碾压混凝土配合比参数优化是保障筑坝安全的重要技术措施。依托高原区碾压混凝土筑坝工程,重点探讨了外加剂掺量和粉煤灰品质在碾压混凝土配合比设计中的控制机理,拟合了不同工况下碾压混凝土胶水比与抗压强度的关系曲线。结果表明:在不影响碾压混凝土品质的情况下,提高外加剂掺量可以有效降低胶凝材料的用量;粉煤灰的等级对混凝土用水量有很大的影响;碾压混凝土胶水比与抗压强度有较好的线性相关性,其各龄期抗压强度发展系数先增长较快,后增速放缓并趋于平稳。该设计经验可为类似工程的碾压混凝土配合比优化设计提供参考。

Optimizing the mix ratio of RCC (rolled compacted concrete) is an important technical measure to protect dam safety. With RCC dam project in cold area as an example, we discuss the dosage of admixture and quality of fly ash affecting the mix proportion design, and obtain the fitted relationship curves between RCC binder-water ratio and compressive strength under different working conditions. Results show that increasing the dosage of admixture could effectively reduce the plastic material dosage without affecting the quality of roller compacted concrete; fly ash of different grades has great effect on the water use of concrete; the water-binder ratio has good linear correlation with compressive strength. The variation of compressive strength development coefficient leveled off after the first increase.