Abstract
A new test system to quantitatively evaluate alkali-silica reactivity of aggregate is proposed. In this test system, at first, change of soluble silica content of aggregate with the passage of time is measured by a leaching test at various temperatures. The results obtained from this test are analyzed on the basis of kinetics in order to obtain alkali diffusion coefficient in aggregate and alkali-silica ratio of reaction products, and also to evaluate the effect of temperature on diffusion coefficient, which are main factors in predicting the progress of ASR. Expansion behaviors and ultimate expansion ratios of mortar bars can be calculated by using these values. And expansion curves of mortar bars observed experimentally almost coincide with the calculated expansion curves. It was also found that the alkali diffusion coefficients in sedimentary rocks change during ASR.
