An Experimental Study on the Mechanical Properties and Seavater-resistance of Concrete as using Cement Types

This study carried out the tests of seawater-resistance of concrete by diversifying cement types in order to provide the basic data for selection of cement type and concrete mix design in marine concrete structures. From the test results, the concrete used Type V cement(high sulfate resistance portland cement) was far better than the concrete used Type I cement (ordinary portland cement) in the resistance of sulfate ion, but the former was worse than the latter in the resistance of chloride attack, and this trend came out more clearly in 1% of C3A than 4% of C3A in cement. Therefore C3A was verified as an important factor which has an effect on the chloride ion permeation of concrete. Also, the cement which replaced the part of Type I cement with fly ash was as good as the concrete which used Type V cement both in long-term ages and in the resistance of sulfate ion. The former was better than the latter in age process, compressive strength, drying shrinkage, void ratio, and the resistance of chloride permeation.