基于徐州矿区煅烧煤矸石细集料活性的砂浆孔结构研究

 采用X射线衍射法(XRD)、压汞法(MIP)以及环境扫描电镜(SEM)分析方法，研究煤矸石细集料在不同煅烧温度下的活性，并对不同活性的煤矸石细集料水泥硬化砂浆的孔结构进行探讨，并进一步分析孔结构与砂浆强度之间的关系。试验结果研究表明：不同活性的煤矸石细集料，在水化初期可以与水泥水化产物发生不同程度的二次水化反应，煤矸石细集料活性会对水泥硬化砂浆的孔径分布和孔隙率产生一定影响。采用较高活性的煅烧煤矸石细集料，可以降低水泥硬化砂浆的孔隙率和优化孔径分布，且大于200 nm的有害孔明显减少，100，20 nm以下的无害孔和少害孔相应增加，水泥硬化砂浆的水化产物相应增多。煅烧煤矸石细集料的活性由低到高，可以使砂浆的孔隙得到细化，更能有效地改善砂浆的孔结构，降低其孔隙率，能够提高砂浆的强度。

Pore structure of fine aggregate mortar based on the activity of calcined coal gangue from Xuzhou mining area

The X-ray diffraction(XRD)，the mercury intrusion porosimetry(MIP) and the environmental scanning electron microscope(SEM) were used to study the activity of fine aggregate of coal gangue under different calcination temperatures and the pore structure of hardened cement mortar of fine aggregate. The relationship between the pore structure and the strength of cement mortar was analyzed. The fine aggregates of coal gangue of different activity had the different levels of secondary hydration reaction with the hydration products of cement in the early period of hydration. The activity of fine aggregate of coal gangue affected the pore size distribution and porosity of hardened cement mortar. A highly active fine aggregate of coal gangue reduced the porosity of hardened cement mortar and optimized the pore size distribution. The harmful holes greater than 200 nm decreased significantly and the less harm or harmless holes of 100，20 nm increased. The hydration products of hardened cement mortar increased accordingly. The activity of calcined fine aggregate of coal gangue from low to high refined the porosity of the mortar，improved effectively the pore structure of cement mortar，reduced its porosity，and improved the strength of the mortar.