CEN/TS 12697-50:2018

SLOVENSKI STANDARD
01-julij-2018
1DGRPHãþD
SIST-TS CEN/TS 12697-50:2016
Bitumenske zmesi - Preskusne metode - 50. del: Odpornost proti površinski obrabi
Bituminous mixtures - Test methods - Part 50: Resistance to scuffing
Asphalt - Prüfverfahren - Teil 50: Widerstand gegen Oberflächenverschleiß
Mélanges bitumineux - Méthodes d'essai - Partie 50 : Résistance aux arrachements
superficiels
Ta slovenski standard je istoveten z: CEN/TS 12697-50:2018
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.

CEN/TS 12697-50
TECHNICAL SPECIFICATION
SPÉCIFICATION TECHNIQUE
May 2018
TECHNISCHE SPEZIFIKATION
ICS 93.080.20 Supersedes CEN/TS 12697-50:2016
English Version
Bituminous mixtures - Test methods - Part 50: Resistance
to scuffing
Mélanges bitumineux - Méthodes d'essai - Partie 50 : Asphalt - Prüfverfahren - Teil 50: Widerstand gegen
Résistance aux arrachements superficiels Oberflächenverschleiß
This Technical Specification (CEN/TS) was approved by CEN on 14 August 2017 for provisional application.

The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to
submit their comments, particularly on the question whether the CEN/TS can be converted into a European Standard.

CEN members are required to announce the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS
available promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in
parallel to the CEN/TS) until the final decision about the possible conversion of the CEN/TS into an EN is reached.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, 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
© 2018 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TS 12697-50:2018 E
worldwide for CEN national Members.

Contents Page
European foreword . 4
Introduction . 6
1 Scope . 7
2 Normative references . 7
3 Terms, definitions, symbols and abbreviations . 7
3.1 Terms and definitions . 7
3.2 Symbols and abbreviations . 8
4 Principle . 8
5 Preparation of test specimens . 9
5.1 General . 9
5.2 Compaction of the slabs . 9
5.3 Dimensions of the specimens . 9
5.4 Age of the specimens . 9
5.5 Dimensions and bulk density of the specimens . 9
6 Loading devices . 10
7 Test results . 10
8 Test report . 12
8.1 General . 12
8.2 Precision . 12
8.2.1 Repeatability . 12
8.2.2 Reproducibility . 12
Annex A (informative) The Aachener Raveling Tester (ARTe) . 13
A.1 Equipment . 13
A.1.1 General . 13
A.1.2 Lateral moving table . 13
A.1.3 Set of rotating wheels . 13
A.1.4 Slab fixation box . 14
A.1.5 Temperature controlled room . 14
A.1.6 Temperature measuring devices . 14
A.1.7 Electric fan (optional) . 15
A.2 Test procedure . 15
Annex B (informative) The Darmstadt Scuffing Device (DSD) . 19
B.1 Equipment . 19
B.1.1 General . 19
B.1.2 Lateral moving table . 19
B.1.3 Test tyre . 19
B.1.4 Asphalt specimen fixture. 19
B.1.5 Heating/temperature . 20
B.1.6 Vacuum wipe-off apparatus . 20
B.1.7 Temperature measurements . 20
B.1.8 Oven . 20
B.2 Test procedure . 20
Annex C (informative) The Rotating Surface Abrasion Test (RSAT) . 23
C.1 General . 23
C.2 Equipment . 23
C.2.1 Motion mechanism . 23
C.2.2 Test tyre . 24
C.2.3 Wheel load and contact pressure. 24
C.2.4 Wheel arm guide . 25
C.2.5 Attachment of the wheel to the wheel arm . 25
C.2.6 Rotation hinge (wheel arm guide) . 25
C.2.7 Slab holder test specimen RSAT . 25
C.2.8 Bearing and rotary axle, consisting of a ring bearer . 26
C.2.9 Braking mechanism . 26
C.2.10 Asphalt specimen fixture . 26
C.2.11 Vacuum wipe-off apparatus . 27
C.3 Test temperature . 27
C.3.1 Heating/temperature . 27
C.3.2 Temperature measurements . 27
C.3.3 Specimen preparation . 27
C.3.4 Performance of the test . 28
Annex D (informative) The Triboroute Device (TRD) . 30
D.1 Equipment . 30
D.1.1 General . 30
D.1.2 Load applicator . 30
D.1.3 Lateral moving table . 31
D.1.4 Asphalt specimen fixture . 31
D.1.5 Heating/temperature . 31
D.1.6 Vacuum wipe-off apparatus . 32
D.2 Test procedure . 32
D.2.1 Specimen preparation . 32
D.2.2 Control of the specimen surface characteristics . 32
D.2.3 Test performance . 33
Bibliography . 35

European foreword
This document (CEN/TS 12697-50:2018) has been prepared by Technical Committee CEN/TC 227
“Road materials”, the secretariat of which is held by DIN.
