适用于-5℃环境的灌浆材料制备及其性能研究

Study on the Preparation and Properties of Cementitious Grouts at Negative Temperature(-5℃)

通过复掺硫铝酸盐水泥(CSA)、铝酸盐水泥(CAC)改进灌浆材料在负温环境下的性能,研究-5℃环境下CSA、CAC对灌浆材料流动性、凝结时间、抗压强度及竖向膨胀率的影响,结合X射线衍射(XRD)、扫描电镜(SEM)等手段表征浆体微观结构变化。结果表明,掺入CSA、CAC能显著提高普通硅酸盐水泥(OPC)灌浆材料早期强度,CAC增强效果优于CSA;但砂浆试件后期强度发展仍主要由OPC水化提供。随着CSA、CAC掺量增加,灌浆材料流动性及竖向膨胀率呈降低趋势。微观分析表明,CAC能明显促进水泥试件早期水化程度,进而生成更多的钙矾石及氢氧化钙;随着CAC掺量的增加,钙矾石长径比增大,其形貌由六角柱状转变为细针状。在-5℃环境中,灌浆材料最佳配比为:普通硅酸盐水泥,58%;硫铝酸盐水泥,8%;铝酸盐水泥,16%;二水石膏,9%;矿粉,9%。

Sulpho-aluminate cement(CSA)and aluminate cement(CAC)were used to improve the performance of the grouting material under a negative temperature environment.The influences of CSA and CAC on the fluidity,setting time,compressive strength and vertical expansion rate of grouting materials were studied.Phase composition and microstructure were also characterized with XRD and SEM.The results show that the addition of CSA and CAC significantly increased the early strength of grouting materials.Meanwhile,the influence of CAC was superior to that of CSA and later strength development of cement was mainly attributed to OPC hydration.Besides,ettringite and portlandite were the main hydration products.More hydration products were promoted by CAC,which results in the improvement of the early performance of grouting material.With the increase of CAC,the aspect ratio of ettringite increased and the morphology changed from hexagonal columnar to the fine needle.The optimum mixture proportion of grouting material was 58%OPC,8%CSA,16%CAC,9%gypsum,9%mineral powder.