水化硅酸钙晶种的制备及对水泥强度的影响

Preparation of C-S-H-phase nuclei and its effects on compressive strength of cement

为了研究水泥晶种的制备技术及对水泥强度的影响，在蒸压条件下，选取天然硅质原材料硅藻土和钙质原材料熟石灰，利用水热合成法制备C—S—H凝胶作为水泥晶种，并研究了3种钙硅材料的配制比例和不同热工制度制备的晶种对水泥强度的影响．研究结果确定了钙硅比为1．2，合成压力在0．1MPa，合成时间1～3h为水泥晶种的最佳合成工艺制度．试验结果表明：掺晶种后的C3S悬浮液液相中的钙离子析晶时间提前，缩短了凝结时间，加速c，S的早期水化；掺入晶种可有效地提高水泥的早期强度，其原因在于加晶种可以降低产物成核所需克服的势垒、促进成核、并有效抑制大晶粒的生长．

To investigate the preparation of cement nuclei and its effects on compressive strength of cement, this paper described the preparation of hydrated calcium silicate （ C - S - H - phase） nuclei hydrothermally synthesized by diatomite and lime at autoclaves conditions. The effects of C - S - H - phase nuclei prepared in different calcium silicate ratio and thermal system on the compressive strength of cement were studied. The results identified the optimal synthesis technology system of C - S - H nuclei, in which the calcium silica ratio was 1.2, synthesis pressure was 0. 1 MPa, synthesis time was 1 ~ 3 h. The results also showed that the crys- tallization time of calcium in suspension of C3S was advanced after incorporating C - S - H - phase. The setting time was shortened and the hydration of C3 S at early ages was accelerated. Therefore, C - S - H - phase can improve the early strength of cement effectively, because the seeds can lower the barrier of nucleation of the products, promote nucleation and effectively inhibit the growth of large grains.