龙开口水电站碾压混凝土施工关键环节质量控制

Quality Control Measures in Key Construction Processes of Longkaikou RCC Dam

龙开口水电站工程所处河段气候干热、风大,在国内首次大规模使用白云岩作混凝土骨料,大坝碾压混凝土施工质量控制难度大。为此,在大坝碾压混凝土施工配合比、入仓方式、平仓与碾压、层间结合控制、变态混凝土施工等关键环节采取了一系列的质量控制措施。将砂中石粉含量控制在17%,同时控制微粉含量不小于5%;以自卸汽车直接入仓为主,配合满贯泄槽和胶带机入仓;利用数字化大坝系统监控混凝土碾压。上述控制措施的应用,实现了大仓面连续快速浇筑,保证了混凝土各项性能满足设计要求。

The Longkaikou Hydropower Station locates at a hot, dry and windy region, and the dolomite is abundantly used as concrete aggregate for the first time in China. The construction quality of RCC is difficult to control. A series of quality control measures are implemented in key construction processes of mix proportion determination, concrete transportation, spreading and leveling and compacted, interlayer bonding control and distorted concrete construction. The powder content of artificial sand is controlled at 17% and the content of micronized powder is not less than 5%. The concrete transportation to placement surface is mainly taken by trucks and supplemented by chute shafts and belt conveyors. The compaction of concrete is controlled by digital dam system. These measures ensure the rapid and continue large-surface concrete placement and the quality of concrete meeting design requirements.