硫酸盐侵蚀会严重影响混凝土梁体的使用性能,水灰比会影响混凝土在盐环境中的扩散系数,从而影响到硫酸盐环境下混凝土箱梁的挠度,施工过程中的水灰比控制是混凝土结构和构件的使用性能和使用寿命的基础.采用长期浸泡法对缩尺混凝土箱梁进行硫酸盐腐蚀试验,研究混凝土箱梁内部的硫酸盐扩散情况.采用三分点加载试验对浸泡试验梁施加荷载,研究荷载与硫酸盐腐蚀联合作用下的挠度变化情况.基于 Lee H等侵蚀深度预测理论模型,得到了SO42-扩散深度与水灰比的关系,结合力学分析得到硫酸盐环境下混凝土箱梁挠度与水灰比的关系,并与试验结果进行对比,最终得到符合混凝土承载力与耐久性要求的施工水灰比.研究结果表明:试验与理论计算值具有较高的吻合度,且当水灰比为 0.48 时,可以保证硫酸盐腐蚀环境中混凝土箱梁的耐久性.
Study on Water-cement Ratio of Concrete Construction Based on Deflection Analysis of Sulfate Corrosion Box Girder
The erosion effect of sulfate can seriously affect the performance of concrete beams,and the water cement ratio can affect the diffusion coefficient of concrete materials in salt environments,thereby affecting the deflection of concrete box beams in sulfate environments.The control of water cement ratio during construction is the foundation for the performance and service life of concrete structures and components.Sulfate corrosion test was conducted on scaled concrete box beams using long-term immersion method to study the diffusion of sulfate inside the concrete box beams.The three-point loading test was used to apply load to the immersion test beam,and the deflection changes under the combined action of load and sulfate corrosion were studied.Based on the Lee erosion depth prediction theoretical model,the relationship between the diffusion depth of SO42-and the water cement ratio was obtained.Combined with mechanical analysis,the relationship between the deflection of concrete box beams in sulfate environment and the water cement ratio was obtained,and compared with experimental results.Finally,a construction water cement ratio that meets the requirements of concrete bearing capacity and durability was obtained.The research results indicate that there is a high degree of agreement between the experimental and theoretical calculation values.When the water cement ratio is 0.48,it can ensure the durability of concrete box beams in sulfate corrosion environments.
sulfate attackdeflection of box girderconstruction water cement ratio
万方数据
维普
