Scale effect in the evaluation of the fire resistance of glazed partitions

Abstract

Fire-resistance testing procedures for glazed partitions used in Europe determine the minimum dimensions of the test items (2.8 × 3.0 m, width × height in the furnace opening lumen). Tests on minimum-sized items enable the evaluation of the fire resistance of slightly larger components. Nonetheless, they do not address the real problem of using fire-resistant glazed partitions, whose heights significantly exceed the dimensions of partitions verified in tests. This study resulted in the development of a model based on testing minimum-sized items, enabling the fire resistance evaluation of aluminium glazed partitions that are much higher than the test items. A typical scale effect should be expected in this situation, resulting from the difference in the dimensions of the test sample and the actual glass partition. The model was developed based on the results of eight tests on glazed partitions. The tests performed showed that there is a relationship between the profile stiffness in a glazed partition's mullion and the mullion's deflection during a fire-resistance test. Moreover, it was observed that if a low partition maintains its fire integrity and insulation, identical behaviour can be expected of higher partitions in specific conditions. These phenomena aimed to develop an algorithm that enables the evaluation of the maximum acceptable height of an aluminium glazed partition for which the fire resistance is maintained.