EN 15435:2008

SLOVENSKI STANDARD
01-september-2008
Montažni betonski izdelki - Normalni in lahki betonski bloki - Značilnosti in
obnašanje izdelkov
Precast concrete products - Normal weight and lightweight concrete shuttering blocks -
Product properties and performance
Betonfertigteile - Schalungssteine aus Normal- und Leichtbeton - Produkteigenschaften
und Leistungsmerkmale
Produits préfabriqués en béton - Blocs de coffrage en béton de granulats courants et
légers - Exigences et méthode d'essai
Ta slovenski standard je istoveten z: EN 15435:2008
ICS:
91.100.30 Beton in betonski izdelki Concrete and concrete
products
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 15435
NORME EUROPÉENNE
EUROPÄISCHE NORM
April 2008
ICS 91.100.30
English Version
Precast concrete products - Normal weight and lightweight
concrete shuttering blocks - Product properties and performance
Produits préfabriqués en béton - Blocs de coffrage en Betonfertigteile - Schalungssteine aus Normal- und
béton de granulats courants et légers - Propriétés et Leichtbeton - Produkteigenschaften und
performances des produits Leistungsmerkmale
This European Standard was approved by CEN on 18 March 2008.
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 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 Management Centre has the same status as the
official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2008 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 15435:2008: E
worldwide for CEN national Members.

Contents Page
Foreword.4
1 Scope.5
2 Normative references.5
3 Terms, definitions and symbols.6
3.1 Terms and definitions .6
3.2 Symbols.7
4 Requirements.8
4.1 General.8
4.2 Raw materials and concrete .9
4.3 Dangerous substances.9
4.4 Geometric properties.9
4.5 Density.10
4.6 Moisture movement.10
4.7 Reaction to fire.10
4.8 Water vapour permeability.10
4.9 Mechanical strength.10
4.10 Acoustic properties.11
4.11 Thermal properties.11
4.12 Water absorption by capillarity .11
4.13 Durability.11
5 Test methods.12
5.1 Geometric properties.12
5.2 Density.14
5.3 Mechanical strength.15
6 Classification.15
7 Marking.16
8 Evaluation of conformity.16
8.1 General.16
8.2 Initial type testing .16
8.3 Factory production control.17
Annex A (normative) Determination of web tensile strength .18
A.1 Principle.18
A.2 Apparatus.18
A.3 Procedure.19
A.4 Determining the tensile strength of webs .21
A.5 Test report.23
Annex B (normative) Determination of shell flexural strength.24
B.1 Principle.24
B.2 Apparatus.24
B.3 Procedure.24
B.4 Determining the flexural strength of the shells .24
B.5 Test report.28
Annex C (normative) Sampling for initial type testing .29
C.1 General.29
C.2 Sampling procedure.29
C.3 Place and dates of inspection and acceptance testing .31
Annex D (normative) Compliance criteria for initial type testing and for independent batch
acceptance testing .32
Annex E (informative) Example of inspection schemes .33
E.1 Equipment inspection.33
E.2 Materials inspection.34
E.3 Production process inspection.35
E.4 Product inspection.36
E.5 Switching rules.37
Annex F (informative) Filling pressure of concrete infill .38
Annex ZA (informative) Clauses of this European Standard addressing the provisions of the EU
Construction Products Directive .39
ZA.1 Scope and relevant characteristics.39
ZA.2 Procedure for attestation of conformity of concrete shuttering blocks.40
ZA.3 CE marking and labelling .42
Bibliography.44

Foreword
This document (EN 15435:2008) has been prepared by Technical Committee CEN/TC 229 “Precast concret
products”, 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 October 2008, and conflicting national standards shall be withdrawn at
the latest by January 2010.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
This document has been prepared under a mandate given to CEN by the European Commission and the
European Free Trade Association, and supports essential requirements of EU Construction Products Directive
(89/106/EC).
For relationship with EU Directive(s), see informative Annex ZA, which is an integral part of this document.
It also takes into account the “Common rules for precast concrete products” in EN 13369.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.

