prEN 13381-6

SLOVENSKI STANDARD
01-december-2008
3UHVNXVQHPHWRGH]DXJRWDYOMDQMHSULVSHYNDNSRåDUQLRGSRUQRVWLNRQVWUXNFLMVNLK
HOHPHQWRYGHO=DãþLWDYRWOLKMHNOHQLKVWHEURYVSROQLORPL]EHWRQD
Test methods for determining the contribution to the fire resistance of structural members
- Part 6: Applied protection to concrete filled hollow steel columns
Prüfverfahren zur Bestimmung des Beitrages zum Feuerwiderstand von tragenden
Bauteilen - Teil 6: Brandschutzmaßnahmen für betonverfüllte Stahlverbund-Hohlstützen
Méthodes d'essai pour déterminer la contribution à la résistance au feu des éléments de
construction - Partie 6: Protection appliquée aux poteaux métalliques creux remplis de
béton
Ta slovenski standard je istoveten z: prEN 13381-6
ICS:
13.220.50 Požarna odpornost Fire-resistance of building
gradbenih materialov in materials and elements
elementov
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
DRAFT
NORME EUROPÉENNE
EUROPÄISCHE NORM
October 2008
ICS Will supersede ENV 13381-6:2002
English Version
Test methods for determining the contribution to the fire
resistance of structural members - Part 6: Applied protection to
concrete filled hollow steel columns
Méthodes d'essai pour déterminer la contribution à la Prüfverfahren zur Bestimmung des Beitrages zum
résistance au feu des éléments de construction - Partie 6: Feuerwiderstand von tragenden Bauteilen - Teil 6:
Protection appliquée aux poteaux métalliques creux remplis Brandschutzmaßnahmen für betonverfüllte Stahlverbund-
de béton Hohlstützen
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee CEN/TC 127.
If this draft becomes a European Standard, 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.
This draft European Standard was established by CEN 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.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are aware and to
provide supporting documentation.
Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without notice and
shall not be referred to as a European Standard.
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. prEN 13381-6:2008: E
worldwide for CEN national Members.

Contents Page
Foreword. 4
1 Scope. 5
2 Normative references. 5
3 Terms and definitions, symbols and units. 6
3.1 Terms and definitions. 6
3.2 Symbols and units . 7
4 Test equipment. 7
4.1 General. 7
4.2 Furnace. 7
4.3 Loading equipment. 8
5 Test conditions. 8
5.1 General. 8
5.2 Support and restraint conditions for columns . 8
5.3 Loading conditions. 8
6 Test specimens. 9
6.1 Number of test specimens . 9
6.2 Size of test specimens. 9
6.3 Construction of test specimens . 9
6.3.1 Construction of concrete filled hollow steel test columns. 9
6.3.2 Application of the fire protection system to the composite test column. 10
6.4 Composition of components of test specimen. 10
6.4.1 Hollow steel column . 10
6.4.2 Concrete. 10
6.4.3 Fire protection system. 10
6.5 Properties of test materials. 11
6.5.1 General. 11
6.5.2 Concrete. 11
6.5.3 Steel. 11
6.5.4 Fire protection material . 11
6.6 Verification of the test specimen. 12
7 Installation of the test construction. 12
7.1 Loaded test column . 12
7.2 Unloaded specimen. 12
8 Conditioning of the test construction. 12
9 Application of instrumentation. 13
9.1 General. 13
9.2 Instrumentation for the measurement of furnace temperature. 13
9.3 Instrumentation for measurement of test specimen temperature . 13
9.3.1 General. 13
9.3.2 Mandatory thermocouples. 13
9.3.3 Optional thermocouples. 13
9.4 Instrumentation for measurement of pressure. 13
9.5 Instrumentation for measurement of deformation . 14
9.6 Instrumentation for measurement of applied load . 14
10 Test procedure. 14
10.1 General. 14
10.2 Furnace temperature and pressure. 14
10.3 Application and control of load . 14
10.4 Temperature of test specimen. 14
10.5 Deformation. 14
10.6 Observations. 14
10.7 Termination of test. 15
11 Test results. 15
11.1 Acceptability of test results . 15
11.2 Presentation of test results. 15
12 Test report. 16
13 Assessment. 16
13.1 General. 16
13.2 Steel surface temperature. 17
13.3 Graphical presentation of data . 17
14 Report of the assessment . 17
15 Limits of applicability of the results of the assessment. 18
Annex A (normative) Test method to the smouldering fire or slow heating curve . 22
A.1 General. 22
A.2 Test Conditions. 22
A.3 Termination of the test . 22
A.3.1 Test results. 22
A.4 Evaluation of the results . 23
Annex B (normative) Measurement of properties of fire protection materials . 25
B.1 General. 25
B.2 Thickness of fire protection materials. 25
B.3 Density of applied fire protection materials. 26
B.4 Moisture content of applied fire protection materials. 26
Bibliography . 28

Foreword
This document (prEN 13381-6:2008) has been prepared by Technical Committee CEN/TC 127 “Fire
safety in buildings”, the secretariat of which is held by BSI.
