ДСТУ Б EN 846-2:2015
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1 2 4
page 1 2 З? 4 5 6 7 8 9 10 Foreword V
1 Scope 1
2 Normative references 1
3 Principle 2
4 Symbols 2
5 Materials 3
6 Apparatus 3
7 Preparation and storage of test
specimens 5
8 Test Procedure 7
9 Expression of results 8
10 Test report 8
EN 846-2:2000 - - - -
This European Standard 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of an identical text or by endorsement, at the latest by August 2000, and conflicting national standards shall be withdrawn at the latest by August 2000.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom.
This European standard has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association and supports the essential requirements of the EU Construction Products Directive (89/106/EEC) and includes the performance requirements referred to in the Eurocode for masonry Structures.
Part 2. Determination of bond strength of prefabricated bed joint reinforcement in mortar joints
1 2 prEN 771-1 prEN 771-2 prEN 771-3 1 Scope
This European Standard specifies a method for determining the bond strength of prefabricated bed joint reinforcement in a masonry specimen made from specified units and mortar.
This test method is applicable to designed prefabricated bed joint reinforcement complying with prEN 845-3.
The method is not applicable to alternative forms of reinforcement which may be used in masonry, for example bars.
2 Normative references
This European Standard incorporates by dated or undated reference, provisions from other publications. 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.
prEN 771-1 Specification for masonry units - Part 1: Clay masonry units
prEN 771-2 Specification for masonry units - Part 2: Calcium silicate masonry units
prEN 771-3 Specification for masonry units - Part 3: Aggregate concrete masonry units (dense and lightweight aggregates) prEN 771-4 prEN 771-5 prEN 772-1 EN 772-10 prEN 845-3 prEN 998-2 EN 1015-3 EN 1015-7 4 F bk - F mean ~ prEN 771-5 Specification for masonry units - Part 5: Manufactured stone masonry units
prEN 771-6 Specification for masonry units - Part 6: Natural stone masonry units
prEN 772-1 Methods of test for masonry units - Parti: 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
prEN 845-3 Specification for ancillary components for masonry - Part 3: Bed joint reinforcement
prEN 998-2 Specification for mortar for masonry units - 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
prEN 1015-11 Methods of test for mortar for masonry - Part 11: Determination of flexural and compressive strength of hardened mortar
3 Principle
In this test, prefabricated bed joint reinforcement is embedded in mortar in a small wall of bonded masonry units. The reinforcement is then subjected to tension in order to determine its bond strength.
4 Symbols
F bk is the characteristic load capacity of the bed joint reinforcement, (N)
F mean is the mean load capacity of the bed joint reinforcement, (N)
F x(1
s - 5 5.1 5.1.1 5.1.2 5.2 6 6.1 s is the standard deviation of the log normal values for n-1 degrees of freedom
k is a numerical factor
n is the number of specimens
5 Materials
5.1 Masonry units
5.1.1 Conditioning
The conditioning of masonry units shall be as specified:
Record the method of conditioning the units prior to laying. Measure the moisture content by mass of autoclaved aerated concrete and calcium silicate masonry units in accordance with EN 772-10. 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 method given in prEN 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 prEN 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 prisms to determine the flow value in accordance with EN 1015-3, and to determine the air content in accordance with EN 1015-7. Use the prism specimens to determine the mean compressive strength at the time of testing of the masonry specimens in accordance with prEN 1015-11.
6 Apparatus
6.1 A simple support for holding the test specimen such that the reaction is as close as possible to the centre line of the applied load.
6.2 6.3 6.2 A means of applying and maintaining on the test specimen a measured compressive load providing a stress of between 0,05 N/mm 2 and 0,1 N/mm 2 , accurate to 6.3 A clamp for gripping the free end of the prefabricated bed joint reinforcement and transmitting the load.
NOTE: A possible arrangement is shown in figure 1. Ideally the clamp should have serrated grooves for the wires to lay in and the force should be applied using a small hydraulic ram.
6.4 6.5 7 7.1 7.2 (1) (2) 6.4 A test system with a suitable load capacity. The load shall be measured using a device having a maximum error of 2 % of the full scale reading. The read-out shall be such that the maximum load reading or the reading at a specimen displacement of 0,1 mm whichever is the lesser, occurs above 20 % of the full scale reading.
6.5 A displacement measuring device with a range of 10 mm and a maximum measuring error of 0,01 mm.
7 Preparation and storage of test specimens
7.1 General
At least five specimens of prefabricated bed joint reinforcement shall be tested.
7.2 Preparation
Masonry specimens shall be constructed as specified incorporating a representative length of the prefabricated reinforcement. The representative length shall be taken to be:
(1) For truss type reinforcement, one complete length of the diagonal cross wire of the reinforcement (0,5b) plus 0,05b additional embedment at either end
(2) For ladder-type reinforcement, a length containing one cross wire of the reinforcement as shown in figure 2.
The width of the specimen shall be chosen so as to allow a minimum of 10 mm and a maximum of 50 mm lateral cover to both longitudinal wires.
Products designed to be used in cavity or shell bedded masonry shall be tested in an appropriate specimen as shown in figure 3.
The specimen shall be constructed in and mortared up to a jig with a flat horizontal base surface and an upstand such that the reaction faces are flat and perpendicular to the axis of the reinforcement. Measure and record the thickness of the mortar joint.
2 - З? - 4 - 5 - 6 - 7 - 8 - 9 - Length of one cycle of the reinforcement
Packing mortar
Loading clamp
Precompression platens
Load cell to measure the precompression force
Small wall specimen
Clamp
Displacement measuring device a
Figure 3 - Specimens for (a) divided joints and (b) cavity walls, showing only the lower layer of units and the position of the mortar layer (hatched)
7.3 8 8.1 8.2 8.3 7.3 Storage
Take appropriate steps to prevent the test specimen from drying out during the first three days after construction, e.g. by covering with polyethylene sheets, and then leave uncovered in a laboratory environment until tested. Use a curing period of 7 days for thin layer mortars and 28 days for general purpose mortars.
8 Test Procedure
8.1 Placing the specimen in the test machine
At the end of the curing period place the specimens in the test machine such that the wire is axial and aligned at the centre of action of the test system.
8.2 Test environment
Carry out the tests at ambient laboratory temperature.
8.3 Loading
Apply the specified precompression load. Apply the tensile load smoothly, at the rates given in table 1. Record the complete load displacement curve, the maximum load and the mode of failure. Acceptable modes of failure are (1) one wire breaks, (2) both wires break, (3) wires pull out. If the mortar pulls out or the masonry splits the result shall be discarded and further specimens shall be tested until at least five results are obtained. Table 1 - Maximum loading rates and increments
Record the load capacity of each specimen, being the maximum load achieved or the load to cause a 1 mm deflection, whichever is the lesser. 9 Ft *~~CT‘
b) mens:
F x1 ... F& ... F x3 ... F xn lo gio F xn yy
Ymean = s - n - Table 2 - Relation between F bk = anti log 10 (Y c ) H 10 а?) Ь?) с?) Take the characteristic load capacity (F bk ) to be:
F bk = anti log 10 (Y c ) N to the nearest 10 N.
10 Test report
Test reports shall include the following information:
a) the number, title and date of issue of this European Standard;
b) the name of the test laboratory;
c) a description of the prefabricated bed joint reinforcement to prEN 845-3;
d) е?) f) h) і?) j) к?) d) a description of the type of masonry units to the re