1 Scope
This European Standard specifies the properties, performance and test methods of factory made, non-load
bearing hollow concrete shuttering blocks made from normal weight or lightweight aggregates or a
combination of both. Shuttering blocks may include vertical or horizontal interlocking features and factory
installed supplementary insulation. Shuttering blocks are intended to be used to form walls and partitions
when filled with concrete or mortar. Concrete shuttering blocks rely on a concrete or mortar infill for their
structural performance and are not intended to be used unfilled.
This standard does not cover masonry units covered in EN 771-3.
2 Normative references
The following referenced documents are indispensable for the application 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 772-11, Methods of test for masonry units — Part 11: Determination of water absorption of aggregate
concrete, manufactured stone and natural stone masonry units due to capillary action and the initial rate of
water absorption of clay masonry units
EN 772-14, Methods of test for masonry units - Part 14: Determination of moisture movement of aggregate
concrete and manufactured stone masonry units
EN 772-16, Methods of test for masonry units — Part 16: Determination of dimensions
EN 772-20, Methods of test for masonry units - Part 20: Determination of flatness of faces of aggregate
concrete, manufactured stone and natural stone masonry units
EN 1745, Masonry and masonry products — Methods for determining design thermal values
EN 12390-5:2000, Testing hardened concrete — Part 5: Flexural strength of test specimens
EN 12664, Thermal performance of building materials and products - Determination of thermal resistance by
means of guarded hot plate and heat flow meter methods - Dry and moist products of medium and low
thermal resistance
EN 13369, Common rules for precast concrete products
EN 13501-1, Fire classification of construction products and building elements - Part 1: Classification using
data from reaction to fire tests
EN ISO 12572, Hygrothermal performance of building materials and products — Determination of water
vapour transmission properties (ISO 12572:2001)
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
shuttering block
hollow block, sometimes incorporating lateral interlocking, intended as permanent formwork for concrete or
mortar infill, for laying dry or with mortar

Figure 1 — Example of a shuttering block
3.1.2
shuttering block with supplementary thermal insulation
shuttering block incorporating thermal insulation to enhance thermal resistance

Figure 2 — Examples of shuttering blocks with supplementary thermal insulation
3.1.3
design (nominal) dimension
dimension targeted in the project documentation
3.1.4
actual dimension (of the product)
dimension found by measurement (on the finished product)
3.1.5
specially shaped shuttering block
shuttering block having a shape, such as a corner block, which allows it to fulfil a particular function
3.1.6
interlocking features (horizontal and/or vertical)
shaped matched projections and indentations on shuttering blocks (e.g. tongue and groove systems)
3.1.7
hollow core
shaped void for incorporation of concrete or mortar infill and any supplementary thermal insulation
3.1.8
shell
solid material between the hollow core and the faces of a shuttering block
3.1.9
web
solid material linking the shells of the shuttering block
3.1.10
web recess
formed notch in a web
3.2 Symbols
l length of the shuttering block in mm
t width of the shuttering block in mm
b
h
height of the shuttering block in mm
t thickness of the outer shell in mm
s1
t thickness of the inner shell in mm
s2
t (w , w , etc.) thickness of web in mm
1 2
w1
t width of the hollow core (concrete infill) in mm
c
W width of web recess
R
t thickness of the insulating material in mm
i
h Total height of the web in mm (h = h + h )
R R1 R2
R
A
Total area of the web recess in mm
R
l diagonal of the face
d
h recessed height of web (h = h – h – h )