This document is currently submitted to the CEN Enquiry.
This document will supersede ENV 13381-6:2002.
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 89/106/EEC.
This European Standard is one of a series of standards for evaluating the contribution to the fire
resistance of structural members by applied fire protection materials. Other parts of the standard are:
Part 1: Horizontal protective membranes.
Part 2: Vertical protective membranes.
Part 3: Applied protection to concrete members.
Part 4: Applied protection to steel members.
Part 5: Applied protection to concrete / profiled sheet steel composite members.
Part 7: Applied protection to timber members.
Annexes A and B are normative.
Caution
The attention of all persons concerned with managing and carrying out this fire resistance test, is
drawn to fact that fire testing may be hazardous and that there is a possibility that toxic and/or harmful
smoke and gases can be evolved during the test. Mechanical and operational hazards can also arise
during the construction of test elements or structures, their testing and the disposal of test residues.
An assessment of all potential hazards and risks to health shall be made and safety precautions shall
be identified and provided. Written safety instructions shall be issued. Appropriate training shall be
given to relevant personnel. Laboratory personnel shall ensure that they follow written safety
instructions at all times.
The specific health and safety instructions contained within this test shall be followed.

1 Scope
This part of this European Standard specifies a test method for determining the contribution of fire
protection systems to the fire resistance of structural concrete filled hollow steel columns. The
concrete can be lightweight, normal-weight or heavy-weight concrete and of strength classes 20/25
(LC/C/HC) to 50/60 (LC/C/HC).
The method is applicable to all fire protection systems used for the protection of such structural
columns and includes sprayed fire protection, coatings, cladding protection systems and multi-layer or
composite fire protection materials.
The test method and its assessment procedure is designed to permit direct application of the results
to cover a range of thicknesses of the applied fire protection material.
The test method is only applicable to fire protection systems which are fixed directly to the structural
column. Fire protection systems where the fire protection material is not attached directly to the
composite column, leading to a continuous cavity between the column and the fire protection material
of size greater than 5 mm are the subject of prEN 13381-2.
This European Standard contains the fire test which specifies the tests which shall be carried out to
determine the ability of the fire protection system to remain coherent and fixed to the composite
column and to provide data on the temperatures of the outer steel surface of the composite column,
when exposed to the standard time/temperature curve according to the procedures defined herein.
In special circumstances, where specified in national building regulations, there can be a need to
subject reactive protection material to a smouldering curve. The test for this and the special
circumstances for its use are detailed in annex A.
This exposure, applicable to reactive fire protection materials, is used only in special circumstances,
where specified in the national building regulations of a member state of the European Union, and is
not intended to be mandatory for all fire protection materials applied to concrete filled hollow steel
columns.
The fire test methodology makes provision for the collection and presentation of data which can be
used as direct input to the calculation of fire resistance of concrete/steel composite members in
accordance with the procedures given in EN 1994-1-2.
