Experimental Research On Mechanical Performance Indexes Of Recycled Concrete

With the urbanization process of the whole world speeding up, a large number of construction wastes which is produced by the large-scale construction projects and the urban renewal is growing more and more, it has some negative impacts on the environment, and the abandoned concrete occupy a great part in the construction wastes, if the abandoned concrete only to be deal with landfill, a lot of land will be expropriated, and the pollution to the environment and social issues will be caused during the process of carrying and piling up. Therefore, it is necessary to recycle and reuse the abandoned concrete, however, the technology research of the recycled concrete is still in the initial stage at present in China, the research of the recycled concrete mechanical performances is scattered, the sophisticated technology and regulations are needed, so it is difficult to have abandoned concrete on a larger scale recycling.The influence of different water-binder ratio, different percentages of recycled aggregate and different percentages of fly ash to the mechanical performances of the recycled concrete are studied in this paper, and the conversion relationships between each two mechanical performance indexes are also studied. The water-binder ratio, the percentages of recycled aggregate and the percentages of fly ash are considered as the main factors in the test, and then the components of recycled concrete are set according to the different water-binder ,the different percentages of recycled aggregate and fly ash, and then the cubic compressive strength, the cubic tensile-splitting strength, the flexural strength and the elastic modulus are tested after 28days curing time, the influences of each factor to the indexes and their significant extents are studied by using the rank of significance analysis and the analysis of variances.The broken patterns of specimens are studied in this paper, the main causes leading to the destruction of the recycled concrete are studied. Based on the results of the tests, citing and counting the domestic and foreign test results, according to the conversion relationships of the ordinary concrete, using the nonlinear-regression analysis, the conversion relationships between each two mechanical performance indexes are established, it can be used as a reference to the research of the mechanical performance of recycled concrete in the future.