w W R1 R2
a length of hollow core
a length of cantilevered shell
Figure 3 — Geometric specification symbols
4 Requirements
4.1 General
The requirements and properties specified in this European Standard shall be defined in terms of the test
methods and other procedures referred in this European Standard.
NOTE The standard test methods are not always applicable to specially shaped shuttering blocks as defined in 3.1.5.
4.2 Raw materials and concrete
Materials for shuttering block concrete shall comply with EN 13369. Any supplementary thermal insulation
material shall comply with an appropriate European standard.
4.3 Dangerous substances
Shuttering blocks shall not release any dangerous substances in excess of the maximum permitted levels
specified or permitted in the national regulations valid in the place of use.
4.4 Geometric properties
4.4.1 Dimensions
The dimensions of the shuttering blocks shall be declared in millimetres for length, width and height, in that
order (see Figure 3). The dimensions of voids and web recesses shall be declared in millimetres. They shall
be given in terms of work size and be shown on diagrams. Tolerances on declared work sizes of individual
regular shaped shuttering blocks shall conform to Table 1. Closer deviations may be declared by the
manufacturer for one or more dimensions.
The thickness of shell(s) and web(s) shall be declared.
Table 1 — Permissible deviations in millimetres
Dimensions
of voids and
Length Width Height
web
recesses
(l) (t) (h)
b
+5 +5 +3 +10
-5 -5 -5 -4
4.4.2 Web recess area
When web recesses are included the minimum web recess area shall be declared. The web recess area shall
be determined in accordance with 5.1.4.
4.4.3 Flatness
4.4.3.1 Flatness of external faces of facing shuttering blocks
When the surface of facing shuttering blocks is declared as plane, it shall not deviate from a plane by more
than 0,1 √l mm or 2 mm whichever is the greater, where l is the length of the diagonal of the face. The
d d
flatness of external faces of facing shuttering blocks shall be determined in accordance with 5.1.5.
4.4.3.2 Flatness of bed faces
When the shuttering blocks are dry-stacked the flatness of bed faces shall be determined in accordance with
5.1.6.The deviation from flatness shall not exceed 3 mm.
4.4.4 Squareness
When required, squareness between the side-faces and both bed faces for shuttering blocks to be dry-
stacked shall not deviate by more than 5 mm when measured in accordance with 5.1.3.2. or 3 mm when
measured in accordance with 5.1.3.3.
4.4.5 Appearance of facing shuttering blocks
When required, the appearance of facing shuttering blocks may have compliance established on the basis of
comparison with any approved samples. Comparison shall be made from a distance of 3 m in normal daylight
conditions. This compliance shall be established before the shuttering blocks are used.
4.5 Density
The net dry density of the shuttering blocks shall be declared in kg/m . The mean value of the test samples
shall not differ from the declared value by more than ± 10 %. The dry density shall be determined according to
5.2.
For factory production control purposes, density may be verified by weighing individual shuttering blocks.
4.6 Moisture movement
When required, the moisture movement of the shuttering blocks (shrinkage and expansion) shall be declared.
Moisture movement shall be determined according to EN 772-14.
4.7 Reaction to fire
For concrete shuttering blocks intended to be used in elements subject to fire requirements, the manufacturer
shall declare the reaction to fire classification of the shuttering block.
Shuttering blocks containing a mass or volume fraction of a maximum of 1,0 % (whichever is the most
onerous) of homogeneously distributed organic materials, are classified as Class A1 without the need to test.
Shuttering blocks containing a mass or volume fraction more than 1,0 % (whichever is the most onerous) of
homogeneously distributed organic materials shall be classified in accordance with EN 13501-1 and the
appropriate reaction to fire class declared.
Information on reaction to fire class of supplementary insulating material shall be given on the basis of
European standards as declared by the supplier of the insulating material.
NOTE Attention is drawn to the Commission Decision 96/603/EC, as amended by Commission
Decision 2000/605/EC, in which non-combustible shuttering blocks containing not more than a mass or volume fraction of
1,0 % (whichever is the more onerous) of homogeneously distributed organic materials are classified as reaction to fire
Class A1 without testing.
4.8 Water vapour permeability
When required, the water vapour permeability shall be declared according to tabulated values in EN 1745 or
determined according to EN ISO 12572.
4.9 Mechanical strength
4.9.1 General
The mechanical strength of shuttering blocks shall be sufficient to allow handling and withstand the filling
pressure on the shells.
For factory production control purposes mechanical strength may be verified by testing compressive strength
in accordance with EN 772-1.
When relevant, the thermal insulation adhesion shall be determined according to 5.3 and declared.
NOTE Determination of thermal insulation adhesion can be relevant for blocks where thermal insulation binds
together two block halves, see last block type in Figure 2.
4.9.2 Tensile strength of webs
The mean tensile strength shall be determined only when the web width is less than the shell width and/or the
web height is less than 80 % of the shuttering block height.
The tensile strength in N/mm² of the webs f shall be determined on the smallest section of the webs
t,fl
according to 5.3 and shall not be less than the design value f .
t,min
Shuttering blocks shall be tested according to 5.3 and Annex A, the results evaluated according to Annex D.
4.9.3 Flexural strength of shells
The mean flexural strength in N/mm² of the shell f , shall not be less than f .
f
f,m ,min
The flexural strength of the shells shall be determined on the thinnest shell according to 5.3.
Shuttering blocks shall be tested according to 5.3 and Annex B, results evaluated according to Annex D.
4.10 Acoustic properties
When required, the manufacturer shall supply information on the acoustic properties.
NOTE 1 The acoustic properties depend mainly on the density and configuration of the shuttering blocks and/or on the
mass of the finished walls.
NOTE 2 Airborne sound insulation is a property of the finished walls.
4.11 Thermal properties
When required, the manufacturer shall supply information on the thermal properties.
The thermal conductivity shall be declared on the basis of tabulated values given in EN 1745 or determined in
accordance with EN 12664.
NOTE The thermal properties depend mainly on the thermal conductivity of the shuttering blocks, the concrete or