This European Standard also contains the assessment which prescribes how the analysis of the test
data shall be made and gives guidance to the procedures by which interpolation shall be undertaken.
The limits of applicability of the results of the assessment arising from the fire test are defined
together with permitted direct application of the results to different steel/concrete composite columns,
steel types and thicknesses, concrete densities, strengths, thicknesses and production techniques
over the range of thicknesses of the applied fire protection system tested.
2 Normative references
This European Standard incorporates by dated or undated reference, provisions from other publica-
tions. These normative references are cited at the appropriate places in the text, and the publications
are listed hereafter. For dated references, subsequent amendments to or revisions of any of these
publications apply to this European Standard only when incorporated in it by amendment or revision.
For undated references the latest edition of the publication referred to applies (including
amendments).
EN 1363-1, Fire resistance tests – Part 1: General requirements
EN 1363-2, Fire resistance tests – Part 2: Alternative and additional procedures
EN 206- 1, Concrete – Part 1: Specification, performance, production and conformity
EN 1365-4, Fire resistance tests for loadbearing elements – Part 4: Columns
EN 1992-1-1, Eurocode 2: Design of concrete structures – Part 1-1: General rules and rules for
buildings
EN 1994-1-1, Eurocode 4: Design of composite steel and concrete structures –
Part 1-1: General rules and rules for buildings
EN 10210-1, Hot finished structural hollow sections of non-alloy and fine grain structural steels –
Part 1: Technical delivery requirements
ISO 8421-2, Fire protection – Vocabulary – Part 2: Structural fire protection
EN ISO 13943, Fire safety – Vocabulary (ISO 13943:1999)
3 Terms and definitions, symbols and units
3.1 Terms and definitions
For the purposes of this European Standard, the terms and definitions given in EN 1363-1,
EN ISO 13943, ISO 8421-2 and EN 206-1, together with the following, apply.
3.1.1
concrete filled hollow steel column
element of building construction which is loadbearing and is fabricated from an outer hollow steel
column which has been filled with concrete and may or may not contain steel reinforcement within the
concrete
3.1.2
fire protection material
material or combination of materials applied to the outer surface of a concrete filled hollow steel
composite column or the purpose of increasing its fire resistance
3.1.3
passive fire protection materials
materials which do not change their physical form upon heating, providing fire protection by virtue of
their physical or thermal properties. They may include materials containing water which, on heating,
evaporates to produce cooling effects
3.1.4
reactive fire protection materials
materials which are specifically formulated to provide a chemical reaction upon heating such that their
physical form changes and in so doing provide fire protection by thermal insulative and cooling effects
3.1.5
fire protection system
fire protection material together with a prescribed method of attachment to the concrete filled hollow
steel composite column
3.1.6
fire protection
protection afforded to the concrete filled hollow steel composite column by the fire protection system
such that the temperature throughout the depth of the column and upon any steel reinforcing bars
within it is limited throughout the period of exposure to fire
3.1.7
test specimen
concrete filled hollow steel test column plus the fire protection system under test
3.1.8
fire protection thickness
thickness of a single layer fire protection system or the combined thickness of all layers of a multilayer
fire protection system
3.1.9
stickability
ability of a fire protection material to remain sufficiently coherent and in position for a well defined
range of deformations, and furnace and test specimen surface temperatures, such that its ability to
provide fire protection is not significantly impaired
3.1.10
characteristic temperature
surface temperature of the steel outer surface of the concrete filled hollow column which is used for
assessment purposes
3.2 Symbols and units
Symbol  Unit  Designation.
h  mm  Height of the column exposed to heating according to EN 1365-4.
exp
h  mm  Centre to centre distance between the test column supports
sup
(according to EN 1365-4).
h  mm  Height of the test column excluding plates and hinges.
spec
P  kN  Load applied to the concrete filled hollow steel test column.
θ  °C  Critical temperature (as specified in EN 1994-1-2).
crit
4 Test equipment
4.1 General
The furnace and test equipment shall conform to that specified in EN 1363-1.
