微膨胀混凝土在预制拼装箱梁湿接缝中的应用研究

Application Study on the Micro Expansion Concrete in the Wet Joint of Prefabricated Box Girder

混凝土表面泛碱生成的白色胶凝物质在潮湿环境下吸水膨胀,造成混凝土结构从内部胀裂,甚至破坏。预制拼装箱梁湿接缝处常出现表面泛碱质量通病,通常采用微膨胀混凝土进行预防泛碱质量通病。通过对采用微膨胀混凝土浇筑的预制拼装箱梁湿接缝和采用普通混凝土浇筑的预制拼装箱梁湿接缝分别进行收缩变形监测和外观检查,分析微膨胀混凝土对预制箱梁湿接缝泛碱质量通病预防程度。

The white cementitious material on the surface of concrete expands by absorbing water under the humid environment,which causes the concrete structure to expand and crack from the inside,even to destroy.The common quality defects of the surface efflorescence often appear at the wet joint of the prefabricated box girder,and the micro expansion concrete is usually used to prevent the common quality defects of the efflorescence.Based on the shrinkage deformation monitoring and appearance inspection of the wet joint of the prefabricated box girder cast by micro expansion concrete and the wet joint of the prefabricated box girder cast by ordinary concrete,the prevention degree of the common quality problems of the wet joint of the prefabricated box girder cast by micro expansion concrete is analyzed.