AS 1530.8.1:2018 pdf free.Methods for fire tests on building materials, components and structures Part 8.1: Tests on elements of construction for buildings exposed to simulated bushfire attack—Radiant heat and small flaming sources.
3.2 Test exposure conditions
3.2.1 Burning embers
Exposure to burning embers impinging on the vertical and underside of exposed horizontal surfaces is simulated by application of a small gas flame to volatiles released from combustible materials.
3.2.2 Burning debris
Exposure to burning debris and the collection of burning embers on the upper surface of horizontal and near-horizontal surfaces is simulated by pre-ignited timber cribs.
Four sizes of timber crib are available. The selection of size of the crib and position for application are based on the potential for debris to collect. The crib size (Class A) is representative of debris that may collect around a building with reasonable levels of housekeeping/block maintenance and is the default size unless otherwise specified by AS 3959. Class B and C cribs simulate collections of debris that are representative of larger collections of debris, which may be more appropriate for facilities and structures that are not regularly maintained or where it is expected that accumulation of debris may occur, for example, a heat shield of sacrificial structure and remote infrastructure services.
The method does not apply to large volumes of combustible materials stored adjacent to the building or exposure to flames from adjacent structures. This test will identify excessive flammable elements of construction and elements susceptible to thermal shock from small flaming sources in addition to evaluating whether small fires may weaken the performance of an element of construction. If the impact of exposure to radiant heat is also being evaluated, the crib will have to be applied and exposure to the radiant heat profile commenced simultaneously.
3.2.3 Radiant heat
Element(s) of construction are exposed to a radiant heat profile under controlled conditions simulating the passage of the fire front adjacent to the structure.
During the test, a pilot ignition source is applied to exposed combustibles and volatiles on the exposed face (simulating ember attack and burning cribs) and is applied to simulate burning debris as described in Clause 3.2.1. Conditions are monitored for a period of 60 mm from commencement of radiant heat exposure to evaluate the risk of ignition or re-ignition and incipient spread of fire within an element of construction.
NOTES:
1 It is recognized that radiant heat profiles will vary from one bushfire to the next as will the extent and nature of attack from burning embers and debris. The radiant heat exposure conditions specified in this Standard have been selected to represent a rapidly approaching bushfire to maximize the potential for thermal shock, a constant peak radiant heat flux maintained for a period of 2 mm and a slow reduction in radiant heat to maximize the total applied heat load. The specified profiles are expected to be conservative for most bushfire exposures except some glazed elements, which may be susceptible to thermal shock during the cooling phase.
2 The radiant heat test is adapted from the test procedure for wall systems exposed to radiant heat given in AS 1530.4, with modifications to the heating profiles to simulate the transient peak from the fire front, application of flaming sources to simulated burning debris, modified conditioning requirements and modified criteria applicable to bushfires.AS 1530.8.1 pdf download.