SIST-TS CEN/TS 15324:2008

SLOVENSKI STANDARD
SIST-TS CEN/TS 15324:2008
01-julij-2008
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Bitumen and bituminous binders - Determination of equiviscous temperature based on
Low Shear Viscosity using a Dynamic Shear Rheometer in low frequency oscillation
mode
Bitumen und bitumenhaltige Bindemittel - Bestimmung der Äquiviskositätstemperatur
basierend auf niedriger Scherviskosität mit Hilfe eines dynamischen Scher-Rheometers
in niederfrequentem Schwingungsmodus
Bitumes et liants bitumineux - Détermination de la température d'équiviscosité basée sur
la mesure de la viscosité a faible taux de cisaillement utilisant un rhéometre a
cisaillement dynamique (DSR) en mode oscillatoire a basse fréquence
Ta slovenski standard je istoveten z: CEN/TS 15324:2008
ICS:
75.140 Voski, bitumni in drugi naftni Waxes, bituminous materials
proizvodi and other petroleum products
91.100.50 Veziva. Tesnilni materiali Binders. Sealing materials
SIST-TS CEN/TS 15324:2008 en,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST-TS CEN/TS 15324:2008

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SIST-TS CEN/TS 15324:2008
TECHNICAL SPECIFICATION
CEN/TS 15324
SPÉCIFICATION TECHNIQUE
TECHNISCHE SPEZIFIKATION
April 2008
ICS 91.100.50

English Version
Bitumen and bituminous binders - Determination of equiviscous
temperature based on Low Shear Viscosity using a Dynamic
Shear Rheometer in low frequency oscillation mode
Bitumes et liants bitumineux - Détermination de la Bitumen und bitumenhaltige Bindemittel - Bestimmung der
température d'équiviscosité basée sur la mesure de la Äquiviskositätstemperatur basierend auf Viskosität bei
viscosité à faible taux de cisaillement utilisant un rhéomètre niedriger Schergeschwindigkeit mit Hilfe eines
à cisaillement dynamique (DSR) en mode oscillatoire à dynamischen Scher-Rheometers in niederfrequentem
basse fréquence Schwingungsmodus
This Technical Specification (CEN/TS) was approved by CEN on 23 March 2007 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, Cyprus, Czech Republic, Denmark, Estonia, Finland,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2008 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TS 15324:2008: E
worldwide for CEN national Members.

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SIST-TS CEN/TS 15324:2008
CEN/TS 15324:2008 (E)
Contents Page
Foreword.3
1 Scope .4
2 Normative references .4
3 Terms and definitions .4
4 Principle.7
5 Apparatus .7
6 Preparation of rheometer and specimen.8
7 Procedure .9
8 Expression of results .11
9 Precision.12
10 Test reports .13
Annex A (informative) Test examples .14
Annex B (informative) Temperature verification procedure .23
Bibliography .24

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Foreword
This document (CEN/TS 15324:2008) has been prepared by Technical Committee CEN/TC 336 “Bituminous
binders”, the secretariat of which is held by AFNOR.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
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, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.
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SIST-TS CEN/TS 15324:2008
CEN/TS 15324:2008 (E)
1 Scope
This document describes the determination of the EquiViscous Temperature (EVT) of bitumen or bituminous
binder samples, based on a defined, practice related Low Shear Viscosity (LSV), using a Dynamic Shear
Rheometer (DSR) in low frequency oscillation mode.
The EquiViscous Temperature (EVT) measured by this binder test is seen as a performance indicator for the
partial contribution of the bituminous binder to the rutting resistance of the compacted asphalt mixture under
service conditions at elevated pavement temperatures.
The test method described in this document is applicable to unaged, aged and recovered bituminous binders
including Polymer Modified Binders (PMBs).
WARNING — Use of this document can involve hazardous materials, operations and equipment. This
document does not purport to address all of the safety problems associated with its use. It is the
responsibility of the user of this document to establish appropriate safety and health practices and
determine the applicability of regulatory limitations prior to use. Since this document involves
handling apparatus and binders at high temperatures, always wear protective gloves and eye glasses
when handling hot binder, and avoid contact with any exposed skin.
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 12594, Bitumen and bituminous binders – Preparation of test samples
ISO 5725-2, Accuracy (trueness and precision) of measurement methods and results – Part 2: Basic method
for the determination of repeatability and reproducibility of a standard measurement method
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
complex shear modulus G*
*
τ
* * iδ * * 2
G = = G e = G cosδ +iG sinδ =G'+iG"  (i=-1) (1)
*
γ
where
 G* is the complex shear modulus, expressed in Pascal (Pa);
*
 τ is the harmonic, sinusoidal shear stress, expressed in Pascal (Pa);
*
 γ is the harmonic, sinusoidal shear strain;
*
 G is the norm of the complex shear modulus, ratio of peak stress to peak strain in harmonic,
sinusoidal oscillation;
 δ is the phase angle of the complex shear modulus, shift between stress and strain in harmonic,
sinusoidal oscillation;
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 G’ is the real part of the complex shear modulus (storage modulus);
 G” is the imaginary part of the complex shear modulus (loss modulus)
3.2
complex viscosity ηηηη*
* *
τ G G" G'
*
η = = = −i = η'−iη" (2)
*
γ& iω ω ω
where
 η* is the complex viscosity, expressed in Pascal. second (Pa.s);
*
 τ is the harmonic, sinusoidal shear stress, expressed in Pascal (Pa);
* -1
&
 γ is the harmonic, sinusoidal shear strain rate, expressed in second (1/s);
 η’ is the real part of the complex viscosity (dynamic viscosity);
 η” is the imaginary part of the complex viscosity;
 ω is the angular frequency, expressed in radian/second (rad/s).
*
G
*
η =
η =
&
γ
ω
           (3)
where
η : viscosity (calculated from complex modulus, measured at low shear rate) in Pa.s;
&
γ
*
─ η : norm of complex viscosity, ratio of peak shear stress to peak shear rate in harmonic sinusoidal
oscillation, in (Pa ⋅ s);
ω (rad / s) = 6,28318 f (Hz) (4)
where
─ f : frequency of sinusoidal oscillation, in Hz.
3.3
Zero Shear Viscosity (ZSV), ηηηη
0
dynamic viscosity of bitumen depends on the shear stress or shear strain rate level (i.e. non-Newtonian
substance)
The shear thinning or pseudo-plastic behaviour is characterised by decreasing viscosity with increasing shear

