洪家渡水电站面板混凝土防裂措施研究及其应用

通过对洪家渡水电站面板堆石坝面板混凝土的原材料、配合比、施工工艺以及结构等方面进行的防裂措施研究,推荐选用了合适的混凝土水胶比和较大掺量的优质粉煤灰;水泥选用自身体积收缩小的品种,掺用补偿收缩材料以及聚丙烯纤维;施工上尽可能降低坍落度,加强养护;结构上研究了面板的合理配筋率和配筋位置,并采取降低对面板混凝土的约束等措施.实践证明,取得了很好的防裂效果.

Application and research of crack-resistant measures for face slab concrete of dam for Hongjiadu Hydropower Station

Experimental study is made on the crack-resistant measures for the concrete face slab of the dam for Hongjiadu Hydropower Station in aspects of the raw materials, mix proportions, construction technology and the structures ; from which some measures are recommended, such as the proper water-cement ratio ; larger admixing amount of high quality flyash ; selection of the cement with low shrinkage ratio; adding the shrinkage-compensating materials and polypropylene fiber; lowering the slump of concrete to the possible extent and strengthening the curing of concrete during construction ; meanwhile, studying the reasonable reinforcement ratio and the locations to be reinforced and lowering the restriction on the face slab structurally, etc. It is practically demonstrated that better crack-resistant effect has been obtained from the measures hereinabove.