4.2 Furnace
The furnace shall be designed to permit the dimensions of the test specimen to be exposed to heating
as specified in 5.1 and its installation to be as specified in Clause 7.
4.3 Loading equipment
Loading equipment shall conform to that specified in EN 1363-1. The loading system shall permit
loading, of the magnitude defined in 5.3, to be applied and controlled throughout the test according to
EN 1363-1.
5 Test conditions
5.1 General
Test columns, subjected to predefined loading, are heated in a furnace in vertical orientation, under
specified temperature/time conditions.
Tests are made on loaded and unloaded columns to provide information on:
a) the temperature of the steel surface of the column behind the fire protection system;
b) the ability of the fire protection system to remain attached to the steel surface of the test column
(stickability).
It is recommended that the test be continued until the temperature of the steel surface reaches a
mean value of at least 650 °C (or until any single maximum value of 800 °C is recorded) to give the
necessary information on the stickability of the fire protection system. These temperatures may be
modified if requested by the sponsor.
If the recommended termination temperatures are not reached after 6 hours test duration, the test
shall normally be terminated.
The procedures given in EN 1363-1 and, where appropriate, EN 1363-2 shall be followed in the
performance of this test unless specific contrary instruction is given.
5.2 Support and restraint conditions for columns
The support and restraint conditions employed for the installation of test columns shall be as specified
in EN 1365-4.
Where a pin-joint condition is specified this shall be created according to EN 1365-4.
Where a fully restrained, fixed end, condition is specified this shall be created according to
EN 1365-4.
5.3 Loading conditions
Loading shall be applied to the full size test specimens.
The magnitude and distribution of the load shall produce an eccentrically and axially applied load (P)
which represents 60 % of the design load, for the column in combined compression and uniaxial
bending according to 4.8.3.13 of EN 1994-1-1. The factors, γ = 1 (for both steel and concrete), a
M
buckling length equal to h and those actual material properties defined in 6.5 shall be used in the
sup
calculation of the load to be applied.
6 Test specimens
6.1 Number of test specimens
At least one loaded full size composite test column with the minimum thickness of applied fire
protection system and one unloaded small size test column with the maximum thickness shall be
tested. If the system is only available in one thickness, then the full size loaded test only shall be
carried out, at that thickness and the applicability of the result restricted.
Additional unloaded small size columns may be tested with the fire protection system applied at
intermediate thicknesses or to other sizes of cross-section (within the same cross-section shape only)
in order to provide temperature data which may be used for direct application purposes.
Two unloaded small size test columns, one with the maximum and one with the minimum thickness of
applied fire protection system is used when the test is carried out to the smouldering curve, according
to annex A (unless the material is available in one thickness only).
6.2 Size of test specimens
The size of the test columns or specimens shall be as specified in Table 1 and exemplified in
Figure 1.
Table 1 — Sizes of test specimens
small specimen large specimen
1)
Exposed height h (mm)
≥ 5 times φ (1 000 min) ≥ 3 000
exp
2)
Height of column h (mm) Not applicable h < (h + 600)
sup sup exp
1)
The size of small test column shall be ≥ 5 times the equivalent diameter (φ) of its circular
cross-section or ≥ 5 times the smallest cross-sectional dimension if square or rectangular.

2)
This additional length beyond the supports and required for installation purposes shall be
as specified in EN 1365-4 and kept as small as possible.

6.3 Construction of test specimens
6.3.1 Construction of concrete filled hollow steel test columns
The concrete filled hollow steel composite test column shall comprise a square steel hollow section of
size (150 to 160) mm × (150 to 160) mm or a circular column of (160 to 170) mm diameter. The
thickness of the steel will normally be the minimum available.
Both large and small hollow steel test columns shall contain at least two 20 mm diameter holes (one
at either end) for steam venting (see Figure 1). The hollow steel test columns shall be filled with
concrete to the composition specified in 6.4.2.
