Preparation Technology And Application Of Anticorrosive Concrete Box Culvert

The corrosion resistance and durability of reinforced concrete structure is a common concern issue in engineering and academic fields.The structural concrete has been widely used in major projects.With the rapid development of old to new kinetic energy conversion and economic construction in in Shandong Province,there is a huge amount of structural concrete construction in the coastal area.The key development areas are mostly beach areas with corrosive medium,the construction of infrastructure is imminent.The reinforced concrete structure is an important part of infrastructure,the research and development of prefabricated reinforced concrete box culvert that can effectively prevent the corrosion of sulfate and chloride is of great significance.In this study,the properties,classification,function and application range of concrete preservatives were systematically analyzed in accordance with the standard specification,the preparation technology and application method of preservatives for concrete box culvert were established.Based on the environmental effect grade and related parameters,a series of anticorrosive concrete are developed by using multi-component composite technology,and the preparation technology of anticorrosive concrete was proposed systematically.The influence of mineral admixture and preservative amount on the workability,mechanical properties and durability of concrete,combined with economic analysis,the benchmark mix proportion of anticorrosive pre-stressed concrete was optimized;the mix proportion design principle of anticorrosive pre-stressed concrete box culvert was determined,the optimum production mix proportion of anticorrosive box culvert was established,and the production technology,product inspection standard,construction technology and application fields of anticorrosive concrete box culvert were put forward.The specific research results were as follows :(1)Based on strength data analysis,linear regression and economic analysis,and the replacement ratio of mineral admixture was 30% and 40%,the preservative content was 10%,and water reducing admixture content was 1.2% for the total content of cementitious materials.According to the design strength of concrete,the optimum mix proportion of anticorrosive concrete was proposed.(2)According to the grading and durability requirements of environmental effect,the anti-Cl-permeability of anticorrosive concrete was good,and the Cl-diffusion coefficient was less than 4.3×10-12 m2/s;the compressive strength and corrosion resistance coefficient of anticorrosive concrete with large mineral admixtures were all over 97.7% after 150 sulfate dry-wet cycles;the relative dynamic elastic modulus and quality of anticorrosive concrete were better than 78% after 200 cycles of freezing and thawing.The relative dynamic modulus of elasticity and mass loss met the design requirements,and the frost resistance was good.(3)The anti-corrosive concrete box culvert of C45 was developed by multi-component composite technology.The mechanical properties of concrete met the design requirements.The sulfate resistance grade reached KS150,and the appearance quality was stable,the surface finish was high,and the surface of clear-water concrete box culvert with better quality could be realized.