Experimental study on chloride ion transport in concrete under the coupling effect of multi-factor
Chloride ions,sulfate ions and magnesium ions in seawater are the main corrosive ions in marine reinforced concrete structures.Sulfate ion and magnesium ion erosion cause changes in properties and permeability of physical mechanics of concrete,and chloride ion corrosion is the main factor of steel bar corrosion.The effect of sulfate ion and magnesium ion corrosion on chloride ion transport under the marine tidal cycle is a subject to be studied.To this end,three corrosive solutions,namely single chloride ion,chloride ion+sulfate ion and chloride ion+sulfate ion+magnesium ion,were designed to simulate water level changes using the tidal cycle system to carry out natural exposure tests on concrete.Relative dynamic module of elasticity,chloride ion concentration distribution,porosity and pore diameter distribution of concrete are measured at different exposure times,and the microscopic morphology of corrosion products are also analyzed to probe into the effects of sulfate ions,magnesium ions and wet-dry ratio on chloride ion transport.The results indicate that the existence of sulfate ions and magnesium ions increase the relative dynamic module of elasticity of concrete,decrease the chloride ion concentration,and reduce the porosity and the most available pore diameter during the 200 d exposure time.Compared with sulfate ions,the inhibition of chloride ion transport is more transparent when magnesium ions and sulfate ions are coupled.
concretemulti-ion corrosiondry-wet cyclesmaterial propertychloride ion transport
万方数据
维普
