Fire resistance performance of concretes exposed to high temperatures

Concrete cubes of 150mm size were cast and the compaction of the fresh concrete of all the mixtures was made on a vibrating table. Then the moulds were covered with a wet cloth for 48 hours. Then the specimens were taken from the moulds and kept in a chamber with 90% relative humidity at temperature 27°C ± 2°C prior to testing. All the specimens were then taken from the chamber not earlier than 1 hour before testing.