Methods Of Testing Alkali-Silica Reactivity In The Netherlands
Original hosted in "MACE", contributed by Social Updater
In the current Dutch standard NEN 5905 and CUR Recommendation 38, four methods are listed for assessing the alkali-silica reactivity of concrete aggregates. However, procedures outlining how the tests should be performed, and the possible errors associated with such tests, are not given. This makes interpretation of results obtained by any of these methods quite difficult and often impossible. In 2000, the Dutch Ministry of Transport, Public Works and Water Management published a draft procedure for assessing the potential alkali-silica reactivity of concrete aggregates in a fast but robust manner. This procedure, which is intended to form one of the backbone's of the currently reviewed CUR Recommendation 38, consists of a combination of petrographic examination and expansion measurements. For expansion measurement, mortar bars are prepared with the test aggregate, following an assessment in an ultra-accelerated mortar-bar test based on the RILEM TC 106-2 method. This article summarizes the essential elements of the new test procedure, and presents results of tests of several primary as well as secondary (recycled) aggregates.