Influence of admixtures on the morphology of calcium hydroxide formed during tricalcium silicate hydration

Revisiting the microstructure of hydrated tricalcium silicate––a comparison to Portland cement

“…2). The very large CH deposits seen here in both the C 3 S and alite pastes have been observed previously in triclinic C 3 S paste [1,[16][17][18]]. It appears, however, that these large CH agglomerates did not form in the alite paste studied by Jennings and Parrott [5].…”

Changes in portlandite morphology with solvent composition: Atomistic simulations and experiment

“…The identification of the low index [00.1] and [10.0] surfaces was expected as these surfaces are part of the hexagonal platelet shape reported as the morphology of naturally found portlandite minerals [28] and of portlandite grown in cementitious systems in the presence of sulfates [4,5,27]. The presence of the higher index [20.3] surface was more unexpected.…”

The influence of sodium salts and gypsum on alite hydration

“…Berger and McGregor [13] observed that a platelet-like morphology with a c and a crystallographic axis ratio below 0.5 was dominant when C 3 S hydrated in the presence of sulfate and hydroxides [13]. At equal degrees of hydration, hydroxide and, to a lesser extent, sulfate were reported to induce the formation of smaller and more numerous particles.…”

“…OH − ions were conjectured to speed up growth in the direction of the plate edges ([10.0] surfaces) promoting thinner platelets compared to sulfate, which agrees with previous findings in Refs. [13,14,16].…”