Steel plates of area greater than the cross-sectional area of the test column and its applied fire
protection system, by at least 10 mm in every direction and 20 mm approximate thickness shall be
welded to both the top and the bottom of both large and small test columns, after the column is
conditioned and before testing.
6.3.2 Application of the fire protection system to the composite test column
The steel surface of the composite test column shall be prepared as in practice. The outer steel
surface of the composite test column shall normally be dried prior to the application of the fire
protection system.
The fire protection system shall be uniformly applied to the test column, as in practice, including any
required fixing aids and in the same manner for both maximum and minimum thickness.
The fire protection system shall extend over the full exposed surface of the concrete filled hollow test
column and be applied prior to the application of the test load (if any).
Where a fire protection system creates small cavities between the concrete filled hollow steel test
column and the fire protection material, the ends shall be sealed with fire resistant material to prevent
any flow of hot gases out of the cavities.
Board type fire protection materials shall include joints in accordance with the following:
 large size test column: at least one transverse joint positioned at a distance no further than
500 mm from mid column height;
 small size test column: at least one transverse joint positioned at a distance no further than
100 mm from mid column height.
6.4 Composition of components of test specimen
6.4.1 Hollow steel column
The steel used shall be at least of grade S 235 or comparable grade as defined in EN 10210-1.
6.4.2 Concrete
The concrete in the test specimen shall normally be of type 25/30 to 30/37 [LC/C/HC - (light-weight,
normal-weight or heavy-weight concrete) according to EN 206-1 and EN 1992-1-1], although other
grades within the strength range 20/25 to 50/60 may be used.
The applicability of the results of the assessment arising from the testing of a particular density or
strength of concrete will be restricted according to 15.4 and 15.5.
The concrete shall be prepared from silicious aggregates, of maximum aggregate size of 20 mm, and
Portland cement. The composition and properties of the concrete used shall be appropriate to those
specified in EN 206-1 and EN 1992-1-1.
Other non-silicious and lower density aggregates may be permitted, but the applicability of the results
of the assessment will be restricted according to 15.6.
The consistency of the wet concrete, which shall be poured into the hollow steel column positioned in
vertical orientation, shall be of type S3 or F3 determined in accordance with EN 206-1 to allow for
good compaction and contact with the steel.
6.4.3 Fire protection system
The composition of the fire protection system shall be specified by the sponsor and include, at least,
its expected nominal density, thickness and moisture content. For confidentiality reasons, the sponsor
may not wish detailed formulation or composition details to be reported in the test report. Such data
shall, however, be provided and maintained in confidence in laboratory files.
6.5 Properties of test materials
6.5.1 General
The actual material properties of test specimen component materials shall be determined, according
to EN 1363-1 and using appropriate product test standards, on test materials or test samples
conditioned as defined in Clause 8.
6.5.2 Concrete
The density, moisture content and concrete strength of the concrete component of each concrete
filled hollow steel composite column, shall be measured at intervals throughout the conditioning
process and on the day of test using small representative samples prepared at the same time and
from the same concrete batch as each composite column tested. The method used to prepare these
samples and the means by which they were conditioned shall be reported.
These small samples shall be of the same cross-section (either square or circular) and of similar
(greater than or equal to) dimensions to the steel test column tested. They shall be of 100 mm
thickness. They shall be covered with an impermeable membrane on five sides, the top surface
exposed and conditioned, with the test section, as specified in Clause 8.
The concrete strength shall be measured according to one of the methods specified in EN 206-1. The
test method used shall be reported.
6.5.3 Steel
The grade of steel used in the hollow column shall be confirmed either by measurement to
appropriate standards or by certificate of conformity, which shall be provided by the supplier, against
the specification given in 6.4.1.
6.5.4 Fire protection material
The actual thickness, density and moisture content of the fire protection materials shall be measured
and recorded for each test column at the time of the fire test, either directly upon the fire protection
material itself or upon special samples taken for this purpose. These shall be conditioned as defined
in clause 8. The procedures appropriate to different types of material are given in Annex B.