This document supersedes CEN/TS 12697-50:2016.
In comparison with the previous edition, the following modifications have been made:
— General: Several editorial changes has been performed for clarity and increased consistency of used
terms, definitions, symbols, abbreviations and units. NOTES are amended to normal text were
appropriate;
— The clause numbers for Terms, definitions, symbols and abbreviations [3], [3.1], [3.2] and Principle
[4] has been altered to be in line with current template for standards;
— [3.2] Completion of symbol, D and definition for the diameter of the tested core specimen, in
0,1 mm;
— [3.2] Amended definitions for the following symbols: T, A, M , M , V , V ΔV were “slab” has been
0 1 0 1,
altered to “specimen” since mass and volume parameters are also valid for core specimen;
— [3.2] Amended definition from “loss of volume” to “increase of texture” for the symbol ΔV to be in
line with Clause 7;
— [5.3] Standard dimensions for slabs deleted and transferred to A.1.1 (only valid for ARTe).
Completion with reference to Annexes A to D;
— [5.3] Text describing the variation of thickness of specimen transferred to A.1.1. NOTE describing
preparation of slabs deleted.
— [5.4] NOTE (describing ageing procedures) completed with reference to CEN/TS 12697-52;
— [6] Abbreviations for the listed devices are completed with the full title for clarification;
— [7] Conformity of definition for ΔV to read “increase of texture” for consistency;
— [8] The word “slab” amended to “specimen” were appropriate for consistency;
— [8] bullet f). Completed with alternative report of diameter and thickness of the tested cores;
— [Annexes A to D] Titles completed with respective full title for clarification;
— [Annexes A and B] Amended from (Normative) to (Informative) for consistency. All annexes are
only referred to informatively;
— [A.1.3] Requirement for two smooth unprofiled PIARC tires is replaced by a general requirement of
two smooth profiled 165/75 R14C radial 97/95 tires. NOTE deleted;
— [A.1.3] Tyre pressure corrected from (200 ± 10) kPa to (230 ± 10) kPa;
— [C.2.10] Tolerance for dimension of cores amended from (150 ± 1 mm) to (150 ± 2 mm) for
consistency;
— [C.3.3] New clause (Specimen preparation) introduced for clarity and readbility;
— [C.3.4] New clause (Performance of the test) introduced for clarity and readbility;
nd
— [C.3.4] 2 indent: Thickness of rubber mat changed from (5 ± 1) mm to (3 ± 1) mm;
— [D.1.2] Reference to DIN 53516 deleted. Replaced with clarification that the abrasion resistance for
the tyre is expressed as relative volume loss, in accordance with Method A of ISO 4649 where the
standard reference compound Nr.One is used;
— [D.2.3.1] Bullet a) Incorrect reference to (EN 12697-1). Replaced by (EN 13036-1).
A list of all parts in the EN 12697 series can be found on the CEN website.
This Technical Specification was prepared with the aim of having a 3-year lifetime.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to announce this Technical Specification: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Introduction
The European Committee for Standardization (CEN) draws attention to the fact that it is claimed that
compliance with this document may involve the use of a patent concerning a load applicator given in
subclause D.1.2.
CEN takes no position concerning the evidence, validity and scope of this patent right.
