Corrosion Mechanism And Protection Of Microorganism On Concrete Durability

As a civil engineering material,concrete is used most widely and largely.Due to the characteristics of the concrete structure itself and the environment,making the lack of concrete structure durability and other issues have appeared,which have caused significant economic losses.The problems of resources,energy and environmental protection are becoming more and more prominent.The durability of concrete structure is generally concerned in the field of engineering nowadays,it not only relates to the cost control of the maintenance and reconstruction of concrete structure,but also closely related to energy saving and emission reduction,environmental protection and sustainable development of society.As one of components of municipal engineering,concrete sewer is an important instrument which ensure the normal production and life.However,the research shows that some concrete pipelines have been destroyed before the design life because of the microbial corrosion.In view of the seriousness and inevitability of microbial corrosion of concrete structures,it is imperative to study the environmental conditions of microbial growth and the mechanism of erosion of concrete.This paper focused on the impact of microorganisms on the durability of concrete.and the degradation mechanism of concrete durability was analyzed,mainly for the corrosion of underground concrete pipe.This thesis studied the following aspects:(1)This paper summarized the main factors that affects the durability of concrete,and analyzed the mechanism of carbonation,chloride ion attack,alkali aggregate reaction,freeze-thaw cycle destruction and sulfate attack.(2)The erosion mechanism of the microorganism under the corrosive environment was studied,and found that the corrosion of the concrete in the anaerobic environment was the most serious.(3)In this paper,the life prediction model of concrete resistance to sulfate erosion was established,and the concrete life in corrosive environment was predicted and verifid by engineering examples.(4)Based on the study of corrosion mechanism,this paper introduced the measures to improve the durability of reinforced concrete in sewage pipes.The polyurethane technology was introduced to improve the corrosion resistance of concrete.Based on the analysis of the durability deterioration mechanism of the concrete structures,the erosion mechanism of microorganisms was studied.The life prediction equation of concrete resistance to sulfate attack under microbial environment was established,which provided technical support for the durability assessment of existing sewer pipes and the durability design of new structures.