Effect of C-S-H-PCE and TEA on performances of lithium slag-cement binder

Abstract

In order to promote rheological behavior and strength enhancement of lithium slag-cement binder at early age, synergistic adoption of synthetic calcium silicate hydrates (C-S-H)/polycarboxylate (PCE) and triethanolamine (TEA) into lithium slag-cement binder was conducted. The rheological performance, setting behavior, hydration process and microstructure of blended cement were analyzed. The results showed that the adoption of C-S-H-PCE improved the rheological behavior of fresh binder, shown as decreased viscosity and yield stress. The addition of TEA weakened the rheological behavior of fresh binder, shown as elevated viscosity and yield stress. Both C-S-H-PCE and TEA accelerated the hydration process of lithium slag-cement composite binder, shortened the setting time, and promoted compressive strength enhancement at early ages. C-S-H-PCE provided nucleation sites for early hydration products of silicates, while TEA generated the transformation of AFt to AFm. The synergistic action of C-S-H-PCE and TEA accelerated the formation and growth of hydration products, and hence contributed to more compact and dense microstructure of hardened matrix.