mortar infill, any supplementary insulation and the geometry of the shuttering blocks.
4.12 Water absorption by capillarity
When required, the maximum water absorption by capillarity shall be declared in g/m².s.
The test is carried out in accordance with EN 772-11 for a time in contact with water of (10,0 ± 0,2) min.
NOTE The result obtained according to EN 772-11 should be divided by 24,49 to express this value in g/m .s.
4.13 Durability
When required freeze-thaw resistance shall be declared by reference to the provisions valid in the intended
place of use until an appropriate European standard is available.
5 Test methods
5.1 Geometric properties
5.1.1 General
The geometric properties are measured on complete shuttering blocks.
The results are evaluated according to Annex D.
5.1.2 Dimensions
The length, width and height of shuttering blocks shall be measured according to method c) of EN 772-16.
The length and width of each hollow core shall be measured at the centre of the hollow core at the top and
bottom of the shuttering block. Mean values of the length and width are calculated from each pair of
measurements, rounded to the nearest millimetre, then compared with the declared dimensions.
5.1.3 Squareness
5.1.3.1 General
The squareness shall be measured on a low wall or directly on shuttering blocks.
5.1.3.2 Measurement on low wall
A low dry-stacked test-wall shall be built as specified.
The first course shall contain at least four shuttering blocks and shall be at least two metres long.
The height h of the low wall shall be at least one metre.
e
NOTE
Effective height of the low wall (he)
hi
∑
he =
hi = h1, h2, h3, h4
Effective verticality of the low wall (Ve)
The batter or opposite batter is measured at ends of the wall on both sides.

Figure 4 — Principle of measurement of squareness of a low wall
 Squareness (pe)
pe = hi – hi
max min (1)
Key
1 Batter (Ve)
2 Perpendicularity level = 0 mm
3 Base
4 Thickness of the low wall
5 Opposite batter (Ve)
Figure 5 — Definition of batter and opposite batter
5.1.3.3 Measurement on shuttering blocks
The deviation from squareness of the side-faces and both bed faces shall be measured using a steel angle
and feeler gauges and given in millimetres.

