Research On Chloride Ion Permeability And Reinforcement Corrosion Of Alkali Activated Slag Concrete

Alkali activated slag concrete is a kind of energy-saving and environment-friendly building materials. It has excellent physical mechanical properties and durability. The correlation theory of Alkali activated slag concrete has became matured day after day. The research on Chloride ion permeability and reinforcement corrosion of Alkali activated slag concrete is very little. The research is important to promotion of Alkali activated slag concrete in the base of reinforced concrete and prestressed concrete projects in the application.The special surface of slag, alkaline kind, alkali content, modulus of water glass and mineral admixtures was found to affect the Chloride ion permeability and reinforcement corrosion of Alkali activated slag concrete. In this paper they were studied by the way of the rapid chloride permeability test (ASTM 1202) and wet and dry cycle. And the relationship between the pore structure, interface features and chloride ion permeability, the reinforcement corrosion was studied. The result shows:①When the solution to slag ratio is from 0.43 to 0.53, the coulombs passed concrete in 6hrs increased with the ratio increased in the same conditions, the Chloride ion permeability and reinforcement corrosion of Alkali activated slag concrete activated with water glass increased with the ration increased.②When the special surface of slag is form 302m2/kg to 517m2/kg, the coulombs decreased with the special surface increased in the same conditions, the chloride ion permeability increased with special surface increased.③In the same conditions, The reinforcement corrosion of Alkali activated slag concrete activated water glass decreased with alkali content and the modulus of water glass increased.④When the fly ash content is from 30% to 70%, the coulombs passed concrete increased with the content increased. The Chloride ion permeability increased with the content increased, and the reinforcement corrosion of Alkali activated slag concrete decreased. From the point of view of controlling chloride ion permeability and reinforcement corrosion in alkali activated slag concrete, the amount of fly ash taking the place of slag should be lower than 50%.When the silica fume content is from 5% to 15%, the coulombs passed concrete decreased with the content increased. The Chloride ion permeability decreased with the content decreased, and the reinforcement corrosion of Alkali activated slag concrete increased.⑤The coulombs passed concrete activated by glass water is lower than ordinary Portland cement concrete, and the reinforcement corrosion is better than ordinary Portland cement concrete. But the reinforcement corrosion of concrete activated by NaOH is lower than ordinary Portland cement concrete.⑥The coulombs passed Alkali activated slag concrete and the mass loss ratio of reinforcement is related, but it is not a simple linear relationship.⑦Appropriately increasing special surface of slag, modulus of water glass and alkali content module to improve the pore structure of Alkali activated slag cement concrete and enhance the density of interfacial transition zone.