Effect of calcium silicate hydrate - polycarboxylate ether (C-S-H PCE) nanocomposite as accelerating admixture on early strength enhancement of slag and calcined clay blended cements

The effectiveness of a self-synthesized C-S-H-PCE nanocomposite on early strength development of slag and calcined clay blended cements (35 wt% slag or calcined clay) was studied. Addition of C-S-H-PCE was found to substantially increase mortar strength at early ages, particularly after 6-24 h of curing. Isothermal heat flow calorimetry and in-situ XRD measurements indicate that silicate hydration in cement is significantly accelerated. Most remarkably, C-S-H-PCE also speeds up the pozzolanic reaction of slag and calcined clay and stimulates the formation of hemicarbo aluminate (Hc), especially in calcined clay cement. Thus, C-S-H-PCE can foster more widespread use of CEM II/III.