Figure 6 — Measurement of squareness directly on shuttering blocks
5.1.4 Web recess area
The area of each web recess shall be determined to the nearest 10 mm , by measurement and calculation.
5.1.5 Flatness of external faces of a facing shuttering block
The deviation from flatness of the face shall be measured in accordance with Figure 7. The result shall be
expressed in millimetres.
5.1.6 Flatness of bed faces
The deviation from flatness of bed faces shall be measured in accordance with Figure 7. The result shall be
expressed in millimetres.
Key
1 Deviation
Figure 7 — Measurement of flatness of bed face
5.2 Density
The oven dry density shall be established from three cut test specimens having individual volumes of at
least 3 000 cm , which have been dried to constant mass at 105 °C ± 5 °C.
A specimen may be comprised of more than one cut piece of shuttering block if each piece has a minimum
volume of 750 cm .
Constant mass (m ) is considered to have been reached when the results of two successive weighings carried
u
out at 24 h intervals differ by not more than 0,5 % of the mass of the specimen.
The volume (V ) of each specimen or constituent piece of a specimen is measured to the nearest millimetre
u
and each specimen is weighed to the nearest gram. The gross dry density of each specimen is calculated to
3 3 3
the nearest 5 kg/m for densities up to 1 000 kg/m and, above this, to the nearest 10 kg/m . The dry density of
each specimen is calculated according to:
m
u,n 6
ρ = ×10 (2)
u,n
V
u,n
Density is established as the mean value of the density of the three test specimens and evaluated in
accordance with Annex D.
5.3 Mechanical strength
For reference testing of mechanical strength shuttering blocks shall be stored in the laboratory at a
temperature of > 15 °C and a relative humidity of < 65 % for 28 days.
For factory production control mechanical strength tests can be carried out at less than 28 days (e.g. prior to
delivery).
Thermal insulation adhesion is determined by tension test according to Figure 8.

Key
1 Softening pad e.g. rubber
Figure 8 — Thermal insulation adhesion test
6 Classification
Specification of the properties of the shuttering blocks may be given by reference to national classification
systems on the condition that those systems are based only on single properties included in this European
standard and do not themselves constitute a barrier to trade.
This condition does not remove the requirement that all manufacturers claiming compliance with this
European standard shall state declared values of the properties of their products, when required.
NOTE Details of classification systems in current use may be given in informative national annexes.
7 Marking
The following information shall be marked clearly on the packaging, the delivery note, the certificate
accompanying the shuttering blocks or on 5 % of the shuttering blocks, with at least four per pack of shuttering
blocks:
a) name, trademark or other means of identifying the manufacturer;
b) means of identifying the date of manufacture of the shuttering blocks;
c) means of identifying the shuttering blocks and relating them to their description and designation.
NOTE For CE marking and labelling, Article ZA.3 applies. Where Article ZA.3 requires the CE marking to be
accompanied by the same information as required by this article, the requirements of the latter can be considered to have
been met.
8 Evaluation of conformity
8.1 General
The manufacturer shall demonstrate the compliance of the product with the requirements of this European
Standard and with the values stated for the product specifications by carrying out both:
 initial type testing of the product (see 8.2) ;
 factory production control (see 8.3).
Test methods other than the reference methods specified in this European Standard may be adopted, except
for initial type tests and in the event of a dispute, provided that these alternative methods satisfy the following
conditions:
a) correlation can be demonstrated between the results from the reference test and those from the
alternative test and
b) information on which such correlation is based is available.
8.2 Initial type testing
When a new product type is developed, and before offering it for sale, appropriate initial type tests shall be
carried out to confirm that the achieved properties of the product meet the requirements of this European
Standard and the values stated by the manufacturer. Type testing consists of a complete set of tests or other
procedures described in this European standard. Whenever a major change occurs in the raw materials, the
proportions used or the production process, which would change the properties of the finished product, the
appropriate initial type test shall be repeated.
Previous type tests on the same products may be considered if they comply with the requirements of this
standard.
The type tests shall correspond to the reference tests mentioned in Table C.1 for the properties selected for
the manufacturer’s declaration according to the intended use of this product type.
Sampling for initial type testing shall be carried out in accordance with Annex C.
The number of shuttering blocks to be tested shall be as given in Table C.1 and the criteria specified in
Clause 4 shall be met.
The results of the initial type tests shall be recorded.
NOTE To determine the performance characteristics allowing for compliance with the CE marking provisions, see
Table ZA.1.
8.3 Factory production control
8.3.1 General
A factory production control system shall be set up and documented. This system shall be made up of internal
production control procedures in order to ensure that the products put on the market comply with this
European Standard and the values stated by the manufacturer.
The factory production control system shall consist of procedures, regular inspection and tests and the
utilisation of the results to control raw and other incoming materials, equipment, the production process and
the product.
An example of a suitable inspection scheme for factory production control is given in Annex E.
The results of inspections requiring action and the results of tests shall be recorded.
The action to be taken when control values or criteria are not met shall be given.
8.3.2 Raw materials
The specifications of the raw materials used and the procedures to be implemented to ensure that they
comply shall be documented.
8.3.3 Production process
The relevant features applicable to the plant and the production process shall be defined, giving the frequency
of the inspections, checks and tests, together with the criteria required both on equipment and on work
progress. The action to be taken when inspection parameters or criteria are not complied with shall be stated.
All test equipment shall be verified and the procedure, frequency and criteria documented.
8.3.4 Finished product testing
A sampling plan and the conformity criteria shall be set out for the testing of finished products, the results of
which shall be recorded and available. All test equipment shall be verified and the procedure, frequency and
criteria documented.
8.3.5 Stock control
Stock control of finished products, together with the procedures for dealing with non-compliant products shall
be documented.
Annex A
(normative)
Determination of web tensile strength
A.1 Principle
The method determines the tensile strength directly or uses a standard compression (or flexural) testing
machine in conjunction with a special device which converts the compressive force (normal) into a tensile
force.
A.2 Apparatus
Tensile testing machine or compression testing machine.
When the compression testing machine is used, a special device comprising two interlocking U shapes with
holes for two pairs of 20 mm diameter rods is needed.
Two rods are used to support the specimen and two rods are used to transmit the tensile force to the
specimen. The lower part of the device is static.
The upper part of the device can be moved with the movements of the platen of the compression testing
machine.
Key
1 Hinge
2 Upper section of the frame
3 Rods
4 Specimen (web)
5 Lower section of the frame
6 Platen of the testing machine
Figure A.1 — Test equipment for web tensile strength test
A.3 Procedure
Six webs are cut from six shuttering blocks (see Figure A.6).
The shoulders on either side of the webs shall extend at least 40 mm from the web.
When tensile testing machine is used, the tensile force is submitted to the test specimen according to the
principle shown in Figure A.6.
When compression testing machine is used the two parts of the steel device (see Figure A.2) are assembled
and the two retaining rods are inserted through the frame and under the shoulders of a test specimen.
The two pull rods are then inserted through the frame using holes in close proximity to the lower shoulders of
the test specimen (see Figure A.3) and the specimen is centred on the retaining rods (see Figure A.4). It is
possible to introduce a flexible packer between block and rod for the adjustment of the location of the rods.

