龙滩大坝碾压混凝土层间结合质量识别标准

Quality identifying standard for RCC interlayer properties of Longtan Dam

应用龙滩工程的原材料,研究了两种缓凝高效减水剂中缓凝组分用量在不同试验条件下对碾压混凝土凝结时间的影响规律,建立了碾压混凝土层间允许暴露时间的确定准则和现场碾压混凝土凝结状态的快速评定方法。提出了适合于龙滩工程碾压混凝土层间结合“热缝”、“温缝”、“冷缝”的识别标准。

Using the raw materials from Longtan Hydropower Project, a series of tests have been carried out to try to determine the relationships between the different dosages of retardation compound when combined with a high efficient water reducing admixture and the initial set of the RCC mix, especially, the initial set patterns of RCC mix with different dosage of retardation composition under different test conditions. From this it was possible to identify a method for determining the allowable exposure time for RCC interlayer and a quick method for assessing, on site, the initial set of the RCC mix was recognized and established. Finally, a very practical standard for the identification of hot, warm and cold joints is proposed and suitable for the interlayer properties of Longtan RCC mix.