Study On Preparation And Properties Of High Resistance To Chloride Penetration For Sea Sand Concrete

Coastal engineering concrete always use of high chloride ion content of sea sands,and the concrete service for a long time at a high temperature and high salt,high humidity of environment,leads to concrete chloride ion erosion resistance is poor and the steel is easy to rust.Therefore developed a high resistance chloride penetration sea sand concrete to enhance the resistance to chloride ion erosion of coastal engineering properties and durability is of great significance.This paper chooses the most commonly used mineral powder and fly ash as mineral admixture,preparing the low air-entraining low-release slump retaining superplasticizer and multifunctional agent to improve working performance,mechanical property and durability of the concrete.This study first explore mineral admixture of sea sand concrete working performance and the influence of the compressive strength.Found mixing mineral powder and fly ash double in sea sand concrete,the working performance and compressive strength of the sea sand concrete has a significant effect.The mineral powder to improve the working performance of the sea sand concrete is better than fly ash,but mixed with fly ash can reduce the early strength of concrete.When mixed 20% of mineral powder and 30% of fly ash in sea sand concrete,sea sand concrete performance the best compressive strength.This research explores the factors affect the performance of low air-entraining low-release slump retaining superplasticizer dispersion properties and air-entraining,found that when the polymer concentration of 50%,dosage of chain transfer agent was 0.7%,the oxidation reduction ratio of 1:2,made by the low air-entraining slow-release slump retaining superplasticizer dispersing performance,maintain the optimum performance and bleed air performance.The performance indexes of low air-entraining low-release slump retaining superplasticizer meet the requirements of national standard of water reducing agent.Compared with the superplasticizer on the market product,homemade superplasticizer with low dosage,high collapse,the advantages of low air-entraining.This study prepared multifunctional agent containing chloride ion curing part and cementitious materials optimizationt part.Through the multifunctional optimal cementitious materials performance test found that multifunctional agent is to improve the fresh concrete secrete water phenomenon,reinforced concrete 7 d,28 d compressive strength,reduce the content of free chlorine ion in concrete.In this paper,the study found that chloride ion concentrations in different environment,different ways of chloride ions into the sea sand concrete chloride ion curing ability is different.Introduced by mixing water chlorine ion,chlorine ion in concrete evenly dispersed,chloride ion curing than bigger.Sea sand concrete curing chloride than there is a limit.Environment in the chloride ion concentration on the sea sand concrete chloride ion distribution have a significant impact.When high concentrations of chloride ion environment,concrete chloride ion concentration difference is big,inside and outside gradient,the more obvious,the diffusion of chloride ions in concrete of the more obvious,the rate of diffusion.Electric flux environment on the sea sand concrete chloride ion concentration have a significant impact.Environment of chlorine ion concentration is higher,the corresponding power is higher,that is to say,the more the resistance to chloride ion permeability of concrete is poor,the greater the permeability of concrete.This study of the preparation of high chloride ion erosion of concrete and ordinary concrete microstructure morphology has obvious differences.Ordinary concrete large pore,structure is relatively loose,and in high concrete chloride ion erosion pore is refined,large aperture less holes,appeared mostly in small aperture porosity,structure is more compact.This study has prepared a high resistance chloride penetration sea sand concrete performanced high resistance chloride penetration,achieved the desired goal.To strengthen the durability of concrete construction in coastal regions has a certain significance.