两种改性剂对注浆材料流变性能的影响

Effects of Two Modifiers on Rheological Properties of Grouting Materials

为了提高加固、防渗堵漏等工程的注浆质量,往往需要添加改性剂来调控注浆材料的流变性能。本文研究了两种改性剂(早强型注浆改性剂SX-ZJ-Z和高强型注浆改性剂SX-ZJ-G)对注浆材料流变性能的影响,测试了它们在不同掺量(10%和20%,质量分数)以及不同水胶比(W/B=0.25、0.30、0.35和0.40)下的凝结时间、流动度、塑性黏度和屈服应力,并分析了Bingham和Modified Bingham模型对注浆材料流变曲线的拟合度。结果表明:添加SX-ZJ-G能显著延长注浆材料的凝结时间,而添加SX-ZJ-Z会缩短注浆材料的凝结时间;SX-ZJ-G掺入后发挥“滚珠”效应,能大幅提高注浆材料的流动性,但是添加SZ-ZJ-Z对注浆材料的流动性几乎没影响。添加改性剂使水泥浆体由牛顿流体转变为屈服应力流体,呈现出非线性的剪切应力曲线,Modified Bingham模型较Bingham模型有更好的拟合效果。在W/B=0.30、0.35和0.40时,掺入SX-ZJ-Z对注浆材料的塑性黏度和屈服应力影响不大;SX-ZJ-G的掺入极大地降低了水泥浆体的塑性黏度和屈服应力,降幅可达89%以上,改善了注浆材料的流变性能。

In order to improve the grouting quality of reinforcement,anti-seepage plugging and other projects,it is necessary to adjust rheological properties of grouting materials by adding modifiers.The effects of two modifiers(early strength grouting modifier SX-ZJ-Z and high strength grouting modifier SX-ZJ-G)on rheological properties of grouting materials were studied,and their setting time,fluidity,plastic viscosity and yield stress were tested at different content(10%and 20%,mass fraction)and water-to-binder ratios(W/B=0.25,0.30,0.35 and 0.40),and the degree of fitting of Bingham model and Modified Bingham model to their rheological curves was analyzed.The results show that the addition of SX-ZJ-G significantly prolonges coagulation time of grouting materials,while the addition of SX-ZJ-Z shortenes setting time of grouting materials.The addition of SX-ZJ-G exerts the“ball”effect and greatly improves fluidity of grouting materials,but the addition of SZ-ZJ-Z has almost no effect on fluidity of grouting materials.The addition of modifier changes the cement slurry from Newtonian fluid to yield-stress-fluid,showing a nonlinear shear stress curve,and Modified Bingham model had a good fitting effect compared with the Bingham model.When W/B=0.30,0.35 and 0.40,the addition of SX-ZJ-Z has little effect on plastic viscosity and yield stress of grouting materials.The addition of SX-ZJ-G greatly reduces plastic viscosity and yield stress of cement slurry by more than 90%,and improves rheological properties of grouting materials.