基于防水性能设计的湿喷混凝土衬砌结构优化研究

为提升喷射混凝土衬砌结构的防水能力,制备C50湿喷混凝土,建立纯湿喷混凝土衬砌结构作为对照组;选用3种防水膜(丙烯酸盐乳液、胶体乳液、水性聚脲)和3种防水砂浆(丙乳砂浆、胶乳砂浆、高强砂浆)作为防水层,将防水层设置在基准衬砌结构的迎水面、中部、背水面建立不同的组合衬砌结构型式,通过抗渗性试验和电通量测试,对各衬砌结构型式进行防水性能评价。结果表明,设置防水层可显著提升湿喷混凝土衬砌结构的防水性能;水性聚脲防水膜的防水性能优于丙烯酸盐防水膜和胶体乳液防水膜;丙乳砂浆和胶乳砂浆的防水性能均优于高强砂浆;防水层设计部位中,与湿喷混凝土组合衬砌结构的防水能力由大到小依次为迎水面中部背水面。

Structure Optimization of Wet-mix Shotcrete Lining Based on Waterproof Performance

To improve the waterproof ability of shotcrete lining structure, C50 wet-mix shotcrete as the unique material was made to establish a lining structure. Three kinds of waterproof membranes and three sorts of waterproof mortars were chosen for the waterproof layer. The waterproof membranes included acrylate emulsion, colloidal emulsion and waterborne polyuria. The waterproof mortars included acrylate emulsion mortar, colloidal emulsion mortar and high strength silica fume mortar. The lining structures were established when the waterproof layer was respectively set in the position of upstream face, middle part, downstream face. Evaluation of waterproof ability of lining structures were done by the tests of impermeability and electric flux. The results indicate that setting a waterproof layer can obviously improve the waterproof ability of wet-mix shotcrete lining structure. During the materials used in the waterproof layer, waterborne polyuria membrane is better than acrylate emulsion membrane or colloidal emulsion membrane. The acrylate emulsion mortar and colloidal emulsion mortar are both superior to high strength silica fume mortar. The waterproof ability of wet-mix shotcrete lining structure varies with the positions of waterproof layer, which has an effect sequence as follows: upstream face, then middle part and downstream face.