“双掺”技术在三峡永久船闸输水系统混凝土中的作用

The Role of the Additives in the Concrete of the Permanent Shiplock Water Conveyance Systemin the Three Gorges Project

“双掺”技术已在水工混凝土中普遍应用，但在过水建筑物混凝土中较少采用。通过三峡工程永久船闸地下输水系统混凝土配合比试验研究，讨论混凝土配合比中粉煤灰、高效减水剂、引水剂联掺对地下工程衬砌混凝土的改性作用，提出在控制水灰比和粉煤灰掺量的情况下，“双掺”技术对水工隧洞混凝土衬砌工程也具有良好的技术经济效益。

Additives have been widely used in hydraulic structure concrete, but not in overflow structure concrete. This paper has a discussion on the effect of using combined flyash, high-effective water-reducing agent and air-entraining agent on improving properties of the underground structure lining concrete on the basis of the permanent shiplock water conveyance system concrete mix proportion study in the Three Gorges Project, and justifies the sound technical and economic benefits of applying the combined additives in the hydraulic tunnel concrete lining works provided that the water-cement ratio and quantity of flyash additive are properly controlled.