stress or shear rate between two well defined values: ”Zero Shear Viscosity” η at zero and “Limiting
0
Viscosity” η at infinitely high shear stress or shear rate (Figure 1).
∞

The dynamic viscosity in the intermediate domain between η and η is called “Apparent Viscosity” because
0 ∞
it depends on the (incident) loading conditions
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Key
A Zero shear viscosity η (ZSV)
&
X log shear stress τ , or log shear rate γ o
B Low shear viscosity η (LSV)
&
γ
1
Y log dynamic viscosity η
C apparent viscosity η
D limiting viscosity η
oo
Figure 1 — Definition of the Zero Shear Viscosity (ZSV), Low Shear Viscosity (LSV)
and increase in viscosity ηηηη with decreasing shear stress or shear rate
∆∆∆∆
3.4
Low Shear Viscosity (LSV) η
γ&
dynamic viscosity at low shear stress or shear rate, where “low” means close to zero (see Figure 1). The
concept of LSV is introduced because it can be measured directly: it is derived from the complex modulus
measured with DSR in oscillation mode at low frequencies in combination with low strain amplitudes (see
Equation (3)). As seen in Figure 1, LSV is smaller than ZSV:
η = η + ∆η (5)
0 γ&
The lower the shear stress or shear rate at which LSV is measured, the closer the value will approximate the
ZSV
3.5
EquiViscous Temperature (EVT) related to Low Shear Viscosity (LSV)
temperature at which a bitumen sample exhibits a given LSV (e.g. 2 kPa⋅s), at a given shear stress or shear
rate
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4 Principle
4.1 General
The EquiViscous Temperature, based on a defined Low Shear Viscosity, indicates the rutting susceptibility of
the binder. EVT can only be used for comparing or ranking binders when the EVT is based on the same LSV,
measured at the same shear stress or shear rate.
The test is performed in two steps.
4.2 Test part 1: temperature sweep
A temperature sweep is carried out to determine the equiviscous temperature value EVT1 related to a defined
Low Shear Viscosity η (e.g. 2 kPa.s) at a low frequency (e.g. 0,01 Hz) and a low strain amplitude (e.g. 0,1).
γ&
1
The procedure is described in sub-clause 7.1.
4.3 Test part 2: frequency sweep
A frequency sweep at test temperature EVT1 (determined in test part 1) is carried out from a higher frequency
(e.g. 1 Hz) to a lower frequency (e.g. 0,0 003 Hz) with an additional extrapolation to e.g. 0,0001 Hz. This will
reveal a higher value of LSV (and likewise a higher value ETV2 than ETV1), which is a closer approximation
to ZSV.

