砂岩石粉对砂浆力学性能及水化特性的影响

为解决机制砂生产过程中伴生的石粉再利用问题,研究砂岩石粉对砂浆力学性能的影响,并通过XRD、DSC-TG、SEM及MIP等测试技术,分析砂岩石粉对水泥砂浆水化产物、形貌及孔结构等的影响。结果表明:当石粉含量不超过11%时,随着砂岩石粉含量的增加,砂浆的力学性能逐渐提高,砂浆的孔隙率、中值孔径及平均孔径均降低,石粉可优化浆体的孔结构分布;砂岩石粉中的CaCO_3可与C_3A发生反应,反应产物为C_3A·CaCO_3·11H_2O;砂岩石粉的颗粒填充效应和化学活性是提高浆体力学性能的主要原因;成果可为砂岩机制砂混凝土的制备及石粉的再利用提供借鉴。

Effect of sandstone powder on strength and hydration of mortar

In order to solve the problem of stone powder reuse in the process of sand production,we study the influence of sandstone powder on mechanical properties of mortar.By means of XRD DSC-TG,SEM and MIP,we analyze the influence of sandstone powder on the morphology and pore structure of hydration products of cement mortar.The results show that the mechanical properties of the mortar increase with the increase of the content of sandstone powder when the content of stone powder does not exceed 11%.With the increase of the content of sandstone powder,the mechanical property of the mortar gradually improves,while the porosity,median pore diameter,maximum aperture and average pore diameter of the mortar reduce.It proves that the stone powder can optimize the distribution of the pore structure of the mortar.The CaCO3 of the sandstone powder can react with C3A,and the reaction product is C3A·CaCO3·11H2O.Particle filling effect and chemical activity of sandstone powder are the main reasons for the improvement of the mechanical property of slurry.The results may serve as reference for the preparation of sand concrete and reuse of stone powder.