The holder of this patent right has assured CEN that he/she is willing to negotiate licences under
reasonable and non-discriminatory terms and conditions with applicants throughout the world. In this
respect, the statement of the holder of this patent right is registered with CEN. Information may be
obtained from:
IFSTTAR
Allée des Ponts et Chaussées
Route de Bouaye - C S4
44344 Bougeunais France
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights other than those identified above. CEN shall not be held responsible for identifying any or
all such patent rights.
1 Scope
This European Technical Specification specifies a test method for determining the resistance to scuffing
of asphalt mixtures which are used in surface layers and are loaded with high shear stresses in road or
airfield pavement. These shear stresses occur in the contact area between tyre and pavement surface
and can be caused by cornering of the vehicle. Due to these shear stresses, material loss will occur at the
surface of these layers. The test is normally performed on asphalt layers with a high amount of air voids
(e.g. porous asphalt), but can also be applied on other asphaltic mixtures. Test specimens are used
either produced in a laboratory or cut from the pavement.
NOTE The test is developed to determine the resistance to scuffing for noise reducing surface layers where
raveling is the normative damage criterion. The test can also be performed on other surface mixtures with a high
resistance to permanent deformation. In case a mixture has a low resistance to permanent deformation, rutting
can occur during the test. This can influence the test results.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
EN 12697-6, Bituminous mixtures - Test methods for hot mix asphalt - Part 6: Determination of bulk
density of bituminous specimens
EN 12697-29, Bituminous mixtures - Test method for hot mix asphalt - Part 29: Determination of the
dimensions of a bituminous specimen
EN 12697-33, Bituminous mixtures - Test methods for hot mix asphalt - Part 33: Specimen prepared by
roller compactor
3 Terms, definitions, symbols and abbreviations
3.1 Terms and definitions
For the purposes of this document, the following term and definition applies.
3.1.1
material loss
amount of material that has been lost from the surface of the slab due to the test
Note 1 to entry: The amount of material loss can be determined in 3 different ways:
— visually and/or by taking pictures;
— by weighing the mass of the slab before and after the test: the difference in mass per area is a measure for the
resistance to scuffing of the tested asphalt mixture;
— by scanning the surface of the slab before and after the test. The scans provide a 3D picture from the surface
of the slab. After subtracting mathematically the 3D picture after the test from the one before the test, an
accurate 3D overview of the material loss can be generated. The calculated volume of this 3D overview of the
material loss is an accurate value for the resistance to scuffing of the tested asphalt mixture.
Note 2 to entry: If permanent deformation occurs during the test, the results of the surface scan will be
compensated for this phenomenon.
3.2 Symbols and abbreviations
For the purposes of this document, the following symbols and abbreviations apply.
T is the thickness of the specimen, in 0,1 mm;
W is the width of the slab, in 0,1 mm;
L is the length of the slab, in 0,1 mm;
D is the diameter of the tested core specimen, in 0,1 mm;
A is the surface of the tested specimen, in 0,01 mm ;
M is the mass of the specimen before performing the test, in 1 g;
M is the mass of the specimen after performing the test, in 1 g;
ΔM is the loss of mass due to performing the test, in 1 g;
V is the volume of the texture of the specimen before performing the test, in 0,1 mm ;
V is the volume of the texture of the specimen after performing the test, in 0,1 mm ;
ΔV is the increase in the volume of the texture of the specimen due to performing the test, in
0,1 mm .
4 Principle
Laboratory compacted asphalt slabs or asphalt cores cut from a pavement are fixed in a test facility. In
this facility, the asphalt specimen is loaded simultaneously with both normal and shear stresses. Due to
these stresses, material loss will occur from the surface of the specimens. This material loss depends on
the resistance to scuffing of the tested asphalt mixture: the higher the resistance, the less material will
be removed.
To determine the resistance to scuffing, two slabs or (set of) cores shall be tested. The average of both
test results is reported as the resistance to scuffing.
In this Technical Specification, four different kinds of loading facilities are described:
— the Aachener Raveling Tester (ARTe);
— the Darmstadt Scuffing Device (DSD);
— the Rotating Surface Abrasion Test (RSAT); and
— the Triboroute Device (TRD).
5 Preparation of test specimens
5.1 General
To determine the resistance to scuffing of an asphalt mixture, 2 slabs or 2 (sets of) cores of that material
shall be tested. The average of both test results shall be considered to determine the resistance to
scuffing.
