ISO 15835-2:2018

INTERNATIONAL ISO
STANDARD 15835-2
Second edition
2018-10
Steels for the reinforcement of
concrete — Reinforcement couplers
for mechanical splices of bars —
Part 2:
Test methods
Aciers pour l'armature du béton — Coupleurs d'armature destinés
aux raboutages mécaniques de barres —
Partie 2: Méthodes d'essai
Reference number
©
ISO 2018
© ISO 2018
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Published in Switzerland
ii © ISO 2018 – All rights reserved

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols . 1
5 Testing of mechanical splices . 2
5.1 General . 2
5.2 Preparation of test pieces . 2
5.3 Tensile test . 3
5.3.1 General. 3
5.3.2 Testing equipment . 3
5.3.3 Test procedure . 3
5.3.4 Failure mode and location . 4
5.4 Slip test . 4
5.4.1 General. 4
5.4.2 Testing equipment . 4
5.4.3 Test procedure . 4
5.4.4 Evaluation of slip under Option 1 as defined in ISO 15835-1 . 5
5.4.5 Evaluation of slip under Option 2 as defined in ISO 15835-1 . 5
5.5 High-cycle fatigue test . 6
5.5.1 Principle of the test . 6
5.5.2 S-N diagram . 6
5.6 Low-cycle loading test . 7
5.7 Identification and marking . 8
6 Test report . 8
Foreword
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.org/iso/foreword .html.
The committee responsible for this document is ISO/TC 17, Steel, Subcommittee SC 16, Steels for the
reinforcement and prestressing of concrete.
This second edition cancels and replaces the first edition (ISO 15835-2:2009), which has been
technically revised with changes made to Clauses 5 and 6, 5.2, 5.4 and 5.6 and Table 1. The figures have
been revised and renumbered.
A list of all the parts in the ISO 15835 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/members .html.
iv © ISO 2018 – All rights reserved

INTERNATIONAL STANDARD ISO 15835-2:2018(E)
Steels for the reinforcement of concrete — Reinforcement
couplers for mechanical splices of bars —
Part 2:
Test methods
1 Scope
This document specifies test methods applicable to couplers for mechanical splices of steel
reinforcing bars.
This document is applicable to the various standards for steel reinforcing bars as well as the various
reinforced concrete design standards.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 6892-1:2016, Metallic materials — Tensile testing — Part 1: Method of test at room temperature
ISO 9513, Metallic materials — Calibration of extensometer systems used in uniaxial testing
ISO 15630-1, Steel for the reinforcement and prestressing of concrete — Test methods — Part 1: Reinforcing
bars, wire rod and wire
ISO 15835-1, Steels for the reinforcement of concrete — Reinforcement couplers for mechanical splices of
bars — Part 1: Requirements
ISO 16020, Steel for the reinforcement and prestressing of concrete — Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 15835-1 and ISO 16020 apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https: //www .iso .org/obp
— IEC Electropedia: available at http: //www .electropedia .org/
4 Symbols
Table 1 — Symbols
Symbol Unit Designation
A % Percentage total elongation at maximum tensile force, F
gt max
d mm Nominal diameter of the reinforcing bar
a
E MPa Nominal modulus of elasticity of the reinforcing bar
a 2
1 MPa = 1 N/mm .
Table 1 (continued)
Symbol Unit Designation
L mm Length of mechanical splice as defined in ISO 15835-1
L mm Coupler length
L mm Gauge length for the measurement of slip
g
L mm Gauge length for conducting the low-cycle loading test
N — Specified number of load cycles in high-cycle fatigue test
Specified characteristic (or nominal) yield strength value of the
R MPa
eH, spec
reinforcing bar
ΔL mm Calculated elastic elongation of an unspliced bar
e
Total elongation of the spliced bar measured as elongation of the
ΔL mm
g
gauge length
ΔL mm Slip of the mechanical splice
s
ΔL mm Gauge length extension under load
t
ε % Strain at nominal yield strength
y
2σ MPa Stress range for high-cycle fatigue test
a
σ MPa Upper stress in the axial load fatigue test
max
σ MPa Lower stress in the axial load fatigue test
min
a 2
1 MPa = 1 N/mm .
5 Testing of mechanical splices
5.1 General
The test methods covered by this document are as follows:
a) tensile test (see 5.3);
b) slip test (see 5.4);
c) high-cycle fatigue test (see 5.5);
d) low-cycle loading test (see 5.6).
A reference bar shall always be tested in the case of qualification testing and continuous independent
testing, for each test except the fatigue test. The reference bar shall be taken from the same length of
reinforcing bar as used in the test splice. Where different diameters are used in a splice, the reference
bar shall be taken from the smaller bar diameter of the splice.
For the calculation of stresses, the nominal cross-sectional area of the reinforcing bar shall be used.
For couplers with adjustable length, splices should be tested at their maximum extension in accordance
with the manufacturer’s instructions.
The temperature in the testing laboratory should be between 10 °C and 30 °C.
5.2 Preparation of test pieces
All tests shall be performed on mechanical splices prepared and assembled in the same manner as they
are prepared for normal use, according to written installation instructions from the supplier of the
coupler. The installation instruction documents for the coupler shall be made available to the testing
laboratory.
The coupler shall be positioned approximately in the middle of the test piece.
2 © ISO 2018 – All rights reserved

The test piece for the tensile test shall be sufficiently long to ensure a free length between the grips
of the testing machine to allow the determination of A . The minimum sufficient free length of the
gt
test piece for the tensile test is 400 mm + L, where L is the length of mechanical splice (as defined in
ISO 15835-1). The length L for determining A shall, for both bars, be located outside the length of the
3 gt
mechanical splice (as defined in ISO 15835-1). This free length may, however, be reduced if the stroke
of the testing machine is too short to accommodate the test piece, as long as it remains possible to
measure A over the gauge length specified in ISO 15630-1.
gt
The test piece for the slip test may have a shorter free length than the test piece for the tensile test.
However, the free length shall not be less than 250 mm + L.
The test pieces for the fatigue tests shall be sufficiently long to ensure a free length between the grips
of the testing machine, which is larger than the length of the mechanical splice.
The geometry for the measurement of elongations is shown in Figure 1.
Key
F applied force
L length of the mechanical splice (as defined in ISO 15835-1)
L coupler length
L 2d where d is the nominal diameter of the reinforcing bar
L minimum free length for the measurement of A (as defined in ISO 15630-1)
3 gt
L gauge length for the measurement of slip
g
Figure 1 — Definition of lengths for measuring elongations of the mechanical splice
5.3 Tensile test
5.3.1 General
The strength and ductility are determined by means of a tensile test. The test pieces from the slip test
may be used for this test.
5.3.2 Testing equipment
The testing equipment shall conform to ISO 15630-1.
5.3.3 Test procedure
The test shall be performed in acco
...