Study On New Type Of Anti High Concentration Sulfate Corrosion Agent And Its Concrete Performance

In recent years,sulfate corrosion has become an important factor that greatly influence the service life of bridge engineering structures at home and abroad,especially for the concrete structures existing.In the environment that suffer from sulfate erosion and changeful temperature and humidity.Currently,there are some problems of research,the lack of the resistance to sulfate erosion such as single influence factors,plain micro research,the lack of study of diffusion law and immature matching technology,which lead to the existing,research results and standard specification does not satisfy the need of concrete design under sulfate environment,evaluation index is difficult ti meet the needs of practical performance.In the existing technology platform of modern concrete,it is necessary to improve the ability of concrete to resist high concentration sulfate attack under the action of multiple factors.In order to improve the resistance to high concentration sulfate erosion of concrete in the practical engineering,this paper studies a new type of anti high concentration sulfate erosion agent and analysis its influence on mortar and concrete performance by comparing with the foreign anti sulfate erosion agent.The results show that mortar and concrete adding high concentration sulfate erosion agent with the mix of barium salt and sodium benzoate has the least water absorption,the max strength and the most stable strength development trend.Inorganic salt resistance to sulfate erosion agent has good water blocking effect,which can reduce the water absorption,improve flexural strength and compressive strength of mortar(W/B=0.5),and delay the infiltration of external sulfate ion.The macroscopic properties and micro structure of C30 concrete mixed with different anti high concentration sulfate erosion agent can retard corrosive solution in to the internal structure and reduce water absorption rate,occur chemical reaction to increase density of concrete,improve compressive strength of concrete,reduce the risk of sulfate attack,and improve its durability.After 150 times corrosion of sulfate wet and dry cycles,AFt and CaSO4 were found in concrete without anti sulfate erosion agent,and it suffer from sulfate erosion damage to the greatest extent and the most fast,concrete with Ketai generated thaumasite crystaland and CaSO4,which has smaller destruction degree;concrete with anti sulfate erosion agent generated CaSO4 internally,which suffered from sulfate erosion damage to the least extent and the most slowly.The results show that the new anti high sulfate corrosion agent can improve the resistance to sulfate corrosion of C30 concrete,reduce the surface water absorption rate and had no significant effect on other properties of concrete.According to the research on sulfate corrosion of concrete,we believe that the current standard test method for resistance of concrete sulfate attack exist problems,even if C30 concrete(W/B=0.5)can also meet the requirements of KS150,there are no unqualified test results more than 30 groups of concrete,we question that the current methods for concrete sulfate corrosion resistance evaluation is not sensitive.