南水北调工程江苏境内泵站混凝土配合比试验

Research on concrete mix proportion for pump station construction within Jiangsu Province for South-North Water Diversion Project

探讨了粉煤灰、高效减水剂及引气剂掺量对混凝土性能的影响,为南水北调东线工程泵站混凝土提供施工配合比。通过掺入粉煤灰、高效减水剂及引气剂,配制了不同强度等级的混凝土,研究了C20、C25、C30等3种不同强度等级混凝土力学性能、耐久性能及体积稳定性,并用扫描电镜法(SEM)表征混凝土界面过渡区。研究表明:掺入粉煤灰、高效减水剂及引气剂后,混凝土立方体抗压强度均达到设计指标;在较高水胶比条件下,混凝土抗压、抗拉强度、弹性模量、抗渗性能均随着粉煤灰掺量增加而略有提高,同时掺入粉煤灰改善了混凝土界面过渡区。粉煤灰、高效减水剂及引气剂掺量分别不超过胶凝材料用量的30%、1%、0.015%时,所配制的C20、C25、C30混凝土满足南水北调工程江苏境内泵站混凝土施工要求。

The authors discuss the effects of different mixing amounts of fly ash, high rate water reducing agent and air-entraining agent on the properties of concrete. In order to study the concrete mix proportion for pump station construction of the east route of South-North Water Diversion Project, fly ash, water reducing agent and air-en- training agent were used to make concrete of C20, C30 and C30 with different strength. The mechanical properties, durability and stability of these three grades of concrete were studied, including characterization of concrete interra- cial transition zone by scanning electron microscopy （SEM）. The results of study show that compressive strength of concrete conforms to design specification after mixing of fly ash, high rate water reducing agent and air-entraining agent. At relatively high water-cement ratio, with increasing of fly ash content, the compressive strength, tensile strength, elastic modulus, impermeability of concrete increase slightly. Mixing of fly ash also improve the concrete interfacial transition zone. When the mixing percentages of fly ash, high rate water reducing agent and air-entrain- ing agent do not exceed 30%, 1% and 0.015% of the amount of cementing materials respectively, the manufac- tured concrete of C20, C25 and C30 can satisfy the requirements of pump station construction within Jiangsu Prov- ince for South-North Water Diversion Project.