Chloride And Sulphate In The Mortar And Concrete In The Deposition Characteristics Of The Study

Corrosive salt medium in the environment is the main reason causing concrete durability. Based on the interaction analysis between the salt medium and the cement based materials, the deposited ions at the different location in the mortar and concrete under different conditions were tested, and the effect of the water to binder ratio, mineral admixture, solution concentration and immersion conditions on the deposited chloride ions and sulfate ions in the mortar and concrete was studied. The rule of the ions deposition velocity in the mortar and concrete was analyzed. The research can provide scientific advice for controlling the durability problem caused by the corroive salt medium. The paper obtains the following results:1)Reducing the water to binder ratio and adding mineral admixture can decrease the deposit numbers of the chloride ion and sulfate ion.2)The condition of mixing sulfate ion with chloride ion can decrease the deposit numbers of the chloride ion and sulfate ion.3)The deposit rule of the chloride ion is different from the sulfate ion, the increase rate of the deposit chloride ion is fast firstly and is slow late, and increase rate of the deposit sulfate ion has three stages.4) The ion deposition velocity parameter was put forward, and the ion deposition equation was established.5)Mineral admixture can delay the deposit rate of ion in the cement based materials significantly.6)There are difference between the inner chloride deposit rate and the surface rate, and the time index in the inner location is larger than that in the surface.7) Based on the ion diffusion and deposit process, the time that the chloride ion concentration in the surface of the steel bar in the concrete protection layer reach the limited value was calculated.