Research Of Influencing Factor Between Concrete Durability And Pore Structure

Nowadays, air entraining, mineral admixture and additive have been main measure to improve the concrete frost resistance and impermeability. Through manipulating the air content of mixture to control concrete frost resistance is the universal method in projects, but the study on the effect of concrete pore structure change after air entraining to the concrete frost resistance and impermeability is few, the study on the effect of mineral additive to concrete pore structure and durability is even fewer, so carry on this aspect research has significant meaning. This paper mainly study the effect of mineral additive to concrete pore structure, mechanical performance, frost resistance and impermeability, and discuss the relationship of pore structure and concrete performance.Using mercury intrusion method to measure the parameter of limestone pore structure system, including total porosity, most probable aperture, mean radius and so on, and discussing the relationship between pore structure and concrete frost resistance, anti-chloride ion diffusion, mechanical performance.The result indicated that, mix the mineral mixture of fly ash, flag into concrete can optimize the concrete pore structure, improve the concrete compressive strength and impermeability, and along with the age increment the improvement become more obviously; After saturated freezing and thawing, the concrete pore structure changed apparently, total porosity increased, macro porous quantity rapid increased, small pore quantity reduced, mean radius and most probable aperture increased; and the more saturated degree, the more obviously destructive effect. Mix mineral material can improve the concrete frost resistance ability, and the effect of compound mineral mixture surpassing solely mineral mixture.Mix mineral additive into concrete has great effect on the pore structure, especially the addition of sodium sulfate coarsening the pore structure enormously, and increase the total porosity. After mixing sodium sulfate, the chloride ion diffusion coefficient of air entraining concrete increased, impermeability reduced; but mixing sodium nitrite and sodium chloride can...