纳米C-S-H对矿粉-水泥体系水化的影响

C-S-H是通用硅酸盐水泥主要的水化产物,对水泥基材料的性能起着十分重要的作用,但水泥水化产物复杂,难以从水化产物中分离出纯净的C-S-H并研究其对水泥基材料的影响。故本文通过双分解法制备了纳米C-S-H(NC)颗粒,并将其掺入矿粉-水泥体系中,通过无接触式电阻率测定仪、X射线衍射仪、差热分析仪(DSC-TG)、扫描电镜、压汞测试仪(MIP)等探究了NC对矿粉-水泥体系水化的影响。研究发现,在1%~4%(质量分数)掺量范围内,掺入NC可缩短基体的凝结时间,并为水泥早期水化提供更多的活性位点,加速水化产物的形成和沉淀,促进水化产物之间的搭接,从而降低了基体孔隙率并使基体早期强度和水化浆体电阻率均有所提升。

Effect of Nano C-S-H on Hydration of Slag Powder-Cement System

C-S-H is the main hydration product of common Portland cement,which plays a very important role in the properties of cement-based materials.However,the hydration products of cement are complex,and it is difficult to separate pure C-S-H from the hydration products and explore its influence on cement-based materials.Therefore,nano C-S-H(NC)particles were prepared by the double decomposition method in this paper and mixed into the slag powder-cement system.The influence of NC on the hydration of slag powder-cement system was investigated by means of non-contact electrical resistivity measurement,XRD,DSC-TG,SEM,and MIP.Results show that in the range of 1%to 4%(by mass)dosage,the addition of NC shortens the setting time of matrix,and provides more nucleation sites for cement hydration,accelerates the formation and precipitation of hydration products.It also promotes the bond between the hydration products,thus reducing the porosity and increasing the early strength and resistivity of cement matrix composites.