The Iceland Building Research Institute has requested that a frost resistance test for aggregates using salt-water as the freezing media should be included in the test standards of CEN TC 154 'Aggregates'. A multinational research group was established to carry out research on frost resistance of aggregates. The research project is called FRAS (Frost Resistance test on Aggregates with and without Salt). The primary aim of the project was to conduct a precision trial to test aggregates in pure water according to EN 1367-1 and salt water according to NT BUILD 485. Aggregates from different sources in Europe were tested at laboratories in different countries. Aggregates that were considered poor tended to show different results when tested in pure water and salt water. Limestone and basalt disintegrated in salt water but only slightly in pure water, whereas granite was not affected by testing in salt water. The results confirmed the hypothesis that the salt water test method identified frost susceptible aggregates without affecting frost resistant aggregates too much.
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