EN 12697-48:2021

SLOVENSKI STANDARD
01-januar-2022
Bitumenske zmesi - Preskusne metode - 48. del: Zlepljenost plasti
Bituminous mixtures - Test methods - Part 48: Interlayer Bonding
Asphalt - Prüfverfahren - Teil 48: Schichtenverbund
Mélanges bitumineux - Méthodes d'essai - Partie 48: Lien de couches
Ta slovenski standard je istoveten z: EN 12697-48:2021
ICS:
93.080.20 Materiali za gradnjo cest Road construction materials
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 12697-48
EUROPEAN STANDARD
NORME EUROPÉENNE
November 2021
EUROPÄISCHE NORM
ICS 93.080.20
English Version
Bituminous mixtures - Test methods - Part 48: Interlayer
Bonding
Mélanges bitumineux - Méthodes d'essai - Partie 48: Asphalt - Prüfverfahren - Teil 48: Schichtenverbund
Lien de couches
This European Standard was approved by CEN on 16 August 2021.

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-CENELEC 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-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 12697-48:2021 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 4
4 Principle . 5
4.1 General . 5
4.2 Torque Bond Test (TBT) . 5
4.3 Shear Bond Test (SBT). 6
4.4 Tensile Adhesion Test (TAT) . 6
5 Specimens . 6
6 Torque Bond Test (TBT) . 7
6.1 Apparatus . 7
6.2 Materials . 7
6.3 Site test method . 7
6.4 Laboratory test method . 8
6.5 Calculation of Torque Bond Strength and expression of results . 9
6.6 Visual assessment of the mode of failure . 9
6.7 Test report .10
6.8 Precision .10
7 Shear Bond Test (SBT).11
7.1 Apparatus .11
7.2 Specimens .12
7.3 Test procedure .13
7.4 Calculation and Expression of Results .14
7.5 Test report .16
7.6 Precision .16
8 Tensile Adhesion Test (TAT) .17
8.1 Apparatus .17
8.2 Materials .18
8.3 Specimen .18
8.4 Test procedure .19
8.5 Calculation and expression of results .20
8.6 Test report .20
8.7 Precision .21
Annex A (informative) Compressed Shear Bond Test (CSBT) .22
Annex B (informative) Alternative Shear Bond Test (ASBT) .31
Annex C (informative) Layer Adhesion Measuring Instrument (LAMI) .34
Bibliography .45

European foreword
This document (EN 12697-48:2021) has been prepared by Technical Committee CEN/TC 227 “Road
materials”, 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 May 2022, and conflicting national standards shall be
withdrawn at the latest by May 2022.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
A list of all parts in the EN 12697 series can be found on the CEN website.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia,
Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland,
Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North
Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United
Kingdom.
1 Scope
This document specifies test methods for determining the bond strength between an asphalt layer and
other newly constructed construction layers or existing substrates in road or airfield pavements. The
tests can also be applied on laboratory prepared interlayers.
The normative tests described in this document are:
— Torque Bond Test (TBT), generally applicable to any layer thicknesses;
— Shear Bond Test (SBT), generally applicable to layer thicknesses > 15 mm;
— Tensile Adhesion Test (TAT), generally applicable to layer thicknesses ≤ 15 mm.
NOTE Further non normative test methods are described in informative annexes:
— Annex A (informative) - Compressed Shear Bond Test (CSBT);
— Annex B (informative) - Alternative Shear Bond Test (ASBT);
— Annex C (informative) - Layer Adhesion Measuring Instrument (LAMI).
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.
EN 12697-27, Bituminous mixtures — Test methods — Part 27: Sampling
EN 12697-29, Bituminous mixtures — Test methods — Part 29: Determination of the dimensions of a
bituminous specimen
EN 12697-33, Bituminous mixtures — Test methods — Part 33: Specimen prepared by roller compactor
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
• IEC Electropedia: available at https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
3.1
peak shear stress of the interface
τ
SBT,max
maximum value of shear stress [MPa] determined as the maximum force F divided by the initial cross
sectional area A, of a specimen when tested as described in this document
3.2
displacement at peak shear stress
δ
SBT,max
displacement at the maximum value of shear stress of a specimen when tested as described in this
document
3.3
shear stiffness modulus
k
SBT,max
slope of the shear stress versus displacement - graph determined from the linear part of the graph
3.4
effective cross sectional area
value of the effective contact area between the two layers of the specimen
Note 1 to entry: This area can be expressed as a function of the relative displacement of the two portions of the
specimen as shown in Figure A.3.
3.5
dilatancy
ratio between the difference of the last two current recorded values of the vertical and the horizontal
displacement [d = (η - η )/(δ - δ )] of a specimen when tested as described in Annex A
i i-1 i i-1
3.6
normal stress
ratio between the normal load and the effective cross sectional area of a specimen when tested as
described in Annex A
3.7
critical condition
shearing of the interface in residual (pure friction) condition at constant volume of a specimen when
tested as described in Annex A
4 Principle
4.1 General
The described test methods simulate different loading conditions and are applicable on different bonds
between road construction layers. The methods give different results because they measure different
failure modes.
4.2 Torque Bond Test (TBT)
The torque bond test assesses the resistance to horizontal shear stress:
• The torque bond test is suitable for testing the bond strength between road layers in laboratory and
in situ;
• The torque bond test assesses the resistance to the stresses generated primarily by traffic
accelerating or braking, but also by different thermal movements when the layers are of different
materials;
• The torque bond test can be carried out immediately after laying;
• The torque bond test can be applied to assess the interlayer bond quality of bond coats or tack coats.
When the thickness of the top layer above the interlayer assessed is less than 15 mm, the torque bond
test can be applied for evaluating the durability of the top layer.
The torque bond test is carried out either in situ or in the laboratory using cores. A circular steel plate is
glued to the top road surface in situ or on top of a core in a laboratory. A rotational horizontal force is
applied to the steel plate and the torque moment is measured. For a top layer with a thickness < 15 mm,
the steel plate is glued on top of the surface or – for the laboratory test method – a core that is larger than
the plate diameter. For a top layer with a thickness ≥ 15 mm, a cylindrical groove of the same dimension
as the plate is cut through the upper layer down into the bottom layer.
4.3 Shear Bond Test (SBT)
The shear bond test assesses the resis
...