Nano-carbide slag seed as a new type accelerator for Portland cement

Abstract

In present work, a novel nano-CS seed was prepared by wet-grinding method and added to cement to accelerate the early hydration. With 5% nano-CS seed, the initial and final setting time was clearly shortened by 61.4% and 51.7% respectively; the dormant period and the main hydration peak was notably advanced by 52.9% and 43.5% respectively. Early compressive strength, especially the 8-hour strength, was greatly promoted by the nano-CS seed by 3350%, with 5% nano-CS seed. It was speculated that the early-hydration and early-strength was accelerated by weakening the electrical double layer shielded around the silicate phase, thus shortening the dormant period. Results highlighted that the prepared nano-CS seed in present work is expected to be practically used as a new type accelerator.