Mxi Proportion And Construction Technique Behaviors Of Rcc In Laboratory

Roller Compacted Concrete (RCC) is a kind of super-dry concrete which is placed in thin lift and completed by vibrating roller during the construction. This technique not only results in simplifying temperature control measures and shorting construction period, but being convenient to construction and a saving on cost. With the deep researches and engineering applications in twenty years, RCC dam technique has gone ahead by leaps and bounds in China and come up to or surpassed advanced world levels in dam type, dam height, volume of RCC and number of or RCC dams.The material compositions for RCC are substantially the same for the traditional concrete, but the mix proportions are quite different and in turn their behaviors. The first critical task is to select a mix proportion for RCC, which is possessed of workability for compaction and meets the requirements of design index. And the second is to test the properties of selected mix proportion such as physical and mechanical, durable and thermal.To have RCC meet the requirements of designed compaction parameters such as Vc value and density, besides mix proportion optimization, a job trial must be done to determine the degrees of influences of various items on RCC compaction quality such as the mechanical property of vibrating roller, quality control measures, the allowable period of time and shear strength between layers.In this paper, based on the design of RCC in Bao Zhusi hydropower project, a lot of tests were carried out in order to determine an applicable mix proportion which was met to the requirements of design and construction for the project. To the limited conditions at dam site, normally much time, more labors and cost would be needed for carrying the necessary tests and even so test progresses usually could not catch the design requirements. Therefore, laboratory tests were used to replace site tests for determining site compaction parameters of RCC based on selected mix proportions herein, which was the first time to try in China.Through the mathematical mode built according to the construction technique modeling tests and refer'to engineering experiences at home andabroad, a mix proportion of RCC and corresponding construction technique parameters to meet the requirements of design and construction were proposed. In this way, test period of time was shortened and teat cost saved. This method is of practical and meaningful for Lin Hekou RCC dam construction and other similar projects.