珊溪水库堆石坝面板混凝土防裂技术研究

Study on the anti crack technology of the slab for the concrete face rockfill dam of Sanxi Reservoir

珊溪水库混凝土面板堆石坝一期面板最大长度为 144m ,属国内一次性连续浇筑的最大长度 ,对普通混凝土来说 ,产生裂缝是不可避免的。但十二局施工科研所通过对珊溪水库面板混凝土防裂技术研究 ,增加了限制膨胀率e这个参数 ,即 2 81× 10 -4 ≤e≤ 6 73× 10 -4 ,有效地控制了收缩补偿和膨胀限制 ,从而避免或减少了由于面板混凝土收缩而引起的裂缝。经检验未发现裂缝 ,取得了预期的防裂效果。

The maximum length of the first stage face slab for the Sanxi concrete face rockfill dam is 144 m. Made by continuous pouring in a lump, the slab also is the longest in China. It is inevitable for normal concrete to produce cracks in such long slab. The Construction Scientific Institute of China Water Conservancy and Hydropower Engineering Bureau 12 studied the anti crack properties of concrete and put forward a parameter, that is, limited expansion rate 'e'. In the Sanxi concrete face rockfill dam, the adopted value of 'e' is 2 81×10 -4 ≤e≤6.73×10 -4 , which effectively controls the shrinkage and expansion of concrete and avoids or reduces cracks in face slab. After the completion of the Sanxi concrete face rockfill dam, no crack is found.