5.2 Compaction of the slabs
In the scuffing device, asphalt slabs or (sets of) cores shall be tested. These slabs or (sets of) cores shall
be prepared according to EN 12697-33 or can be cut from pavements.
5.3 Dimensions of the specimens
The test can be performed on specimens with various dimensions defined in Annex A to D. Cores shall
have a standard diameter of (150 ± 2) mm.
5.4 Age of the specimens
Prior to the start of testing, the specimen shall be stored on a flat surface at a temperature of not more
than 20 °C for between 14 days and 42 days from the time of their manufacture. In the case of samples
requiring cutting, the cutting shall be performed no more than 8 days after compaction of the asphalt.
The time of manufacture for these samples is the time when they are cut.
NOTE Not only fresh asphalt mixtures can be tested, also aged specimens can be examined in the scuffing
test. In literature several aging procedures can be found. The choice of a proper aging procedure depends on the
characteristics of the tested material. Guidance for different aging procedures can be found in the technical
specification CEN/TS 12697-52.
5.5 Dimensions and bulk density of the specimens
The dimensions of the slab shall be determined according to EN 12697-29. The length, L, and width, W,
of the slab are measured at four positions of the slab, equally divided over the area. The accuracy of the
measurements shall be 0,1 mm. The average of the four individual measurements are respective the
length, L, and width, W, of the slab.
The thickness, T, of the slab shall be determined at eight points. Each point shall be taken 100 mm from
the edge of the slab using a vernier calliper. All eight point shall be equally divided over the surface of
the slab. The accuracy of each measurement shall be 0,1 mm. The maximum difference between the
eight individual measurements shall be 2,5 mm. If not, the specimen shall not be tested. The average of
the eight measurements is the thickness, T, of the slab.
If cores are tested, the diameter and thickness of each core shall be determined according to
EN 12697-29 using a vernier calliper. The diameter, D, and the thickness, T, are measured at four
positions of the slab, equally divided over the area. The accuracy of the measurements shall be 0,1 mm.
The average of the four individual measurements shall be deemed to be the diameter of the core.
The bulk density of the slab or the core shall be determined according to EN 12697-6 using the bulk
density by dimensions procedure. Before measuring the mass, M0, of the slab, the specimen shall be
dried to constant mass in air at a relative air humidity of less than 80 % at a temperature not more than
20 °C. A test specimen shall be considered to be dry after at least 8 h drying time and when two
weighings performed minimum 4 h apart differ by less than 0,1 %.
6 Loading devices
The resistance to scuffing can be determined using one of the following test devices:
— the Aachener Raveling Tester (ARTe), see Annex A;
— the Darmstadt Scuffing Device (DSD), see Annex B;
— the Rotating Surface Abrasion Test (RSAT), see Annex C; and
— the Triboroute Device (TRD), see Annex D.
7 Test results
The results of the tests shall be reported using the results of the visual inspection and/or pictures
before and after the test and the material loss per covered area (= MLpA). Alternatively, the increase in
texture per covered area, ΔV, can be used. The following formulae shall be used:
— Material loss per covered area MLpA when slabs are tested determine by:
MM−
∆M
0,i 1,i
i
MLpA with i = 1,2 (1)
i
W L W L
ii ii
MLpA
∑
i
i=1
MLpA= (2)
where
M is the mass of the slab i (i = 1,2) before performing the test, in 1 g;
0,i
M1,i is the mass of the slab i (i = 1,2) after performing the test, in 1 g;
W is the width of the slab i (i = 1,2) in 0,1 mm;
i
L is the length of the slab i (i = 1,2) in 0,1 mm.
i
— Material loss per covered area MLpA when a (set of) cores are tested determine:
MM−
∆M
0,i 1,i
i
MLpA with i = 1,2 (3)
i
ππD D
ii
MLpA
∑
i
i=1
MLpA= (4)
where
M is the mass of the (set of) core i (i = 1,2) before performing the test, in 1 g;
0,i
M is the mass of the (set of) core i (i = 1,2) after performing the test, in 1 g;
1,i
D is the diameter of the (set of) core i (i = 1,2) in 0,1 mm.
i
==
==
— Increase in the volume of the texture ΔV per covered area using 3D laser measurements when using
slabs determine:
VV−
1,i 0,i
with i = 1,2 (5)
∆=V
i
W L
ii
∆V
∑
i
i=1
∆=V (6)
where
V is the volume of the texture of the slab i (i = 1,2) before performing the test, in 0,1 mm ;
0,i
V is the volume of the texture of the slab i (i= 1,2) after performing the test, in 0,1 mm ;
1,i
W is the width of the slab i (i = 1,2) in 0,1 mm;
i
Li is the length of the slab i (i = 1,2) in 0,1 mm.