The thickness of board or panel type fire protection systems shall not deviate by more than 15 % of
the mean value over the whole of its surface. In this case, the mean value shall be used in the
assessment of the results and the limits of applicability of the assessment. If it deviates by more than
15 % the maximum thickness recorded shall be used in the assessment.
The thickness of sprayed or coated passive or reactive fire protection materials shall be measured in
the proximity of each of the thermocouples fixed to the steel surface of the test column beneath the
applied fire protection system. These points are illustrated in Figure 1.
The thickness of sprayed or coated passive or reactive type fire protection systems shall not deviate
by more than 20 % of the mean value over the whole of its surface. In this case, the mean value shall
be used in the assessment of the results and the limits of applicability of the assessment. If it deviates
by more than 20 %, the maximum thickness recorded shall be used in the assessment.
The density of the fire protection material applied to the test columns at maximum and minimum
thickness shall be recorded. The mean value of the density of the fire protection material at maximum
and minimum thickness shall be used in the assessment of the results of the test and in the limits of
applicability of the assessment. If the difference between these is greater than 15 %, then the
maximum recorded density shall be used.
6.6 Verification of the test specimen
An examination and verification of the test specimen for conformity to specification shall be carried out
as defined in EN 1363-1. The properties of the materials used in the preparation of the test specimen
shall be measured as defined in 6.5 using special samples, where necessary, using the methods
defined in Annex B.
The sponsor shall verify that the fire protection material has been applied correctly and in the case of
sprayed or coated materials ensure, by methods appropriate to the material, that it is of the design
composition and specification.
7 Installation of the test construction
7.1 Loaded test column
Loaded test columns shall be mounted vertically in the furnace, with one end pin-jointed and the other
end fully restrained. The extremities of the support of the test column shall be sealed by resilient
material of adequate fire performance to prevent leakage of hot gases during the test. Allowance shall
be made for free expansion of the column and free deformation perpendicular to its longitudinal axis.
The pin-joint shall be accurately located along the axis of the column so as to allow the load to be
applied with a controlled eccentricity (from the vertical column axis) of h /500 mm or 7 mm
sup
maximum.
7.2 Unloaded specimen
Short test columns shall be mounted vertically to the underside of the furnace cover slab or stood on
the furnace floor, either directly or on plinths.
A slab of ceramic fibre (or equivalent material) thermal insulation board of thickness (10 ± 1) mm and
density (350 ± 50) kg/m shall be used between all contact surfaces of the column and the cover slab
or the furnace floor or plinth. The linear dimensions of this shall be greater than the total overall
dimensions of the column test specimen.
The exposed ends of unloaded short column test specimens shall be protected with thermal insulation
board, or similar, which at elevated temperatures is capable to provide an equivalent thermal
insulation to at least 5 times that of the particular thickness of the fire protection material applied over
the length of the column.
8 Conditioning of the test construction
The test construction and test samples taken for the determination of material properties (specified in
6.5) shall be conditioned according to EN 1363-1. Material properties shall be determined according
to methods specified in 6.5, EN 1363-1 and Annex B.
The minimum recommended conditioning time for concrete filled hollow steel columns is 90 days.
9 Application of instrumentation
9.1 General
The instrumentation for the measurement of temperature, furnace pressure and deformation shall
comply with the requirements of EN 1363-1.
9.2 Instrumentation for the measurement of furnace temperature
Plate thermometers of the type specified in EN 1363-1 shall be provided for the measurement of the
furnace temperature and shall be uniformly distributed as given in EN 1365-4, to give a reliable
indication of the temperature in the region of the test column.
The location of the plate thermometers when testing unloaded columns shall be identical to those
used for the loaded column, however two only shall be used, both located at mid column height.
9.3 Instrumentation for measurement of test specimen temperature
9.3.1 General
For large loaded test columns, thermocouples shall be provided to permit temperature to be recorded
at five uniformly spaced measuring stations, the highest and lowest being 500 mm from the exposed
ends of the column, as shown in Figure 1.
