三峡工程二阶段混凝土采用掺外加剂、粉煤灰和低水灰比的“两掺一低”技术措施,即在混凝土配合比设计及生产中,采用国标级粉煤灰同缓凝高效减水剂与引气剂联掺,以降低混凝土单位用水量,提高混凝土和易性,并坚持低水胶比设计,减少混凝土内部缺陷,进而提高混凝土多项技术性能。三 The second phase of the Three Gorges Project adopts “two admixtures and one low” technical measures of admixture admixture, fly ash and low water-cement ratio. In the concrete mix design and production, Blending agent with air entraining agent to reduce water consumption per unit of concrete, improve the workability of concrete, and adhere to the design of low water-cement ratio to reduce internal defects in concrete, thereby enhancing a number of technical performance of concrete. three