EN 1052-5:2005
(Main)Methods of test for masonry - Part 5: Determination of bond strength by the bond wrench method
Methods of test for masonry - Part 5: Determination of bond strength by the bond wrench method
This document specifies a method for determining the bond strength of horizontal bed joints in masonry using a bond wrench.
Guidance is given on the preparation of the specimens, the conditioning required before testing, the testing equipment, machine, the method of test, the method of calculation and the contents of the test report.
Prüfverfahren für Mauerwerk - Teil 5: Bestimmung der Biegehaftzugfestigkeit
Dieses Dokument legt ein Verfahren zur Bestimmung der Biegehaftzugfestigkeit von horizontalen Lagerfugen in Mauerwerk fest.
Es enthält Anleitungen für die Herstellung der Prüfkörper, die vor der Prüfung erforderliche Konditionierung, die Prüfeinrichtung, die Prüfmaschine, das Prüfverfahren, das Berechnungsverfahren und den Inhalt des Prüfberichtes.
Méthodes d'essai de la maçonnerie - Partie 5 : Détermination de la résistance à la rupture d'un joint de muret selon la méthode du moment de flexion en tête de muret
La présente Norme européenne décrit une méthode de détermination de la résistance à la rupture de joints d'assises horizontaux dans la maçonnerie par application d'un moment de flexion en tête du muret.
Des indications sont données sur la préparation des corps d'épreuve, le conditionnement nécessaire avant l'essai, l'appareillage d'essai, la machine, la méthode d'essai, la méthode de calcul et le contenu du rapport d'essai.
Metode preskušanja za zidovje – 5. del. Ugotavljanje sprijemne trdnosti z metodo „bond wrench“
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
01-junij-2005
Metode preskušanja za zidovje – 5. del. Ugotavljanje sprijemne trdnosti z metodo
„bond wrench“
Methods of test for masonry - Part 5: Determination of bond strength by the bond wrench
method
Prüfverfahren für Mauerwerk - Teil 5: Bestimmung der Biegehaftzugfestigkeit
Méthodes d'essai de la maçonnerie - Partie 5 : Détermination de la résistance a la
rupture d'un joint de muret selon la méthode du moment de flexion en tete de muret
Ta slovenski standard je istoveten z: EN 1052-5:2005
ICS:
91.080.30 Zidane konstrukcije Masonry
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN STANDARD
EN 1052-5
NORME EUROPÉENNE
EUROPÄISCHE NORM
April 2005
ICS 91.080.30
English version
Methods of test for masonry - Part 5: Determination of bond
strength by the bond wrench method
Méthodes d'essai de la maçonnerie - Partie 5: Prüfverfahren für Mauerwerk - Teil 5: Bestimmung der
Détermination de la résistance à la rupture d'un joint de Biegehaftzugfestigkeit
muret selon la méthode du moment de flexion en tête de
muret
This European Standard was approved by CEN on 14 February 2005.
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 Central Secretariat 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 Central Secretariat has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,
Slovenia, Spain, Sweden, Switzerland and United Kingdom.
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COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36 B-1050 Brussels
© 2005 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 1052-5:2005: E
worldwide for CEN national Members.
Contents Page
Foreword. 3
1 Scope. 4
2 Normative references . 4
3 Principle . 4
4 Terms, definitions and symbols . 4
5 Materials. 6
6 Apparatus . 6
7 Preparation and curing of specimens. 8
8 Procedure . 9
9 Measurements and observations. 10
10 Replications. 10
11 Calculations. 10
12 Evaluation of results. 11
13 Test report . 12
Annex A (normative) Failure modes which provide a valid bond strength result. 13
Bibliography . 15
Foreword
This document (EN 1052-5:2005) has been prepared by Technical Committee CEN/TC 125
"Masonry", the secretariat of which is held by BSI.
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 2005, and conflicting national standards
shall be withdrawn at the latest by October 2005.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy,
Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia,
Spain, Sweden, Switzerland and United Kingdom.
1 Scope
This document specifies a method for determining the bond strength of horizontal bed joints in
masonry using a bond wrench.
Guidance is given on the preparation of the specimens, the conditioning required before testing, the
testing equipment, machine, the method of test, the method of calculation and the contents of the test
report.
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 772-1, Methods of test for masonry units — Part 1: Determination of compressive strength
EN 772-10, Methods of test for masonry units — Part 10: Determination of moisture content of
calcium silicate and autoclaved aerated concrete units
EN 998-2, Specification for mortar for masonry — Part 2: Masonry mortar
EN 1015-3, Methods of test for mortar for masonry — Part 3: Determination of consistence of fresh
mortar (by flow table)
EN 1015-7, Methods of test for mortar for masonry — Part 7: Determination of air content of fresh
mortar
EN 1015-11, Methods of test for mortar for masonry — Part 11: Determination of flexural and
compressive strength of hardened mortar
3 Principle
The bond strength of masonry by the bond wrench method is derived from the strength of small
masonry specimens tested to destruction. The specimen is rigidly held and a clamp is applied to the
top unit. A bending moment is applied to the clamp by a lever until the top unit is pulled from the
remainder. The characteristic value, calculated from the maximum stresses achieved by the samples
is considered to be the bond strength of the masonry.
4 Terms, definitions and symbols
For the purposes of this document, the following terms and definitions apply.
