Investigation on Relationship Between Long Term and Short Term Tests of Chloride Diffusion Coefficient

Abstract

AbstractGenerally, in order to determine the chloride diffusion coefficient of concrete, many test methods have been developed; those are divided into two terms: long term tests and short term tests. The long-term test has an advantage that it characterizes the natural penetration in the real environment, however it has also a disadvantage that it takes long time (90 days), while the advantage of short-term test is that it accelerates test so it takes short time (24 h up to 4 days), but its disadvantage is of not the natural penetration in the actual environment. In this paper, the short term and long term of the chloride diffusion coefficients of the same concretes were evaluated, then the relationship between short-term and long-term test of chloride diffusion coefficient was established. The concrete specimens were casted with water to binder ratio (w/b) as 0.3, 0.4, 0.5 and 0.6. The binder contained Ordinary Portland cement, fly ash, silicafume and granulated blast furnace slag. Results showed that experimental data of short-term test can be converted to those of pounding test that is more reliable. Also, there was a fact that chloride diffusion coefficient from short-term tests, accelerating tests, are always higher than these from long-term test. And, there was a linear relationship between short-term test and long-term test.KeywordsChloride diffusion coefficientLong term testMineral admixtures