Compounding Of High Durability Concrete And Application In Strong Corrosive Environment

The total salinized soils and potential secondary salinized soils in China are about 520,000 square kilometers,accounting for about 5.4% of China's total land area and widely distributed in northwestern Xinjiang,Qinghai,Tibet,Gansu,Ningxia and InnerMongolia Lowlands of northern and northeastern plains,lower edges of lakes or piedmont alluvial fans,and eastern coastal zones.As saline-alkali soil is rich in chloride ion and sulfate ion,which have strong corrosive to concrete,how to improve the durability of concrete in saline-alkali soil,which is a strong corrosive environment,is needed to solve the problem by engineering construction technicians.In this paper,there are five kinds of anticorrosive measures commonly used in engineering construction are grouped and tested,including increasing the design strength of concrete(decreasing the water-to-binder ratio),adding mineral admixture,adding sulfate corrosion-resistance admixtures for concrete(or sulfate corrosionresistance and corrosion-inhibiting admixtures for concrete),sulfate resistance Portland cement instead of ordinary Portland cement,anti-corrosion coating applied anticorrosion measures were tested concrete compressive strength,electrical flux,resistance to chloride ion permeability,anti-sulfate wet and dry cycle levels and other projects.The research on effect and mechanism of different anticorrosive measures to improve the resistance of sulfate concrete to sulfate attack and chloride ion corrosion,and the anticorrosion measures suitable for different corrosion environments were put forward.According to the applicable conditions of different anti-corrosion measures and the corrosive environmental conditions of the project site,combined with the current design criteria of durability of concrete,the appropriate anti-corrosion measures for the actual construction projects are raised and the application of the project is verified.The results show that improving the design strength of concrete(reducing the water-to-binder ratio)can improve the durability of concrete.However,based on the experience of previous projects,increasing the design strength of concrete will directly increase the construction cost and increase the difficulty of construction.In practical engineering are more limitations.Adding mineral admixture can improve the density of concrete,meanwhile reduce the content of C3 A in concrete cementations materials and improve the anti-sulfate chemical corrosion of concrete.Adding sulfate corrosionresistance admixtures for concrete(or sulfate corrosion-resistance and corrosioninhibiting admixtures for concrete),can increase the density of concrete,reduce chloride ion permeability,and can improve the anti-sulfate physical corrosion.The use of sulfate resistance Portland cement instead of ordinary Portland cement,improve the anti-sulfate chemical corrosion of concrete.And the use of sulfate resistance Portland cement and sulfate corrosion-resistance admixtures for concrete can improve both anti-sulfate chemical corrosion and physical corrosion of concrete.The anticorrosive coating is mainly used to isolate the surface of concrete from the outside water and reduce the infiltration of corrosive ions into the concrete to improve the resistance against chloride ion permeability and sulfate corrosion of the concrete and use it as an auxiliary measure in the key areas.