Accelerated test methods for evaluating alkali-silica reactivity of recycled concrete aggregates
thesisposted on 08.06.2021, 11:03 by Robert C Johnson
This thesis reports the findings of a study carried out to determine the effectiveness of Accelerated Tests in evaluating the Alkali-Silica Reactivity of Recycled Concrete Aggregates. The study evaluated the variability of the Accelerated Mortar Bar Test due to test variables as well as the single and multi-laboratory variation. The variability of the Concrete Microbar Test due to test variables and the correlation to results from Accelerated Mortar Bar and Concrete Prism Test results were also evaluated. The tests were corroborated by comparing the porosity, permeability and alkali binding capacity of samples tested by the accelerated tests. It was found that the Accelerated Mortar Bar Test provides acceptable results when the test variables, such as crushing methods and absorption values, are carried out and evaluated properly. The Concrete Microbar Test was found to underestimate the expansion of reactive aggregates. However, the same test was found to provide good correlation to the expansion results of Concrete Prisms incorporating Supplementary Cementing Materials when the test duration was increased.