Studied On The Carbonation Resistance And Chloride Ion Resistance Of Concrete Under The Early Water Curing

Concrete durability is the key to ensure the structure service life， thereinforcement corrosion in concrete structure caused by concrete carbonation and theCl-erosion is the chief problem of concrete durability. Material properties and theinternal defect is the most basic part of the concrete durability research, also is theintrinsic factor of insufficient durability. Early curing conditions have a vital influenceon the initial defects and holes in concrete internal structure and have importantinfluence on concrete durability. Adopting reasonable maintenance system andexcellent proportion is the most effective and economic way to ensure the concretestrength, durability and control the early crack. This paper obtained the best earlywater curing way for each concrete and which concrete with optimal performancethrough the early high temperature water experiment and the later carbonationexperiment, electric flux experiment, salt fog experiment about concrete specimenmixed with fly ash, mineral powder and silica fume.Through the early water curing experiments for four kinds concrete, we canobtain the concrete strength development order from fast to slow under the normaltemperature: before the40%design strength is ordinary concrete, concrete mixedsingle ores,concrete mixed double ores, concrete mixed three ores;after that isconcrete mixed three ores, concrete mixed double ores, concrete mixed single ores,ordinary concrete. And we can obtain the early high temperature water curing systemfor each concrete according to the maturity theory, which system can shorten themaintenance time effectively and ensure the concrete compressive strength.Through the carbonation experiment after the early high temperature watercuring, we can obtain the concrete carbonation resistance order by superior to inferioris ordinary concrete, concrete mixed double ores, concrete mixed three ores, concretemixed single ores. The long-term carbonation resistance is good after the hightemperature water curing, and the ordinary concrete carbonation resistance is best in40℃water curing. The carbonation resistance of concrete mixed ores is good with≥20%precuring strength and≤60℃water curing temperature, and the carbonationresistance is best in60℃water curing.Through the electric flux experiment after the early high temperature watercuring, we can obtain the concrete chloride ion resistance order by superior to inferioris concrete mixed three ores, concrete mixed double ores, concrete mixed single ores, ordinary concrete. The long-term chloride ion resistance is good after the hightemperature water curing, and the ordinary concrete chloride ion resistance is best in20℃water curing. The chloride ion resistance of concrete mixed ores is good with≥20%precuring strength, and the chloride ion resistance is best in60℃watercuring.Through the salt fog experiment after the early high temperature water curing,we can obtain the salt fog resistance of concrete is same with the chloride ionresistance, so we can replace the salt fog experiment for the electric flux experimentto inspect concrete chloride ion resistance.According to the above three kinds of durability test research conclusion, we canobtain that the concrete with≥20%precuring strength can ensure concrete durabilityafter the early high temperature water curing. The best early water curing temperaturefor ordinary concrete is20℃to40℃, the best early water curing temperature forconcrete mixed ores is60℃,and the concrete mixed double ores is the durableperformance optimum mixture ratio.