ABSTRACT

Cement mixture with calcite-ettringite seeds (CE seeds) was investigated in terms of early hydration and mechanical property. The ettringite crystals of ettringite seeds (E seeds) exhibited needle-like shapes with lengths of approximately 3 μm, and the ettringite crystals of CE seeds exhibited rodlike shapes with lengths less than 1 μm. A dense growth of network-structured ettringite and calcium silicate hydrate (C–S–H) was observed. The amount of cement hydrates was analysed by thermal analysis, and the weight loss of the hydrates was 1.62% (E seeds) and 1.79% (CE seeds) at approximately 104°C, indicating that the amount of hydrates was higher in the mixture with CE seeds. The average pore diameter and porosity of the mixtures decreased from 145 to 79 nm and from 14.88% to 13.89% with the addition of CE seeds. The initial and final setting times of the mixture with CE seeds were 20 and 21 min, which were 4.76% and 8.70% shorter than the setting times of mixture with E seeds. The compressive and flexural strengths of the mixture with CE seeds were 6% and 10% higher than those of the mixture with E seeds, respectively.

摘要

研究了具有方解石-钙矾石种子（CE 种子）的水泥混合物的早期水化和机械性能。钙矾石种子（E 种子）的钙矾石晶体呈针状，长度约为 3 μm，CE 种子的钙矾石晶体呈棒状，长度小于 1 μm。观察到网状结构钙矾石和硅酸钙水合物（C-S-H）的密集生长。通过热分析法分析水泥水合物的量，在约104℃时，水合物的失重分别为1.62%（E种子）和1.79%（CE种子），说明混合料中水合物的量较高。 CE种子。添加 CE 种子后，混合物的平均孔径和孔隙率从 145 nm 降低到 79 nm，从 14.88% 降低到 13.89%。CE种子混合物的初凝和终凝时间分别为20和21分钟，比E种子混合物的凝固时间短4.76%和8.70%。CE 种子混合物的压缩和弯曲强度分别比 E 种子混合物高 6% 和 10%。