湿法研磨激发制备硅灰水泥净浆的力学性能研究

Study on Mechanical Properties of Silica Fume Cement Slurry Prepared by Wet Grinding

摘要:

为了减少硅灰在运输过程中因增密带来的负面影响。采用湿法研磨来降低硅灰的粒径大小，以提高其活性，同时研究了不同研磨转速（150和250 r?min^-1）和水磨时间（5、10、15、20和25 min）对硅灰制备水泥净浆力学性能的影响。采用SEM扫描电镜、X射线衍射仪、傅立叶变换红外光谱仪等手段，探究了水泥净浆的微观结构、水化产物和官能团的变化。结果表明，在转速250 r?min^-1、水磨20 min的条件下，硅灰的7和28 d的抗折强度和抗压强度能够显著提高，尤其是早期（7 d）的分别比基准组提升了18.4%和15.8%。说明，湿法研磨能够有效减少硅灰的团聚现象，显著改善硅灰的填充效应和火山灰活性，提高水泥净浆的力学性能。

Abstract:

To reduce the negative impact of silica fume due to the densification during transportation， wet grinding was used to decrease the particle size of silica fume and improve its activity. The effects of different grinding speeds （150， 250 r?min^-1） and water milling times （5， 10， 15， 20， 25 min） on the mechanical properties of cement slurry prepared from silica fume were compared and studied. The changes in the microstructure， hydration products， and functional groups of cement paste were investigated using an SEM scanning electron microscope， X-ray diffractometer， and Fourier transform infrared spectrometer. The results show that the flexural strength and compressive strength after 7 d and 28 d can be significantly improved by water-milled silica fume at 250 r?min^-1 for 20 min. Especially the early strength， which is up to 18.4% and 15.8% higher than the baseline group， respectively. Wet grinding can effectively reduce the agglomeration of silica fume， significantly improve the filling effect and pozzolanic activity of silica fume， and improve the mechanical properties of cement paste.