Abstract

This study evaluates two calcium-silicate-hydrate (C-S-H) nanoseeds: tobermorite (TOB) and foshagite (FOS), for accelerating hydration and strength gain in cement systems. TOB and FOS seeding at 1.5%wt generated 7 and 3 times more heat of hydration than the control at hour four. In addition, 1.5%wt TOB and 1%wt FOS seeding increased 1- and 3-day compressive strength (f_c) by 40 and 30% and flexural strength (f_f) by 20 and 23%. Twenty-eight-day f_c and f_f increased by up 30 and 17% with 1.5%wt TOB. The contribution of C-S-H seeds to the total global warming potential of seeded mortars was 9–15% and down to 2–5% using recycled steam. After the improvements in 28-day f_c were factored in, the carbon intensity index of seeded mortars was lower than the control by up to 20%. Based on these initial results, the studied hydrothermally synthesized C-S-H seeds appear sensible from the strength development and environmental stances.

摘要

本研究评估了两种硅酸钙水合物 (CSH) 纳米种子：托贝莫来石 (TOB) 和硅酸钙石 (FOS)，用于加速水泥体系中的水合作用和强度增加。以 1.5%wt 接种的 TOB 和 FOS 在第四小时产生的水化热比对照多 7 倍和 3 倍。此外，1.5%wt TOB 和 1%wt FOS 接种使 1 天和 3 天的抗压强度 ( f _c ) 分别提高了 40 % 和 30%，弯曲强度 ( f _f ) 分别提高了 20 % 和 23%。28 天的f _c和ff分别增加了 30% 和 17%，TOB 重量百分比为 1.5% _。CSH 种子对播种砂浆的全球变暖总潜力的贡献为 9-15%，而使用回收蒸汽则降至 2-5%。经过28天的改进后_考虑到c因素，播种砂浆的碳强度指数比对照低达 20%。基于这些初步结果，所研究的水热合成 CSH 种子从强度发展和环境立场来看似乎是合理的。