高碱活性砂岩骨料在混凝土防渗面板中的应用

Application of High Alkali Active Sandstone Aggregates in Concrete Impervious Face Slab

混凝土骨料的碱活性对混凝土的危害极大,严重威胁混凝土工程的安全运行。洪屏抽水蓄能电站工程上水库防渗面板采用砂岩作为混凝土骨料,根据试验检测该砂岩骨料具有较强的碱活性。为确保工程安全运行,在有效抑制骨料碱活性的同时得到各项性能均满足防渗面板要求的混凝土,分别对粉煤灰、矿渣灰、硅灰以及复合掺加粉煤灰和硅灰的抑制效果以及混凝土性能进行试验研究。研究显示,上述掺合料均可以达到有效抑制骨料碱活性的作用,但不同的掺合料对混凝土的性能存在不同的影响。通过混凝土配合比优化设计最终选定本工程采用的混凝土配合比,根据试验检测混凝土各项性能满足设计和规范要求,成功实现了高碱活性砂岩骨料在混凝土防渗面板中的应用。

The alkali activity of concrete aggregates has great harm to the concrete, which seriously threatens the safety operation of the concrete project. The sandstones are used as concrete aggregates to pouring impervious face slabs in Hongping Pumped Storage project. The experiments show that the sandstone aggregates have strong alkali activity. To ensure the safe operation of the project, and effectively inhibit aggregate alkali activity, the performances of mixed concrete meet the needs for impervious face slab. The effects of mixed fly ash, slag, and silica fume on concrete performances are investigated experimentally. Research shows that the admixtures can effectively suppress the role of aggregate alkali activity, and different blending material performances have some effect on concrete performances. Through the concrete match ratio optimization design, ultimately reasonable match ratio of concrete materials is determined. According to test results of the properties of concrete, the successful implementation of the application of high alkali reactivity of sandstone aggregate in concrete impermeable panel is performed.