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首页> 外文期刊>Hydrotechnical Construction >CONSTRUCTION OF DAMS FORMED FROM ROLLER-COMPACTED CONCRETE. ANALYSIS OF STATE OF THE ART AND PROSPECTS FOR DEVELOPMENT
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CONSTRUCTION OF DAMS FORMED FROM ROLLER-COMPACTED CONCRETE. ANALYSIS OF STATE OF THE ART AND PROSPECTS FOR DEVELOPMENT

机译：由辊压混凝土制成的DAMS的构造。现状分析和发展前景

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The search for effective methods of controlling temperature-induced cracking in concrete dams was initiated as early as the 1950s. The situation was found difficult, since this problem is directly associated with such important indicators as the completion date of construction, its cost, and labor outlays expended in concreting operations. Over the years, attempts to resolve the cracking problem by increasingly strengthening measures for temperature regulation have only resulted in further degradation of the above-noted indicators. Attempts to reduce exothermal warming of concrete by use of pozzuolanic additives, especially where it has been required to provide for impermeability and frost resistance of the concrete, have also failed to produce the required effect. The first successes appeared only after a principal change in the methods employed for concrete placement: dangerous cracks were successfully avoided in constructing the Alpa-Gera and Chivaira del Miniera (Italy), and Toktogul and Kurpsa Dams (USSR) owing to conversion to the layer-by-layer method of concrete placement with the maximum degree of mechanization in concreting operations. Use of low blocks (with a height of 0.5-0.75 m) and new approaches to sectioning of the dam (transverse joints have been installed without the use of traditional formwork) have made it possible to utilize a concrete-placement procedure similar to the procedure used to place earth fills. A more complete solution of the indicated problem was ultimately found on the basis of conversion to lean concrete mixes of stiff consistency, which submitted to compaction under vibratory rollers, i.e., just as earth structures are compacted. It is interesting to note that motivation for the search for new methods of concrete placement has gradually converted from a crack-control problem to a plane for development of a procedure that will make it possible to reduce significantly the cost and completion time of the construction of concrete dams and render them competitive with dams formed from local materials. Experience gained in recent years has demonstrated that this situation has created premises for successful use of roller-compacted concrete (RCC) in dam construction: significant reduction in concrete-placement times and appreciable simplification of concreting procedures make it possible to lower the construction cost of concrete dams so much that they are becoming more advantageous than rock-fill dams.
机译：早在1950年代就开始寻求有效的方法来控制温度引起的混凝土坝裂缝。人们发现这种情况很困难，因为这个问题与重要的指标直接相关，例如建筑的完工日期，成本和混凝土作业中的人工支出。多年来，通过越来越加强温度调节措施来解决裂纹问题的尝试仅导致上述指标的进一步退化。尝试通过使用火山灰添加剂来减少混凝土的放热升温，特别是在需要提供混凝土的抗渗性和抗冻性的地方，也未能产生所需的效果。最初的成功只有在混凝土浇筑方法发生重大变化之后才出现：成功改建了Alpa-Gera和Chivaira del Miniera（意大利）以及Toktogul和Kurpsa Dams（苏联）避免了危险的裂缝，这是由于改用了该层混凝土作业中机械化程度最高的混凝土浇筑的分层方法。使用低矮的砌块（高度为0.5-0.75 m）和采用新的水坝分段方法（在不使用传统模板的情况下安装了横缝）使利用类似于混凝土浇筑步骤的方法成为可能。用于放置填土。最终的解决方案是基于向坚硬稠度的贫混凝土混合物的转化中找到更完整的解决方案，该混合物在振动压路机下进行压实，即在夯实土方结构时进行压实。有趣的是，寻找新的混凝土浇筑方法的动机已经从裂缝控制问题逐渐转变为开发流程的平台，这将有可能显着降低施工成本和完工时间。混凝土水坝，使其与当地材料制成的水坝竞争。近年来获得的经验表明，这种情况为在大坝建设中成功使用碾压混凝土（RCC）创造了前提：显着减少混凝土浇筑时间并显着简化了浇筑程序，从而有可能降低混凝土的建造成本。混凝土水坝是如此之多，以至于它们变得比堆石坝更具优势。

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