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

• Published in: Materials letters 2020-11, Vol.278, p.128464, Article 128464
• Main Authors: Yang, Jin, Zeng, Jingyi, He, Xingyang, Su, Ying, Tan, Hongbo, Strnadel, Bohumír
• Format: Article
• Language: English
• Subjects: Carbide slag; Cement; Cemented carbides; Compressive strength; Early-age strength; Hydration; Materials science; Nanoparticles; Nucleation seed; Portland cements; Powder technology; Wet-grinding
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/j.matlet.2020.128464

•Nano-carbide slag seed was prepared with wet-grinding method.•The initial and final setting time was greatly shortened by 61.4% and 51.7%.•The early-age hydration kinetic of cement was notably accelerated by nano-CS seed.•The 8-hour compressive strength was greatly enhanced by the nano-CS seed by 3350%. 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.