石膏、硅灰对硅酸盐胶凝材料早期抗压强度的影响

Influence of Gypsum and Silica Fume on Early Compressive Strength of Portland Cementing Material

为了研究石膏、硅灰对硅酸盐胶凝材料早期强度的影响,分别测试了石膏、硅灰不同掺量下的胶凝材料的4h、1 d、28 d的抗压强度。利用X射线衍射仪和扫描电子显微镜分析了水化产物的微观结构特征。研究表明,在一定的试验范围内,胶凝材料的抗压强度随石膏的增加而变大,掺量为0.75%时最佳,4 h和1 d的抗压强度分别达到5.8 MPa和63.4 MPa;硅灰掺量从0%增长到15%,胶凝材料的各龄期抗压强度均随掺量的增加而呈增长趋势;硬化浆体的微观结构特征表明,一定的试验范围内,石膏使体系中的AFt数量增加,硅灰使体系中的C-S-H凝胶增多,且硅灰未水化的细小颗粒体有效填充硬化浆体的孔隙。

In order to study the influence of gypsum and silica fume on the early compressive strength of portland cementing material,we test the compressive strength of cement with different content of gypsum and silica fume at 4 h,1 d and 28 d respectively. The microstructure characteristics of hydration products were analyzed by X-ray diffraction and scanning electron microscope. In a certain range,research shows that the compressive strength of cementing material increases with the content of gypsum increases,the compressive strength reaches peak when the content is 0. 75%,and compressive strength reached 5. 8MPa and 63. 4 MPa at 4 h and 1 d. Silica fume increased from 0% to 15%,the compressive strength of cementing material increased by the content went up. The microstructure characteristics of the hardened cement paste shows that in,a certain range of gypsum to brought the amount of AFt in the system increased,the silica made the C-S-H get increased in the system,and unhydrated silica filled the pore of system.