膨胀复合浆液的物理力学性能试验研究

目前普通硅酸盐水泥浆液是水利工程中最常用的注浆加固材料，针对其存在流动性差、析水率高、结石率低、结石体强度低、抗渗性能差等问题，采用单因素控制变量法和正交试验法，对制备的不同配合比的水泥基膨胀复合浆液进行黏度、密度以及结石体力学性能试验。试验结果表明:掺加粉煤灰可以增加浆液的和易性和流动性；掺加膨润土可以提高浆液的结石率和稳定性，同时降低浆液的析水率；掺加粉煤灰和膨润土的浆液流动性和结石率性能都有所改善，但是前期结石体强度较低，而后期强度主要靠粉煤灰的水化作用进行补充；水泥浆液掺加适量的膨胀剂对结石体的膨胀影响较大，并且可以提高结石体的抗渗性能。合理选择和控制粉煤灰、膨润土和膨胀剂掺量，可以明显改善和提高注浆效果。

Experimental study on physical and mechanical properties of expanded composite slurry

At present, ordinary Portland cement slurry is the common grouting reinforcement material in water conservancy engineering. In view of its poor fluidity, high drainage rate, low stone rate as well as its low strength and poor permeability performance problems, based on the preparation of different mixing ratios of cement-based expanded composite slurry, we adopted the single factor controlling variable method and the orthogonal experiment method to test the viscosity, density and mechanical performance of stone body. The experiment results reflect that adding fly ash could increase the workability and fluidity of slurry, and the bentonite could improve the stone rate of grouting and slurry stability. At the same time, bentonite also could reduce the drainage rate and slurry fluidity. The slurry mixed with bentonite and fly ash got improvement with its fluidity and stone rate, but the stone body strength was poor in the early stage. In the later stage, its strength was mainly supplemented by the hydration of fly ash. Cement slurry mixed with appropriate expansion agent had a great influence on the expansion of the stone body and could also improve the anti-permeability of the stone body. Consequently, reasonable selection and control of fly ash, bentonite and expansive agent can obviously improve the grouting effect.