聚羧酸类减水剂在水工混凝土中的应用研究

Study on Application of Poly-carboxylic Acid Water-reducing Agent to Hydraulic Structure Concrete

聚羧酸类减水剂是-种新型的高性能混凝土外加剂,在某大型水电站拱坝混凝土中进行了试验研究。与萘系减水剂相比,不仅具有碱含量低,表面张力小,增强效果好、高减水率等特点,而且还可降低混凝土收缩,延缓水泥水化峰值。与掺萘系减水剂的大坝混凝土相比,聚羧酸类减水剂有利于改善混凝土和易性,减少混凝土坍落度损失和含气量损失、降低混凝土早期绝热温升、提高混凝土的抗裂性指标。更适应工程建设对混凝土高强度、高性能及对混凝土工作保持性高的要求。

The poly-carboxylic acid water-reducing agent is a new type high-performance concrete admixture,which was studied and tested in arch dam concrete of a large hydropower project.As compared with the naphthalene series water-reducing agent,it is not only characterized by low alkali content,low surface tension,high reinforcing effect and high water reducing efficiency and also conducible to reducing concrete shrinkage and retarding cement hydration peak value.Compared with dam concrete mixed with the naphthalene series water- reducing agent, the poly - carboxylic acid water - reducing agent helps improve workability of concrete, reduce slump and air content losses of concrete, lower early - stage adiabatic temperature rise of concrete and improve crack resistance of concrete, thus meeting the requirements of engineering project construction for high strength, high performance and working sustainability of concrete.