— Increase in the volume of the texture ΔV per covered area using 3D laser measurements when using
(a set of) cores determine:
VV−
1,i 0,i
∆=V with i = 1,2 (7)
i
πD
i
∆V
∑
i
i=1
∆=V (8)
where
V is the volume of the texture of (a set of) cores i (i = 1,2) before performing the test, in
0,i
0,1 mm ;
V is the volume of the texture of (a set of) cores i (i = 1,2) after performing the test, in
1,i
0,1 mm ;
D is the diameter of (a set of) cores i (i = 1,2) in 0,1 mm.
i
Sometimes a substantial part of the scuffing occurs close to the edges of the slab or the core. This
phenomenon especially occurs when course graded porous asphalt specimens are tested. In this
situation, the increase in the volume of the texture can be determined for a smaller area of the slab or
core. If, for example, a slab of 500 mm by 500 mm shows excessive scuffing close to the edges, ΔV can be
determined over an area of 400 mm by 400 mm, skipping the material loss which occurs in the outer
strip with a width of 50 mm of the slab. It is essential to mention the considered area in the report.
8 Test report
8.1 General
The test report shall contain not less than the following information:
a) name of organization carrying out the test;
b) date of the test;
c) reference to this test method and test conditions;
d) characterization and the origin (lab compacted slabs or cut from a pavement) of the tested
material;
e) short description of the test facility.
For each specimen tested, report:
f) length, width and thickness of the tested slab, or diameter and thickness of the tested cores,
expressed to the nearest 0,1 mm;
g) results of the visual inspection of the surface of the specimen before and after the test;
h) mass of the specimen before, M0,i, and after the test, M1,i, expressed to the nearest 1 g;
, expressed to the nearest 1 g/mm ;
i) material loss per covered area MLpAi
j) if available, the volume of the texture of the surface of the specimen before, V and after, V , the
0,i 1,i
test in 0,1 mm ;
k) if available, the increase in the volume of the texture of the surface of the specimen, ΔV , in 0,1 mm .
i
As an average of the two tested slabs per asphalt mixture:
l) general conclusion about material loss, based on the results of the visual inspection of both
specimens;
m) average material loss per covered area, MLpA, expressed to the nearest 1 g/mm ;
n) if available, the average increase in the volume of the texture of the surface of the specimen, ΔV, in
0,1 mm .
8.2 Precision
8.2.1 Repeatability
Currently, repeatability data are not yet available.
8.2.2 Reproducibility
The reproducibility for this test method has not been determined.
Annex A
(informative)
The Aachener Raveling Tester (ARTe)
A.1 Equipment
A.1.1 General
In order to create high shear stresses on the surface of an asphalt slab, a special scuffing device shall be
used. In the Aachener Raveling Tester (ARTe) scuffing device, the slab is fixed in a slab fixation box and
is moving forwards and backwards. This movement shall be created by mounting the slab and the slab
fixation box on a lateral moving table, which is travelling for- and back-wards. During this movement, a
set of two wheel tyres shall rotate over the loading table and the asphalt slab, creating large shear
stresses due to the combination of the lateral movement of the table and the rotation of the wheel set.
NOTE An example of the test facility is given in Figure A.1 and an overview is shown in Figure A.2.
The standard dimensions of the slabs are:
— (500 ± 20) mm by (500 ± 20) mm; or
— (500 ± 20) mm by (320 ± 20) mm.
The thickness of the specimen can vary between 30 mm and 80 mm.
A.1.2 Lateral moving table
The lateral moving table shall consist of a loading frame on wheels which travels over a fixed distance
using rails. By using rails, the table shall move only in one direction.
