固废复合材料灌浆料复合试验设计、力学性能及微观结构分析

Composite Experiments Design,Mechanical Properties and Microstructure Analysis of Solid Waste Composite Grouting Material

为了提高粉煤灰、矿渣、铁尾矿砂和机制砂等固废的利用率,制备早强、微膨胀的高强灌浆料,本文通过复配普通硅酸盐水泥和硫铝酸盐水泥,以及设计石英砂-铁尾矿砂-机制砂的三元复合体系和正交试验的方式分析了在固废复合材料共同作用下灌浆料的力学性能和微观结构。试验结果表明,普通硅酸盐水泥和硫铝酸盐水泥最优质量比为4∶1,石英砂、铁尾矿砂、石灰石机制砂的最优质量配合比为7∶1∶2,正交试验4种因素对灌浆料试件强度影响程度由大到小为水胶比、粉煤灰掺量、胶砂比和矿渣掺量,通过极差分析得到最佳因素水平组合为水胶比为0.33、胶砂比为1.0∶1.2、粉煤灰掺量和矿渣掺量分别为6%和10%(质量分数)。通过XRD、SEM分析发现,C-S-H凝胶的密实程度会影响灌浆料试件的强度,水胶比对钙矾石物相有影响,钙矾石和六水铝酸三钙能提高试件的早期强度。

In order to improve the utilization rate of solid wastes such as fly ash,slag,iron tailing sand and manufactured sand and prepare early strength and slightly expansive high-strength grouting material,the mechanical properties and microstructure of grouting materials were analyzed under the joint action of solid waste composite materials by mixing ordinary Portland cement and sulphoaluminate cement,designing the ternary composite system of quartz sand,iron tailing sand and manufactured and orthogonal test.The test results show that the optimal mass mix ratio of ordinary Portland cement and sulphoaluminate cement is 4∶1,the optimal mass mix ratio of quartz sand,iron tailings sand,limestone manufactured sand is 7∶1∶2,and the influence degree of four factors on strength of grouting materials from large to small in the orthogonal test is water binder ratio,fly ash content,binder sand ratio and slag content.Through range analysis,the optimal factor level combination is water binder ratio is 0.33,binder sand ratio is 1.0∶1.2,and the fly ash content and slag content are 6%and 10%(mass fraction),respectively.Through the analysis of XRD and SEM,it is found that the density of C-S-H gel will affect the strength of grouting material.The water binder ratio has an effect on the phase of ettringite,and ettringite and tricalcium aluminate hexahydrate can improve the early strength of specimens.