黄河上游水电站抗冲磨混凝土试验研究

Experimental Study on Anti⁃Abrasion Concrete of Hydropower Stations in the Upper Yellow River

为解决黄河上游水电站建设中抗冲磨混凝土收缩和开裂等问题,对黄河上游已建工程进行调查分析,结果没有发现泄水建筑物抗冲蚀层混凝土渗透侵蚀和冻融破坏现象,但开裂和脱空现象比较严重。针对存在的问题,结合某工程混凝土配合比设计项目,开展了抗冲磨混凝土试验研究,在中热水泥、粉煤灰和硅粉组成的复合材料基础上,通过掺入聚羧酸减水剂、聚丙烯纤维和减缩剂等进行改性研究。结果表明:改性后混凝土干缩率大幅度降低、抗裂性显著提高,可防止或减缓黄河上游地区水电工程的抗冲磨混凝土收缩开裂,改善混凝土结构耐久性。

In order to solve the problems of shrinkage and cracking of abrasion resistant concrete in the construction of hydropower stations in the upper Yellow River,the existing projects in the upper Yellow River were investigated and analyzed.No seepage erosion and freeze⁃thaw damage of the erosion resistant concrete of the discharge structures were found,but the cracking and void phenomena were serious.In view of the existing problems,combined with the concrete mix proportion design project of a project,the anti⁃abrasion concrete test was carried out.On the basis of composite materials composed of medium heat cement,fly ash and silica fume,the modification research was carried out by adding polycarboxylate water reducer,polypropylene fiber and shrinkage reducing agent.The results show that the dry shrinkage rate of the modified concrete is greatly reduced and the crack resistance is significantly improved,which can prevent or slow down the shrinkage crack⁃ing of anti⁃abrasion concrete of hydropower projects on the upper Yellow River and improve the durability of concrete structure.