On the loading frame, on both sides of the specimen, a horizontal surface shall be created. Together with
the slab fixation box and the surface of the slab, a horizontal surface shall be created where the set of
rotating wheels can move around without creating extra vertical dynamic forces due to jumping of the
set of wheels.
The lateral movement of the table shall be realized by using, for example, a belt which is driven by an
electro motor. The speed of the moving table does not need to be constant during the test, so
acceleration and deceleration is possible. However, during the time the set of wheels is travelling over
the slab, the speed of the loading table shall be (0,30 ± 0,03) m/s.
A.1.3 Set of rotating wheels
To create a set of rotating wheels, an electro motor with a vertical axis shall be mounted about mid-
length of the rails on a loading frame. This frame shall consist of two vertical bars which are connected
by a horizontal bar. The connection between the horizontal bar and the two vertical bars shall not be
completely fixed.
Vertical movement of the horizontal bar is allowed and even necessary to be sure that during the test
the set of wheels are always in contact with the asphaltic slab, also when material loss occurs from the
slab.
The vertical axis from the electro motor on the horizontal bar shall have a rotation speed of
(47 ± 1) rpm. In this test, two smooth profiled 165/75 R14C radial 97/95 tires are used.
The tyre pressure shall be (230 ± 10) kPa during the test. Both tyres shall rotate freely when the set of
loading wheels does not touch the lateral moving table. The distance between the centre of both tyres
shall be (460 ± 5) mm, which implies that the total area of the slab that will be loaded during the test.
The total mass of the horizontal bar, electro motor and set of rotating wheels shall be (250 ± 5) kg. To
prevent any loss of vertical forces during the test, the vertical movement of the horizontal bar shall be
as free as possible.
NOTE An example of a cross section of the scuffing device with a set of rotating wheels is given in Figure A.3.
A.1.4 Slab fixation box
The slab shall be built in the lateral moving table in such a way that the surface of the slab and of the
lateral moving table are in one horizontal plane.
NOTE 1 In this way, the variation of the vertical force due to jumping of the set of rotating wheels can be
limited to acceptable values.
To accomplish the correct setting of the asphalt slab in the lateral moving table, the slab shall be fixed in
a slab fixation box.
NOTE 2 To ease the fixation of the slab in the scuffing device, the slab fixation box can be taken from the lateral
moving table. This box consists of a large squared bottom plate and four vertical plates. These plates are fixed
together in such a way that an undeformable box arises.
NOTE 3 An example of a slab fixation box is given in Figure A.4.
The inner dimensions of the box shall be chosen in such a way that the asphalt slab fits easily in the
inner volume of the box. The height of the box shall be chosen so that the surface of the slab fixation box
and the lateral moving table are in one horizontal plane when the slab fixation box is built in in the
lateral moving table.
To be able to test asphalt slabs with various thicknesses, the surface of the asphalt slab shall be in one
horizontal plane with the surface of the lateral moving table. This positioning shall be accomplished by
applying various metal and/or wooden plates with the same surface as the asphalt slab between the
bottom of the slab fixation box and the slab.
At several points in the vertical walls of the slab fixation box, horizontal holes shall be drilled. These
holes shall be provided with screw-threads and bolts. Between the inner walls of the slab fixation box
and the asphalt slab, metal or wooden inlays shall be applied. By regularly tightening all screws, the
asphalt slab shall be complete fixed in the slab fixation box. Attention shall be paid to the fact that the
surface of the inlays between slab and slab fixation box is in one horizontal plane with the lateral
moving table. All vertical planes of the asphalt slab shall be completely supported by the inlays. There
shall be no gap between the asphalt slab and the inlays.
NOTE 4 For tests on dense graded asphalt mixtures, gypsum can be used to fix the slab in the slab fixation box.
A.1.5 Temperature controlled room
The temperature controlled room shall be ventilated and capable of allowing the temperature of the
slab fixation box and the average temperature of the air draught at tens of centimetres from the slab to
be fixed at a temperature of (20 ± 2) °C throughout the duration of the test.
