隧道溶腔填充泡沫混凝土的防水性能及细观特征

Waterproof Performance and Mesoscopic Characteristics of Foam Concrete for Tunnel Cavity Filling

为研究不同憎水剂对隧道溶腔填充泡沫混凝土防水性能的影响,通过单掺甲基硅酸钠、纤维素、硬脂酸钙、硅氧烷、渗透结晶型活性硅五种憎水剂,对泡沫混凝土的流动度、吸水率和力学性能展开试验,并采用CT(Computed Tomography)测试技术及图像分析软件Avizo分析单掺不同憎水剂对泡沫混凝土孔隙结构的影响。研究结果表明:除甲基硅酸钠外,其他四种憎水剂与泡沫的兼容性较好,流动度均满足技术规程要求;单掺纤维素、硬脂酸钙、硅氧烷和渗透结晶型活性硅均可提高泡沫混凝土的干密度与抗压强度,泡沫混凝土的防水性能、孔隙结构和连通性能也得到改善,其中单掺硅氧烷防水效果最好。

In order to study the influence of different water repellents on the waterproof performance of foam concrete for tunnel cavity filling,five kinds of water repellents,namely sodium methylsilicate,cellulose,calcium stearate,siloxane,and permeable crystalline active silicon,were added alone to foam concrete to conduct an experimental study on the fluidity,water absorption rate and mechanical properties of foam concrete.CT(Computed Tomography)test technology and image analysis software Avizo were used to analyze the influence of different water repellents on the pore structure of foam concrete.The research results show that,the compatibility between the other four water repellents and foam is good except sodium methylsilicate,and the fluidity meets the requirements of technical regulations.The dry density and compressive strength of foam concrete can be improved by adding cellulose,calcium stearate,siloxane,and permeable crystalline active silicon alone.The waterproof performance,pore structure and connectivity of foam concrete have also been improved,and the waterproof effect of siloxane alone is the best.