低热高性能混凝土的研究及应用

Study on low- hot and high- performance concrete test and application in hydropower project

大体积混凝土防裂问题是当今水电工程建设中面临的主要技术难题。本文结合光照、董箐、石垭子水电站工程，采用三低一高的混凝土配合比设计方法，通过大量的室内外试验研究，配制低热高性能混凝土，并成功应用在水电工程碾压及常态混凝土中。粉煤灰掺量在碾压混凝土中达70％～80％，在常态混凝土中可提高到40％一70％。低热高性能混凝土的工作性能以及热学、耐久性能、抗裂性均有较大幅度的改善，具有显著的技术经济效益、环保效益和社会效益，可在水电工程中推广应用。

The crack problem of hydrostructure concrete is a main technical difficulty in the construction of hydro- power projects at the present time. To solve crack problem of hydrostructure concrete, the first is to optimize the hydrostructure concrete proportioning and solve the adiabatic rise of temperature and control of temperature. The concrete proportioning of ＂three low and one high＂ is adopted in the design of Guangzhao, Dongqing and Shiyazi hydropower projects described in the paper. Through test and research in the field, low - hot and high - performance concrete is mixed, which is successfully applied to RCC and normal concrete of hydropower project. The application and study show that the content of fly ash can account for 70% - 80% in RCC and 40% ~ 70% in normal concrete if the concrete with no special requirement by using normal Portland cement and Grade II fly ash with low -hot and high- performance concrete mixed by high -performance water- reducing admixture. In this way, the concrete property, heat and lasting quality will be largely improved and the anti - crack property can be increased. At the same time, low -hot and high -performance concrete has evident economic, environmental and social benefits, so it is valuable for popularizing in hydropower project.