EN 1794-2-2011 pdf download.Road traffic noise reducing devices – Non-acoustic performance- Part 2: General safety and environmental requirements.
Where a noise reducing device is in dose proximity to property it can also be necessary to consider the need to ensure that fire is not spread from the highway.
Where flammable systems are used, it is recommended that firebreaks of fire-resistant matenals or other design are incorporated into the noise reducing device in order to prevent the propagation of lire. This annex is not applicable to such fire resistant material.
This annex describes a test for a representative panel of a vertical noise barrier under normal exposure to brushwood fires at the roadside.
It does not provide information on the results of exposure to more severe conditions e.g. ignition by burning spilt fuel. The test should not be used to provide information on the fire safety of claddings used for tunnels or partial covers over the highway.
A.2 Requirements
The noise reducing device, after being tested by the method given in A.3, shall be dassified as follows:
— dass 1: if the panel has been damaged to a greater extent than as defined for classes 2 and 3;
class 2: if the damaged area above either source is less than 0.06 m2 and extends to no more than 200 mm above the base of the panel, and the panel has not been burnt through to the other side
— class 3: if there is no damage other than discoloration.
A.3 Fire test
A.3.1 Acoustic elements of at least 2 m long by 1,5 m high shall be tested by exposure to localised sources of fire at its base next to the front and rear faces independently. Panels shall be free of absorbed water before testing: in the case of timber components, the moisture content shall be reduced to 18 % by an approved drying method.
The mass and dimensions of the panel to be tested shall be measured and the panel shall be photographed. An identical panel shall be examined to determine its construction; the dimensions of its elements, including wall thickness of hollow sections. shall be measured and noted on a sketch at 1:20 scale.
A.3.2 Testing shall be carried out in an enclosed fireproof and draught-free chamber having a volume of at least 150 m3.
Fume extraction devices may be installed in or near the ceiling, but shall be prevented from fanning any flames during the test.
The temperature of the chamber, including the floor, before the test begins shall be between 15 C and 25 °C. The chamber should be fitted with an observation port or window in a suitable position to observe the panel during the test.
A.3.3 Two identical sources of fire shall be prepared as follows:
a) a rectilinear wire mesh basket 300 mm by 200 mm by 300 mm high shall be made from welded steel wire mesh, having a square mesh of 3 mm diameter drawn steel wire at 50 mm centres;
b) in addition, three 3 mm diameter wires 300 mm long shall be secured in a vertical position inside the basket, equispaced along the central line of the shorter dimension.
The flammable material shall comprise shavings of spruce, 0,2 mm thick by 2 mm wide, and approximately 50 mm long. The material shall be free from splinters and have a maximum moisture content of 30 %: It shall be acclimatised at 20 C and 65 % relative humidity until its weight is constant.
600 g of shavings shall be lightly pressed down into each basket so that it is just filled.
A.3.4 The test panel shall be supported in a vertical position corresponding to its orientation in use, on a plinth supporting the full length of the panel. The plinth shall be of masonry or concrete and have a vertical step to a level of 250 mm above the floor of the chamber. The base of the test panel shall be completely in contact with the pllnth and the face to be tested shall be flush with the edge. The two sources of fire shall be placed on the floor of the chamber with their longer dimension flush against the plinth and the face of the test panel. Both sources shall be lit simultaneously, and the time taken for the test shall start at this point.
A.3.5 The performance of the panel shall be observed during the test and the time at which any significant change takes place recorded. After the sources of fire and any part of the panel which may have ignited have burnt out, the panel shall be examined and the extent of any damage photographed and measured. The opposite face of the panel shall not be tested until it and the floor of the chamber have cooled to below 25 °C.
A.4 Test report
A.4.1 The test procedure shall be described together with the timing of significant stages, indication of, for example maximum intensity of flames, the incidence of any observed changes to the test panel and the number of samples tested.
The test report shall record the nature and extent of any flames and smoke produced during the test.
A.4.2 Photographs of the test panel before, during and after the test shall be supplied and shall include an appropriate means of judging scale.EN 1794-2-2011 pdf download.

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