 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.
