铜街子水电站砼施工配合比选择

Selection of Mix Proportion in the Concrete Construction at Tongjiezi Hydropower Station

铜街子水电站系国家“七五”重点工程项目,砼量约270万m^3。砼配合比选择,运用正交试验及统计分析方法进行优选,并采用“双掺”技术和碾压砼,砼在使用细沙的不利条件下,将用水量降至90kg/m^3左右,水泥用量降至65kg/m^3。对已浇筑的200多万m^3砼质量抽检结果表明:各种标号砼强度保证率均达到90％以上;强度离差系数属一般和良好级水平;耐久性指标合格率在90％以上,超过“水工砼施工规范”的质量要求,取得了显著的技术经济效果。

Tongjiezi Hydropower Station is one of the key project of '7th five-year plan program of our country. The concrete mix proportion was optimated by orthogonal tests and statistical analysis method . 'Double-admix 'techniques and RCC were adopted. With fine sand,water content of concrete is reduced to about 90 kg/m3 and cement content is reduced to 65kg/m3. The sampling inspection to the quality of 20 million m3 poured concrete shows that guaranteed efficiency of concrete with verious strengths achieved to over 90%; dispersion coefficient for strength ranges from normal to good;the qualification ratio of durability index is up to 90%, which meets the quality requirement of ' Concrete Construction Specification of Hydraulic Structures',and obtains notable technical and ecnonmical results.