Effectiveness of a calcium silicate hydrate - Polycarboxylate ether (C-S-H-PCE) nanocomposite on early strength development of fly ash cement

C-S-H-PCE nanocomposites are known seeding materials for Portland cement. Here, the effectiveness of a C-S-H-PCE admixture on early strength development of a fly ash blended cement (35 wt% fly ash) was investigated. It was found that addition of C-S-H-PCE drastically increases the compressive strength of mortar and concrete, particularly at 6-24 h of hydration. XRD and calorimetric measurements confirm that the hydration of C3S/C2S in cement is greatly accelerated. Most interestingly, however, the C-S-H-PCE nanocomposite also stimulates the pozzolanic reaction of fly ash, thus explaining the exceptionally high early strength values. Accordingly, C-S-H-PCE might also be useful in other CEM II cements holding pozzolanic materials. (C) 2018 Published by Elsevier Ltd.