Key
1 Retaining rod 1
2 Retaining rod 2
Figure A.2 — Insertion of two retaining rods to support the specimen

Key
1 Retaining rod 1
2 Retaining rod 2
3 Pull rod 1
4 Pull rod 2
Figure A.3 — Insertion of two retaining rods to support the specimen
The moving platen of the compression testing machine is then activated until the pull rods are in light contact
with the lower shoulders of the test specimen. Packaging pieces may be used, if the shoulder geometry on
either side of the web is different

Key
1 Retaining rod 1
2 Retaining rod 2
3 Pull rod 1
4 Pull rod 2
Figure A.4 — Centring of specimen on the retaining rods

Key
1 Retaining rod 1
2 Retaining rod 2
3 Pull rod 1
4 Pull rod 2
Figure A.5 — Web undergoing tensile strength test
The load is applied at a rate of (0,10 ± 0,05) N/mm per second. A constant loading rate shall be maintained
for at least the second half of the loading. During the first half of the assumed maximum load a higher rate of
loading is permitted (see Figure A.5).
A.4 Determining the tensile strength of webs
A.4.1 General
Key
a Length of hollow core in mm
a Length of cantilevered part of the shell in mm
t Thickness of web in mm
w1
t Width (thickness) of unit in mm
b
h Height of unit in mm
h Height of recessed web in mm
w
p Filling pressure in N/mm²
P Web tensile load in N
t
Figure A.6 — Tensile strength of web
A.4.2 Calculation of the design tensile strength of the web
For each specimen the design web tensile strength (f ) in N/mm² shall be calculated on the basis of the
t,min
maximum filling pressure of concrete infill (p ) according to Annex F using the formula:
max
P
t,min
f = (A.1)
t,min
s
where
Webs situated between two hollow cores:
a a
 
