煤矸石水泥复合体系需水性研究

Research on Water Repuirement of Gangue-cement Composites

具有火山灰活性的自燃煤矸石可以作为水泥混合材料使用,但增大自燃煤矸石掺量会引起水泥标准稠度需水量增大等问题。本课题通过对自燃煤矸石细度、颗粒级配、比表面积、孔径分布、表面形态的分析,研究自燃煤矸石水泥复合体系需水量的影响因素。试验分别掺加石灰石粉、矿渣、粉煤灰、硅灰四种矿物外加剂,研究矿物外加剂对自燃煤矸石水泥复合体系需水量的改善作用。研究发现,自燃煤矸石颗粒孔隙率较大、表面形态粗糙是造成自燃煤矸石水泥复合体系需水量大的主要原因;以单掺30wt%自燃煤矸石的煤矸石水泥复合体系的需水量为参照量,复掺5wt%硅灰可明显降低自燃煤矸石水泥复合体系需水量,体系标准稠度需水量降低约9.8%。

The coal gangue with the activity can be used as a cement admixture. However,increasing the dosage of coal gangue will cause the water requirement for normal consistency of cement paste increases and other problems. In this research,the author studied the issues of water requirement of cement which is caused by coal gangue by the test of gangue fineness,particle size distribution,specific surface area,pore size distribution and surface morphology. And the author studied the effect of water requirement of composite system caused by four kinds of mineral admixtures. These four kinds of mineral admixtures are limestone powder,slag,fly ash and silica fume. The study found that gangue particles＇ large porosity and roughness are the main factors that caused the increasing of water requirement of coal gangue-cement composite system. Establishing the water requirement of coal gangue-cement which is single doped30wt% coal gangue as a reference volume,composite admixture 5wt% silica fume can significantly reduce the water requirement of coal gangue-cement composite system. And the water requirement of the system decreased by about 9. 8%.