Study On Corrosion Resistance Of Concrete Under Domestic Sewage Environment In Tianjin

Concrete as a composite material,with a wide range of applicability,low cost and other advantages have been widely used in city drainaga and sewage treatment systems engineering.Urban drainage pipeline is an important and indispensable facility in modern urban construction.It is also an important symbol of modernization of a city,and has a very important impact on the city's economic development.Improve the durability of concrete has become an urgent problem in today's civil engineering industry to solve.In the urban sewage environment,the sewage treatment structure and transport structure concrete to be a variety of strong acid,alkali,organic matter,inorganic and microbial corrosion,but also by the complex mechanical impact and abrasion and climate factors together.With the rapid development of China's economic construction and urbanization process,urban sewage(including industrial wastewater and domestic sewage)has become a more prominent problem in current environmental management.At present,most of our cities use concrete underground underground pipe,but the traditional concrete pipe corrosion resistance is poor,long service in the sewage environment has a different degree of corrosion damage.The deterioration of concrete under the environment of sewage is the result of the superposition of various factors,and the mechanism of concrete corrosion is not the same in the wet and dry cycle near the water level interface and the underwater area.In this paper,the corrosion mechanism of concrete structure is studied according to the actual situation of Tianjin domestic sewage,and the application of new materials to improve the corrosion resistance of concrete.Under the condition of anaerobic and dry-wet cycle,the attenuation law of concrete structure is studied,and the durability of different modified concrete under different environment is predicted.It provides important basis for the design of concrete under the environment and prolonging the service life of concrete.The results show that it is shown that the corrosion of concrete is obviously aggravated by the dry and humid environment,and the incorporation of basalt fiber can improve the corrosion resistance of concrete obviously.When the basalt content is 0.10%,the effect is the most obvious.The incorporation of fly ash can significantly improve the corrosion resistance of concrete,fly ash content continues to improve,and can not continue to enhance its corrosion resistance,the fly ash content of about 20% to improve the effect of the most obvious.Concrete gas content in a certain range can significantly improve the corrosion resistance of concrete.However,the increase in concrete content will significantly reduce the compressive strength.Gas content increased to a certain value,not only the intensity decreased significantly,corrosion resistance and did not continue to be improved.Considering the corrosion resistance of concrete with different gas content in different environments,the optimum gas content is 3% ~4%.