Study on the impermeability for chloride ion and sulfate ion of non dispersible concrete under different erosion environments
Non-dispersible concrete in different erosion environments will be penetrated by erosion ions,which will seriously affect the durability of non-dispersible concrete.In this experiment,the resistance of non-dispersible concrete with different strength grades to erosion ion penetration in chloride solution,sulfate solution and composite salt solution was studied.Through the analysis of the influence of different slag content on its anti-erosion ion permeability,the coupling effect of Cl-and SO42-in the infiltration process is explored,and the pore characteristics of each sample at different erosion ages are tested by AutoPore IV 9500 mercury intrusion instrument.The results show that the ion concentration of C35 concrete is from 7%to 60%lower than that of C25 concrete at 5 mm and 30 mm away from the erosion surface.Under the same erosion environment,adding slag powder can significantly reduce the concentration of erosion ions in non-dispersible concrete.The pore composition in non-dispersible concrete is mainly mesoporous and microporous with diameter less than 50 nm.The addition of slag refines the pore structure,it means that the impermeability of non-dispersible concrete is significantly improved with the increase of its compressive strength grade,and the addition of slag powder makes the structure more compact,so as to effectively improve the impermeability of Cl-and SO42-of concrete.
non-dispersible concreteslag powderresist erosion ion penetrationpore structure
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