The fire resistance period (FRP) for structural adequacy is specific to the wall type and its boundary support conditions.
AS 3700 permits charts derived from test results to be used for any fired clay bricks that are of the same type as those in the tested walls. These charts allow designers to assess the fire resistance level (FRL) for a specific wall type and enables the FRP for structural adequacy to be directly read from the charts. More details on fire resistance levels are available in Brick Manual 1.
Note: In the terms of AS3700 the same type means clay and shales of the same mineralogy and geological type, blended in the same proportions and manufactured by similar processes.
The following charts are derived in accordance with AS 3700 from tests on loadbearing walls. They can be applied to all walls, whether loadbearing or non-loadbearing. The following test reports have been used as the basis for these charts:
The thickness of the units and the edge support conditions are indicated with icons adjacent to each chart. Hatching along a wall edge indicates a support to that edge. The lines for FRL 90 minutes represent the limit of the range of available test results. They should therefore be used for any fire resistance level lower than 90 minutes.
For walls supported only at the top and bottom, the limiting heights are shown in the table below. For walls with support on one or both vertical edges, the limiting heights approach these values as the length increases. This behaviour can be seen in the charts for cases where the top of the wall is supported.
Note: Designers should also check for robustness and resistance to applied loads in all cases.