The difference ∆T between EVT2 and EVT1 shall be calculated from the increase of LSV, as explained in sub-

clause 7.2.
∆T (°C) = EVT2 (°C) - EVT1 (°C) (6)
For routine testing purposes, e.g. quality control, a significant simplification of the test procedure is possible by
measuring only EVT1 by a temperature sweep at a low frequency in the magnitude of f = 0,01 Hz.
Particularly for PMBs, test part 2 can reveal a significant increase in EVT. Therefore, EVT2 shall be measured
by carrying out a frequency sweep to lower frequency.
All measurements shall be carried out in the linear viscoelastic region (see Clause 7).
NOTE It is recommended to systematically apply the same values of LSV, shear strain and frequency, as
recommended by the notes in Clause 7 of this standard. Only then will it be possible to use the EVT for ranking binders.
5 Apparatus
Usual laboratory apparatus and glassware, together with the following:
5.1 Dynamic shear rheometer (DSR), with either an integral temperature control system or temperature
control attachments, capable of controlling the temperature over a minimum range of 5 °C to 85 °C with an
accuracy of ± 0,1 °C throughout the test period. The rheometer shall be fitted with parallel plates, with a
constant gap across the area of the plates. The temperature control system shall encompass both plates to
avoid temperature gradients across the plates. When the test specimen is immersed in liquid other than water,
ensure that the liquid does not affect the properties of the material being analysed. The rheometer shall be
able to determine G * in the range of 10 Pa to 10 MPa (± 2 %).
For rheometers using an air bearing, and to avoid damage, the air supply to the bearing shall be switched on
before the instrument is switched on. When not in use, the spindle shall be secured.
Make a visual check to ensure the two plates are vertically aligned. If there is any doubt as to the alignment,
the manufacturer or a qualified technician shall re-align the plate geometry.
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The rheometer and temperature control system shall be calibrated at regular time intervals.
NOTE 1 When liquid is used to immerse the test specimen, a water/glycol mixture has been found to be suitable.
NOTE 2 For bituminous binders it is recommended to use a plate diameter of 25 mm and a gap of 1 mm. Plates of
different diameters and gaps between 0,5 and 2 mm can also be used, provided compliance effects of the instrument do
not affect the results and the testing is done within the specified range of torque and angular deformation and within the
linear region (see sub-clause 7.1, NOTE 5). This should be valid at any applied temperature and frequency.
NOTE 3 It is recommended that the rheometer and temperature control system are calibrated by a means traceable to
a National Standard. Also, it is advisable to verify the accuracy of the temperature control system by means of a certified
temperature measuring device at regular intervals, such as a type P thermocouple. Also note that external devices read
the accurate temperature value only if they are calibrated correctly.
5.2 Moulds or vials, for preparing the test specimens. The moulds where used, shall be of silicone or similar
material that does not adhere to the test specimen. Vials, where used, shall be of glass with a nominal
capacity of 10 ml.
5.3 Oven, ventilated laboratory model, capable of being controlled at temperatures between 50 °C and
200 °C with an accuracy of ± 5 °C.
6 Preparation of rheometer and specimen
6.1 Rheometer set-up
Set up the rheometer in the sequence given in the manufacturer's instructions, including the procedure for
selecting and setting the parallel plate geometry and gap. It is essential that the operational limits of stiffness
for the selected geometry are determined (see also sub-clause 5.1, NOTE 2).
Select the appropriate oscillation package, if applicable, from the software menu.
Carefully prepare the rheometer plates by cleaning with a suitable solvent and soft cleaning cloth or paper. Do
not use metal or any other materials, which may damage the surfaces of the plates, and take care not to bend
the shaft of the upper plate.
6.2 Gap setting
Apply the manufacturer’s procedure to set the gap between the plates prior to loading the test specimen, with
both plates at nominally the same temperature.
The effective gap will be affected by the actual temperature in the geometry. If the DSR has no automatic gap
compensation feature, the method of correcting gap changes for temperatures different from the gap setting
temperature shall be reported.
NOTE 1 According to sub-clause 5.1, NOTE 2, a gap of 1 mm is recommended.
NOTE 2 If the DSR has an automatic gap compensation feature, the gap may be set at any temperature within the
range covered. If the DSR has no gap compensation feature, it is recommended that the gap is set at a number of
different mid-point temperatures not exceeding 15 °C intervals within the range tested.
6.3 Specimen preparation
Prepare the binder sample in accordance with EN 12594.
Two methods can be used for preparing the test specimens:
 specimen preparation in a mould (preferred method);
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 directly pouring onto the test plate.
In the latter case, pour sufficient binder from the vial onto the test geometry for there to be an excess
appropriate to the measuring geometry chosen. Discard any binder remaining in the vial. If preferred, weigh
the required quantity of binder directly on to the approximate centre of the measuring geometry being used.
Proceed to sub-clause 6.4.
If using moulds, pour sufficient binder into the mould. To avoid successive sample heating, several specimens
may be prepared at this stage. Discard any binder remaining in the vial.
Store the covered moulds or sheet material at ambient temperature before testing. Any specimen not tested
within 7 days shall be discarded.
To minimise the effect of sample preparation, it is advised to pour the specimens 24 h before measuring.
Before testing, if necessary, place the specimens in a refrigerator (approximately 5 °C) to allow them to stiffen
for proper, deformation-free release from the moulds. To avoid physical hardening, it is recommended not to
leave the specimens in the cool chamber for any longer than the time needed to obtain proper stiffness. The
recommended time is approximately 10 min and shall not exceed 30 min.
Release the specimens from
...