4.1
masonry
assemblage of masonry units laid in a specified pattern and jointed together with mortar
4.2
bond strength
strength of a masonry specimen when subjected to a locally applied normal force and bending
moment so as to remove a single unit from the specimen
4.3
hydraulic cement mortar
mortar with cement or cement and air-lime as the binder where the mass of air lime does not exceed
50 % of the total binder mass
4.4
lime based mortar
mortar with cement and air-lime as the binder where the mass of cement does not exceed 50 % of the
total binder mass
4.5
air-lime
limes mainly consisting of calcium oxcide or hydroxide which slowly harden in air by reacting with
atmospheric carbon dioxide. Generally they do not harden under water as they have no hydraulic
properties
4.6 Symbols
e distance from the applied load to the tension face of the specimen in mm
e
distance from the centre of gravity of the lever and upper clamp from the tension face
of the specimen in mm
W weight of masonry unit pulled of the specimen and any adherent mortar in N
F applied load in N
F
weight of the bond wrench in N
f individual bond strength in N/mm
wi
f
mean bond strength in N/mm
w
f characteristic bond strength in N/mm
wk
d
mean depth of the specimen in mm
b mean width of the bed joint tested in mm
Y logarithm of the individual bond strength (f )
i wi
Z section modulus of the projected plan area of the failure surface in mm
n
number of individual values
s standard deviation of the logarithmic values
k numerical factor
5 Materials
5.1 Masonry units
5.1.1 Conditioning of the units
Record the method of conditioning the masonry units prior to laying. Measure the moisture content by
mass of autoclaved aerated concrete and calcium silicate units in accordance with EN 772-10. For
other types of masonry unit, record the method of conditioning the units prior to laying. Record the
age of non-autoclaved concrete units at the time of testing the masonry specimens.
5.1.2 Testing
Determine the compressive strength of a sample of masonry units, using the test method given in
EN 772-1. For non-autoclaved concrete units determine the compressive strength at the time of
testing the masonry specimens.
5.2 Mortar
The mortar, its mixing procedure and its flow value shall conform to the requirements of EN 998-2,
unless otherwise specified, and these shall be reported in the test report.
Take representative samples of fresh mortar from the mason’s board to make mortar prism
specimens, to determine the flow value in accordance with EN 1015-3 and to determine the air
content in accordance with EN 1015-7. Determine the mean compressive strength at the time of
testing the masonry specimens in accordance with EN 1015-11.
6 Apparatus
A support frame and clamp which holds in place the unit beneath the top bed joint of the stack bonded
specimen without applying any significant bending moment to any lower units.
A lever which has a clamp at one end which can be applied to the top unit of the stack bonded
specimen. The lever arm should be at least 1 m in length. The tensile stress applied to a specimen
due to the weight of the lever and clamp should not exceed 0,05 N/mm .
A means of applying downward force to the lever arm without shock and a means of measuring this
force with an accuracy of ± 1 %.
An example of a suitable clamping arrangement is shown in Figure 1. The specimen should not be
subjected to any torsional stress, either from the weight of the lever or the applied force. Where highly
perforated bricks with thin shells are to be tested, the faces of the clamp will need to be as large as is
practicable so as to avoid local crushing of the units under the action of the clamping force.
Weighing device capable of weighing a masonry unit to an accuracy of ± 1 %.
Apparatus capable of measuring the dimensions of the specimens to an accuracy of ± 1 mm.
e
e
A
F
F
_
> 10 mm
_
> 10 mm
d
A
Key
1 Specimen
2 Height adjustable
3 Enlargement of area A
Figure 1 — Example of a suitable support frame and clamps
7 Preparation and curing of specimens
7.1 Preparation of masonry specimens
Prepare sufficient specimens such that there are at least ten bed joints available for test. The number
of specimens will depend on the height of the units in order that they can be conveniently handled and
fitted into the test equipment. Examples of suitable specimens are shown in Figure 2. In the case of
very large units it may be necessary to cut them down, if this is necessary ensure that the surfaces
bonded together for testing are the original and not the cut faces. If the units are cut in order to reduce
their length ensure that the bed faces of the cut units have a geometry that is representative of that of
the whole bed face.
A
B
B
A
Stack bonded prism made Couplet made with original units Couplet made with parts of a large
with relatively small units giving 1 result unit (original bed faces are
giving 5 results bonded) giving 1 result
Figure 2 — Examples of suitable specimen formats
NOTE It will usually be necessary to build sufficient specimens to ensure that at least ten results are
available after any have been discarded because the failure was not considered to be a valid result (see
Clause 10 and Annex A).
Build the specimens within 30 min after completion of the conditioning of the units. Use mortar mixed
not more than one hour beforehand unless it is designed to be used over a more prolonged period.
The bearing surfaces of the masonry units shall be wiped clean of any adherent dust. The lower unit
shall be laid on a clean level surface. The next unit shall be laid so that the thickness of the mortar
joint is as specified. The masonry unit shall be checked for linear alignment and level using a
setsquare and spirit level. Excess mortar shall then be struck off with a trowel. Repeat this operation
until the required number of units have been stack bonded.
7.2 Curing and conditioning of the specimens
Immediately after building, pre-compress each specimen using a uniformly distributed mass to give a
-3 2 -3 2
vertical stress between 2,0 × 10 N/mm and 5,0 × 10 N/mm . Then cure the specimens and
maintain them precompressed and undisturbed until testin
...
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