The Resistance To Chloride Ion Permeability And Durability Performance Analysis Of Manufactured-Sand Concrete Structures

With gradually reducing of useable natural sand in our country, the manufactured-sand will be inevitably selected as fine aggregate used in concrete. However the representation form of chlorine penetration resistance of manufactured-sand concrete under different test conditions and methods performs differently, then the analysis content of chloride diffusivity based on this is not consistent. With the related performance of anti-chloride corrosion ability of manufactured-sand concrete under conditions of accelerated electric field and immersion test, the anti-chlorine erosion tests of accelerated electric field and immersion have been done and correlational analyses have been promoted on the basis of different test conditions. So as the durability of manufactured-sand concrete under chloride environment.The main content and achievements of this paper are as follows:(1) The anti-chlorine erosion experiments of manufactured-sand concrete under accelerated electric field conditions have been launched and the effect of water-binder ratio, the combination of slag and fly ash, and the replacement rate of mechanism sand and coarse aggregate for anti-chlorine erosion ability of concrete has been studied. At the same time, the multi-factor model about electric flux and chloride ion diffusion coefficient data have been established and this paper has presented a correlative model of electric flux and chloride ion diffusion coefficient. The research shows the combination of slag and fly ash is supposed to be the dominating factor for anti-chlorine erosion ability of manufactured-sand concrete. In addition, the anti-chlorine erosion ability of manufactured-sand concrete increases with increasing slag when given the same content mineral admixture in manufactured-sand concrete.(2) Experiments are conducted to determine how water-binder ratio, the combination of slag and fly ash, and the replacement rate of mechanism sand and coarse aggregate will affect the apparent chloride diffusion coefficient under different immersed ages. A rapid analysis chloride diffusion coefficient based on double controlled lines was presented for determining the settings, and the multi-factor estimation model about the chloride diffusivity was set up. The research indicates that the combination of slag and fly ash is the chief factor which influence the anti-chlorine erosion ability of manufactured-sand concrete.(3) The correlation study of anti-chloride penetrating ability about immersion test and rapid chloride migration test has been conducted. Also, the correlation model has been developed,and there is a research finding that some linear relationship exist in immersion test and rapid chloride migration test.(4) Durability analysis and life prediction of manufactured-sand concrete under chloride environment have been developed based on different experimental methods. On the basis, the durability and lifespan of manufactured-sand concrete structure have been discussed, and the research indicates that the service life of concrete will be overestimated if the traditional computation model used, and the correction one has proved to be more grounded in reality than the traditional.