A.1.6 Temperature measuring devices
During the test, the temperature of the slab and tyres shall be measured. These devices shall measure
the temperatures with an accuracy of 1 °C.
NOTE Infrared measuring devices can be used.
A.1.7 Electric fan (optional)
An electric fan can be used during the test to cool the slab and the tyres.
A.2 Test procedure
Before starting the test, the slab and the slab fixation box shall be in the temperature controlled room
for at least 4 h. In this period, both slab and slab fixation box shall meet the requirements with respect
to the test temperature of (20 ± 2) °C. During this acclimatization period, the slab can be mounted in the
slab fixation box. Before mounting the slab, the dimensions L, W and T and the mass M of the slab shall
be determined. The surface of the slab shall be inspected visually. During this visual inspection, at least
one photo shall be taken of the total area of the slab and any irregularity of the surface shall be
recorded. An alternative way is measuring the 3-dimensional texture of the slab surface by means of
laser texture measurements. Based on these measurements, the volume V of the texture shall be
calculated.
After mounting the slab in the slab fixation box, the slab fixation box shall be mounted in the lateral
moving table, making sure that the surface of the lateral moving table, the slab fixation box and the
surface of the slab are in one plane. In this way, extra vertical forces due to bouncing of the set of
rotating wheels shall be limited.
During the test, the lateral moving table travels 600 times forwards and backwards (so 600 times
forward and 600 times backwards) over the slab. During that time, the wheels are rotating with
(47 ± 1) rpm. After half the number of load repetitions, the slab fixation box shall be rotated 180° and
the bolts in the slab fixation box shall be re-tightened.
The rotation of the slab is necessary to be sure that the surface of the slab is equally loaded over the
whole surface. If, for example, there is some misalignment in the set of rotating wheels or a small
difference in tyre pressure, this influence on the ravelling process is eliminated.
After rotation of the slab halfway through the test, the test can be continued until the end.
Due to the high shear stresses in the contact area between tyre and slab surface, both slab and tyres will
raise in temperature. The maximum allowed temperature of the slab during the test shall be 25 °C and
the temperature of the slab shall never be lower than 18 °C.
NOTE The temperature of the slab and the tyres can be controlled by using an electric fan.
After finishing the test, the slab shall be removed from the slab fixation box. Loose material shall be
removed from the surface of the slab using a vacuum cleaner. The surface shall be inspected visually
and any differences between the initial and end surface shall be reported. One or more pictures of the
surface shall be taken. If available, the three-dimensional texture of the slab surface shall be measured.
Based on these measurements, the volume V of the texture of the slab after testing shall be calculated.
Figure A.1 — Example of the scuffing device
Dimensions in millimetres
Figure A.2 — Example of a longitudinal view of the scuffing device with the lateral moving table
in the left position (the slab fixation box is in the middle of this lateral moving table)
Dimensions in millimetres
Figure A.3 — Example of the set of rotating wheels of the scuffing device
Dimensions in millimetres
Figure A.4 — Example of the slab fixation box of the scuffing device
Annex B
(informative)
The Darmstadt Scuffing Device (DSD)
B.1 Equipment
B.1.1 General
To determine shear stress resistance on asphalt surface courses, a special machine shall be applied. In
the Darmstadt Scuffing Device (DSD) machine, the asphalt specimen shall be attached in a fixture
oscillating 180°, which shall be mounted on a horizontal table moving back and forth. During this
movement, a test tyre under load shall be lowered onto the specimen.
NOTE Two example devices are shown in Figure B.1. The principle of loading system is shown in Figure B.2.
B.1.2 Lateral moving table
The horizontal table shall be guided by a rail through which the table is movable. Powered with an
electric motor linked with the table via scotch yoke, the feed speed shall be held constant at 0,04 m/s
during the test. The rail shall be fixed on a foundation via framework.
On top of the table there shall be a fixture for the specimen that is turning around the axis with an
oscillating amplitude of 180°. Rotational angular velocity shall be kept at 5 turns per minute and can be
applied through the same electric motor that powers the table.
B.1.3 Test tyre
The test tyre shall be a pneumatic tyre without tread (10*4.5-5, slick) mounted onto an axis held by a
fork carriage and freely turnable.
NOTE The fork carriage can be held vertically b
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