无砂混凝土在高地下水位渠道边坡衬砌中的应用

Application of Sand-free Concrete in Channel Slope Lining with High Groundwater Level

为探究无砂混凝土在高地下水位渠道边坡衬砌中的适用性,以南水北调工程某页岩渠坡段衬砌施工为例,对不同配合比下的无砂混凝土进行了有效孔隙率、强度和不同水头下的渗透试验。结果表明:粗粒径含量越多,有效孔隙率越大,连续级配的有效孔隙率低于单粒径级配;连续级配的强度值明显大于单粒级配的强度,骨料越细,强度越高;随着水头的增大,无砂混凝土的渗透系数呈幂函数型增长,连续级配的渗透系数明显小于单粒级配渗透系数;通过配比优化,最终确定了现场的最佳施工配比为:水灰比0.45,灰骨比1∶6,水∶水泥∶石子=135.5∶301∶1806。分析结果可为类似工程的设计施工提供参考。

In order to explore the applicability of sand-free concrete in the lining of high groundwater channel slopes,the lining construction of a shale rock slope section of the South-to-North Water Transfer Project takes the effective porosity,strength and difference of the sand-free concrete under different mixing ratios. Penetration test under the water head. The results show that the larger the coarse particle size, the larger the effective porosity, the lower the effective porosity of the continuous gradation is than the single particle size gradation;the strength of the continuous grading is significantly greater than the strength of the single grading, the finer the aggregate The higher the strength;with the increase of the water head, the permeability coefficient of the sand-free concrete increases with a power function, and the permeability coefficient of the continuous gradation is significantly smaller than that of the single-grain gradation. Through the optimization of the ratio, the most The optimum construction ratio is: water cement ratio 0.45, gray bone ratio 1:6, water: cement: stone = 135.5:301:1806. The analysis results can provide reference for the design and construction of similar projects.