SIST EN 1794-2:2025

SLOVENSKI STANDARD
01-januar-2025
Nadomešča:
SIST EN 1794-2:2020
Protihrupne ovire za cestni promet - Neakustične lastnosti - 2. del: Metode
ugotavljanja splošnih značilnosti glede varnosti in okolja
Road traffic noise reducing devices - Non-acoustic performance - Part 2: Methods of
determination of the general safety and environmental characteristics
Lärmschutzvorrichtungen an Straßen - Nichtakustische Eigenschaften - Teil 2: Methoden
zur Bestimmung der allgemeinen Sicherheits- und Umwelteigenschaften
Dispositifs de réduction du bruit du trafic routier - Performances non acoustiques - Partie
2 : Méthodes de détermination des caractéristiques générales de sécurité et des
caractéristiques environnementales
Ta slovenski standard je istoveten z: EN 1794-2:2024
ICS:
13.020.99 Drugi standardi v zvezi z Other standards related to
varstvom okolja environmental protection
17.140.30 Emisija hrupa transportnih Noise emitted by means of
sredstev transport
93.080.30 Cestna oprema in pomožne Road equipment and
naprave installations
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 1794-2
EUROPEAN STANDARD
NORME EUROPÉENNE
October 2024
EUROPÄISCHE NORM
ICS 93.080.30 Supersedes EN 1794-2:2020
English Version
Road traffic noise reducing devices - Non-acoustic
performance - Part 2: Methods of determination of the
general safety and environmental characteristics
Dispositifs de réduction du bruit du trafic routier - Lärmschutzvorrichtungen an Straßen - Nichtakustische
Performances non acoustiques - Partie 2 : Méthodes de Eigenschaften - Teil 2: Methoden zur Bestimmung der
détermination des caractéristiques générales de allgemeinen Sicherheits- und Umweltmerkmale
sécurité et des caractéristiques environnementales
This European Standard was approved by CEN on 12 August 2024.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2024 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 1794-2:2024 E
worldwide for CEN national Members.

Contents Page
European foreword . 4
Introduction . 5
1 Scope . 6
2 Normative references . 6
3 Terms, definitions and symbols . 6
3.1 Terms and definitions . 6
3.2 Symbols . 7
4 Characteristics . 8
4.1 Safety in case of brushwood fire . 8
4.2 Resistance to dynamic loads: risk of falling debris . 8
4.3 Environmental protection . 8
4.4 Access for maintenance and emergency exits . 8
4.5 Light reflection . 8
4.6 Transparency . 8
5 Test report . 8
Annex A (normative) Safety in case of brushwood fire .10
A.1 General .10
A.2 Characteristics .10
A.3 Fire test .10
A.4 Test report .11
Annex B (normative) Resistance to dynamic loads: risk of falling debris .12
B.1 General .12
B.2 Characteristics .12
B.3 Test method .13
Annex C (normative) Environmental protection .16
C.1 General .16
C.2 Characteristics .16
Annex D (normative) Access for maintenance and emergency exits .17
D.1 General .17
D.2 Characteristics .17
Annex E (normative) Light reflection.19
E.1 General .19
E.2 Characteristics .19
E.3 Test method .19
E.4 Test report . 21
Annex F (informative) Transparency . 22
F.1 General . 22
F.2 Definition of transparency . 22
F.3 Static transparency . 23
F.4 Dynamic transparency . 24
F.5 Methodology . 24
F.6 Uncertainty in calculation of effective transparency . 28
Bibliography . 30
European foreword
This document (EN 1794-2:2024) has been prepared by Technical Committee CEN/TC 226 “Road
equipment”, the secretariat of which is held by AFNOR.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by April 2025, and conflicting national standards shall be
withdrawn at the latest by April 2025.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 1794-2:2020.
— The annexes were renumbered. Annex A now includes the safety in case of brushwood fire.
This document is part of the EN 1794 series, which consists of the following parts under the general title
“Road traffic noise reducing devices — Non-acoustic performance”:
— Part 1: Methods of determination of the mechanical and stability characteristics;
— Part 2: Methods of determination of the general safety and environmental characteristics.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia,
Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland,
Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North
Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the United
Kingdom.
Introduction
While performing their primary function, road traffic noise reducing devices should not pose hazards to
road users or other people in the vicinity or to the environment at large. Noise reducing devices should
not reflect light in such a way as to prejudice road safety. They should be made from materials which do
not emit noxious fumes or leachates as the result of natural or industrial processes, or as the result of fire.
Noise reducing devices should allow a means of escape by road users and access by operatives in the
event of an emergency or for maintenance.
1 Scope
This document specifies methods and criteria for assessing the general safety and environmental
performance of road traffic noise reducing devices under typical roadside conditions. Appropriate test
methods are provided where these are necessary. The treatment of each topic is covered separately in
Annexes A to F.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
EN 1794-1:2024, Road traffic noise reducing devices — Non-acoustic performance — Part 1: Mechanical
performance and stability characteristics
EN ISO 2813:2014, Paints and varnishes - Determination of gloss value at 20°, 60° and 85° (ISO 2813:2014)
3 Terms, definitions and symbols
3.1 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1.1
road traffic noise reducing device
RTNRD
device designed to reduce the propagation of traffic noise away from the road environment
Note 1 to entry: RTNRDs can comprise acoustic elements (3.1.2) only, or both structural (3.1.3) and acoustic
elements.
