In order to accelerate the application of magnesium oxide (MgO) expanding admixture in roller compacted concrete (RCC), aiming at common three-grading RCC used in water conservancy and hydropower engineering, the autoclave expansion of mortar specimens and the compressive strength of the autoclaved mortar specimens were studied by means of autoclave test and compressive strength test. Results showed that the balanced MgO content in RCC, which cannot be determined by the MgO content corresponding to 0.5% autoclave expansion rate of mortar specimens or the inflection point of the curve of autoclave expansion changing with MgO content like normal concrete, should be determined by the MgO content corresponding to the inflection point of the curve that compressive strength of autoclaved mortar specimens changes with MgO content to ensure long-term safe operation of RCC dams.

中文翻译：

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碾压混凝土中氧化镁平衡含量的研究

为了加快氧化镁（MgO）膨胀剂在碾压混凝土（RCC）中的应用，针对水利水电工程中常用的三级RCC，砂浆试样的高压釜膨胀和高压釜的抗压强度通过高压釜试验和抗压强度试验研究了砂浆试样。结果表明，RCC中平衡的MgO含量不能像普通混凝土一样，通过0.5％的砂浆试样高压釜膨胀率所对应的MgO含量或高压釜膨胀曲线的拐点随MgO含量的变化而确定，