For small unloaded test columns, thermocouples shall be provided at two measuring stations only,
located at 1/3 and 2/3 column height.
All thermocouples for the measurement of the test specimen temperature shall be of the double glass
fibre insulated bare wire type specified in EN 1363-1 and be positioned and fixed as specified in
EN 1363-1.
9.3.2 Mandatory thermocouples
At each measuring station there shall be situated four thermocouples fixed on the outer steel surface
of the test column, beneath the fire protection material.
9.3.3 Optional thermocouples
Optional thermocouples (at least two in number) may be introduced into the body of the concrete,
within the steel tube. Such thermocouples shall be mounted using a thermocouple spacer grid,
comprising 6 mm diameter steel bars to which the thermocouples are attached, so as to guarantee
their positioning. The thermocouples shall be fixed to the 6 mm bars isothermally throughout their
length. The hot junction shall be angled away from the bar such that it is between 5 mm to 10 mm
away from the surface of the bar and positioned accurately at the required depth.
To provide protection against damage when casting concrete, such thermocouples may be encased
within a secondary casing, which shall be chosen such that it will not affect the temperature history of
the thermocouple throughout the test.
The data derived from these may be used for extended application purposes.
9.4 Instrumentation for measurement of pressure
Equipment for measuring pressure within the furnace shall be provided, located and used as specified
in EN 1363-1.
9.5 Instrumentation for measurement of deformation
A suitable means of measuring the vertical deformation of the test specimen at mid-span, relative to
the supports, shall be provided, located and used as specified in EN 1363-1 for loaded test
specimens.
9.6 Instrumentation for measurement of applied load
Instrumentation for the measurement of applied load to loaded test specimens shall be provided and
used as specified in EN 1363-1.
10 Test procedure
10.1 General
Carry out checks for thermocouple consistency and establish data points for temperature as specified
in EN 1363-1 before commencing the test and the procedures defined in 10.2 to 10.7.
10.2 Furnace temperature and pressure
Measure and record the furnace temperature using the thermocouples described in 9.2 and the
furnace pressure in accordance with the procedures and frequency specified in EN 1363-1.
Control the furnace temperature according to the data received from the furnace temperature
measurement thermocouples to the criteria of EN 1363-1.
Control the furnace pressure to the criteria of EN 1363-1.
10.3 Application and control of load
Using the procedures of EN 1363-1, apply a constant load to the large test column, of magnitude and
distribution in accordance with 5.3 throughout the test period until the final column length, having
reached a maximum length and then undergone contraction, returns to its original length, i.e. the zero
point for axial deformation. At this point the load shall be removed.
10.4 Temperature of test specimen
Measure and record the temperature of the steel surface of the test column and within the concrete
(optional), using the thermocouples specified in 9.3, at intervals not exceeding 1 min.
10.5 Deformation
Using the procedures of EN 1363-1, for the large loaded test column, identify an initial deformation
datum point, relative to the supports, before application of the load. Then apply the test load and
measure the zero point for axial deformation after applying the load and before commencement of
heating. Monitor the axial deformation of the test column continuously throughout the test and record
the results at intervals not exceeding 1 min.
10.6 Observations
Wherever practical, monitor the general behaviour of the test column, especially the fire protection,
throughout the test and record the occurrence of cracking, fissuring, deterioration, detachment or
similar behaviour as described in EN 1363-1.
10.7 Termination of test
Terminate the test when the temperature of the steel surface reaches a mean value of at least 650 °C
(or when any single maximum value of 800 °C is recorded) or any agreed higher value at the request
of the sponsor, especially if the zero point for axial deformation has not yet been regained.
If the recommended termination temperature is not reached after 6 h test duration, then the test shall
normally be terminated. Otherwise terminate the test when one or more of the reasons for termination
specified in EN 1363-1 occurs.
11 Test results
11.1 Acceptability of test results
It is possible that within any test apparently erroneous results may occur through failure of
thermocouple
...