1 1
P =()ρ × h × +  (A.1a)
t,min max
2 2
 
Webs situated between hollow core and cantilevered end of shell:
 a 
P =()ρ × h × + a (A.1b)
 
t,min max 2
 
where
f is the design web tensile strength in N/mm²;
t,min
P is the minimum required web tensile failure load in N;
t,min
s is the cross-sectional area of recessed web = (t h ) in mm²;
1 w1 x w
ρ is the maximum filling pressure of concrete infill in N/mm²;
max
a , a is the length of hollow space in mm;
1 2
h is the height of block in mm.
A.4.3 Measurement of the web tensile failure load and calculation of the tensile strength of
webs
The web tensile failure load (P ) in N of six specimens shall be determined.
t,msd
From the measured web tensile failure load (P ) in N calculate the individual values of web tensile strength
t,msd
(f ) in N/mm² and, subsequently, the mean tensile strength of webs (f ) in N/mm²:
t,msd t,m
P
t,msd
f =
(A.3)
t,msd
s
f
t,msd,i
∑
i=1
f = (A.4)
t,m
where
f is the individual value of the web tensile strength in N/mm²;
t,msd
P is the measured web tensile failure load in N;
t,msd
s is the cross-sectional area of recessed web = (t h ) in mm²;
1 x
w1 w
f is the mean tensile strength of webs in N/mm²;
t,m
f is the individual values of the web tensile strength in N/mm².
t,msd,i
A.5 Test report
The test report shall contain the following information:
1) laboratory that carried out the tests;
2) date of the tests;
3) description of the shuttering blocks tested;
4) age of the shuttering blocks at the time of the test;
5) individual values of measured tensile force applied to the webs P in N;

t, msd
6) designed web tensile strength f
t,min in N/mm ;
7) mean tensile strength of webs f
t,m in N/mm .
Annex B
(normative)
Determination of shell flexural strength
B.1 Principle
The method uses a standard flexural strength testing machine.
B.2 Apparatus
The test device consists of a loading roller centred relative to the two lower rollers, all having a diameter of
(20 ± 2) mm. The device shall permit the free rotation of the loading roller and of one of the lower rollers as
shown in Figure 2 of EN 12390-5:2000.
B.3 Procedure
Six specimens are prepared by cutting sections from shells taken from six shuttering blocks of the same type
and with the same dimensions (see Figure B.1).
The required specimen length is that of one core plus the thickness of two webs.
Place the specimen on the testing machine, the support rollers are adjusted so that the distance between
them equals the length of the void in the shuttering blocks plus the width of the adjoining web. The specimen
is located squarely on the lower rollers with each roller centrally under a web. The upper roller is then located
centrally between the two support rollers.
Select a constant loading rate of (0,1 ± 0,05) N/mm per second. A constant loading rate should be
maintained for at least the second half of loading. For the first part of the assumed maximum load a higher
rate of loading is permitted.
B.4 Determining the flexural strength of the shells
B.4.1 General
Record the flexural failure load of the shells (P ) in N of the six specimens.
f, msd
h height of shuttering block in mm

a length of hollow space in mm

t thickness of web in mm
w1
t thickness of shells in mm
s
ρ filling pressure in N/mm
ρ maximum filling pressure in N/mm

max
P minimum shell flexural failure load in N

f,min
P measured shell flexural load in N

f,msd
f minimum flexural strength of shells in N/mm

f,min
f individual values of flexural strength of shells in N/mm

f,msd
f mean flexural strength of shells in N/mm

f,m
Where
P is the shell flexural load
f
l is the distance between the axis of 2 webs
Figure B.1 — Testing of shell flexural strength
B.4.2 Calculation of the design flexural strength of shells
For each specimen the design shell flexural strength (f ) shall be calculated on the basis of the maximum
f,min
filling pressure of concrete infill (ρ ).
max
NOTE For calculation of the design shell flexural strength the structural system of a fixed end beam and - as far as
given – a cantilever, stressed by a uniformly distributed load, is used.

Key
1 Fixed end beam
2 Cantilever
a Length of hollow space in mm
a Length of cantilevered shell in mm
ρ Filling pressure of concrete infill in N/mm²
f Design shell flexural strength in N/mm²
f,min
Figure B.2 — Static system of calculation design shell flexural strength

...