Note 2 to entry: Applications of RTNRDs include noise barriers (3.1.5), claddings (3.1.6), covers (3.1.7) and added
devices (3.1.8).
3.1.2
acoustic element
element whose primary function is to provide the acoustic performance of the device
3.1.3
structural element
element whose primary function is to support or hold in place the parts of the RTNRD
3.1.4
self-supporting acoustic element
acoustic element including its own structural element to support itself
3.1.5
noise barrier
noise-reducing device which obstructs the direct transmission of airborne sound emanating from road
traffic
3.1.6
cladding
noise-reducing device which is attached to a wall or other structure and reduces the amount of sound
reflected
3.1.7
cover
noise-reducing device which either spans or overhangs the road
3.1.8
added device
additional component that influences the acoustic performance of the original noise-reducing device
Note 1 to entry: The added device is acting primarily on the diffracted energy.
3.2 Symbols
For the purposes of this document, the following symbols apply:
ϕ angle at which reflections from the surface of the transparent material obscure
m
the view through the material, in degrees
ϕ angle between the visual axis and the normal to the noise reducing device (see
Figure F.2) in degrees
ϴ angle of incidence
αn angle of transparency (see Figure F.2) in degrees
α angle (see Figure B.1)
ß angle of opacity (see Figure F.2) in degrees
n
η angle of the transparent Elements
µ terms of refractive index
t function of the angle of incidence
θ
K visual acuity factor (see Figure F.1) in degrees
A
k Parameter
L light transmission index (as determined in accordance with EN 410 or
T
EN 2155-5), in percent
’
LT overall transparency for different material thickness t’
L /100 coefficient
T
r radius (see Figure B.1)
S area of opaque features within transparent elements, in square millimetres
O
S total area of transparent elements, including horizontal features, in square
T
millimetres
t/t’ material thickness/ different material thickness
T transparency, in percent
T transparency looking right, in percent
r
T transparency looking left, in percent
l
T dynamic transparency, in percent
D
T static transparency, in percent
S
u estimated uncertainties
i
u sum of the estimated combined uncertainties
T
u the square of the uncertainty in T
T
w weights
i
4 Characteristics
4.1 Safety in case of brushwood fire
The safety in case of brushfire shall be determined in accordance with Annex A.
4.2 Resistance to dynamic loads: risk of falling debris
When secondary safety has to be determined, this shall be done in accordance with Annex B.
4.3 Environmental protection
The constituent materials and their breakdown products shall be identified in accordance with Annex C.
4.4 Access for maintenance and emergency exits
The acoustic and mechanical performances of doors or other means of escape shall be determined in
accordance with Annex D.
4.5 Light reflection
The results of a standard test of reflectivity shall be determined in accordance with Annex E.
4.6 Transparency
The results of a standard test of transparency should be determined in accordance with Annex F.
5 Test report
Every test report shall include the following information:
a) number and year of this document, i.e. EN 1794-2:2024;
b) full description of the element or system tested, including manufacturer(s), part numbers, place and
date of origin;
c) description of the method of sampling, description of the sampling procedure, if the performance is
determined by parts of manufactured elements;
d) place and date of determination, and the name of the responsible person(s);
e) sufficient description of any tests carried out, any results measured, and the conclusions drawn about
the product together with any illustrations or photographs, all as specified in the appropriate annex;
f) A summary of information shall be produced, identifying the aspects and the level of performance
assessed, where appropriate.
Annex A
(normative)
Safety in case of brushwood fire
A.1 General
A road traffic noise reducing device can be exposed to fire arising from dry vegetation or other material
in close proximity. More severe fires from spilt fuel can arise as the result of traffic accidents.
Where a road traffic noise reducing device is in close 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 materials or other
design are incorporated into the road traffic noise reducing device in order to prevent the propagation of
fire. 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 Characteristics
The noise reducing device, after being tested by the method given in A.3, shall be classified as follows:
— class 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.2.1 Acoustic elements of at least 2 m long by 1,5 m high shall be tested by exposure to localized
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.2.2 Testing shall be carried out in an enclosed fireproof and draught-free chamber having a volume
of at least 150 m .
Fume extraction devices can 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.2.3 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, equally spaced 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 % 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.2.4 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 plinth 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.2.5 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.3.1 The test shall be documented together with time stamps of significant observations 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.3.2 Photographs of the test panel before, during and after the test shall be supplied and shall include
an appropriate means of judging scale.
Annex B
(normative)
Resistance to dynamic loads: risk of falling debris
B.1 General
Road traffic noise reducing devices can be mounted on structures or in such a way that if damaged they
could pose a hazard to road users or to others. In particular, even if the road traffic noise reducing device
is protected by the safety system on an elevated structure, there is a possibility of pieces or whole panels
from a noise barrier becoming detached as the result of a violent collision and for the debris to fall,
endangering those below.
Road traffic noise reducing devices which are to be used in a vulnerable position can be required to be
restrained by internal or external linkage between panels and/or elements to prevent them from
becoming detached and falling.
The standard provides some general indications of factors which need to be considered and also provides
a method of establishing the resistance of a product to a severe blow.
NOTE It is principally the responsibility of specifiers to consider the potential consequences of noise barriers
becoming damaged and to provide protection accordingly.
Alternatively, a
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