EN 12697-31:2007

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Bituminous mixtures - Test methods for hot mix asphalt - Part 31: Specimen preparation by gyratory compactorMélanges bitumineux - Méthodes d'essai pour mélange hydrocarboné a chaud - Partie 31 : Confection d'éprouvettes a la presse a compactage giratoireAsphalt - Prüfverfahren für Heißasphalt - Teil 31: Herstellung von Probekörpern mit dem Gyrator-VerdichterTa slovenski standard je istoveten z:EN 12697-31:2007SIST EN 12697-31:2007en93.080.20Materiali za gradnjo cestRoad construction materialsICS:SIST EN 12697-31:20041DGRPHãþDSLOVENSKI
STANDARDSIST EN 12697-31:200701-junij-2007

EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 12697-31April 2007ICS 93.080.20Supersedes EN 12697-31:2004
English VersionBituminous mixtures - Test methods for hot mix asphalt - Part31: Specimen preparation by gyratory compactorMélanges bitumineux - Méthodes d'essai pour mélangehydrocarboné à chaud - Partie 31 : Confectiond'éprouvettes à la presse à compactage giratoireAsphalt - Prüfverfahren für Heißasphalt - Teil 31:Herstellung von Probekörpern mit dem Gyrator-VerdichterThis European Standard was approved by CEN on 4 February 2007.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the CEN 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 translationunder the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as theofficial versions.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 STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36
B-1050 Brussels© 2007 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 12697-31:2007: E

Contents Page Foreword.4 1 Scope.7 2 Normative references.7 3 Terms, definitions and symbols.8 3.1 Terms and definitions.8 3.2 Symbols.9 4 Principle.10 5 Apparatus.10 5.1 Test device.10 5.2 Metallic moulds.11 5.3 Round metallic inserts.11 5.4 Device for measuring the distance between inserts.11 5.5 Device for counting the number of rotations to within one revolution.11 6 Preparation of specimens.12 6.1 Mass of mixture to be introduced in the mould.12 6.2 Preparation of test pieces.12 7 Test procedure.13 7.1 Preliminary setting.13 7.2 Compaction.13 8 Test report.14 9 Precision.15 Annex A (normative)
Procedure for setting the angle and force for types of gyratory compactor using central reference material.16 A.1 Scope.16 A.2 Principle.16 A.3 Gyratory-type testing procedure.16 A.4 Procedure to test the conformity of a gyratory compactor to a type.18 A.5 Summary of the gyratory calibration chain.19 Annex B (normative)
Procedure to evaluate the gyratory compactor internal angle of gyration using a self-contained measurement unit.20 B.1 Scope.20 B.2 Principle.20 B.3 Equipment.20 B.4 Procedure.21 B.5 Calculation.23 B.6 Compliance.24 B.7 Report.25 B.8 Precision data.25 Annex C (normative)
Procedure to evaluate the gyratory compactor (GC) internal angle of gyration and related parameters using simulated loading.26 C.1 Scope.26 C.2 Principle.26 C.3 Procedure.26 C.4 Calculation of results.27 C.5 Compliance.28

gyratory compactor type representative model of a given production compactor 3.1.2
force-angle calibration chain force F and the angle φ determined for a type of gyratory compactor in order to comply with the central reference material requirements in Table A.1 NOTE Production gyratory compactors of the same type are adjusted using the determined values of F and φ. The conformity of a production gyratory compactor to a type can be verified by doing a comparative test on a bituminous mixture or by checking the variations of the internal angle as described in A.3.3. 3.1.3
central reference material two bituminous mixtures, produced under defined conditions from constituents stored at a given site, of which the compositions are not specified but the air voids content (the constancy of which is traceable) at fixed numbers of gyrations complies respectively NOTE The characteristics of the central reference material are specified in Table A.1. 3.1.4
internal angle angle between the internal mould cross-sectional plane and the metallic insert as a mould is gyrated in a gyratory compactor 3.1.5
internal top angle angle between the internal mould cross-sectional plane and the upper metallic insert as a mould is gyrated in a gyratory compactor 3.1.6
internal bottom angle angle between the internal mould cross-sectional plane and the lower metallic insert as a mould is gyrated in a gyratory compactor 3.1.7
internal effective angle average of the internal top angle and the internal bottom angle 3.1.8
eccentricity distance, e, away from the axis of gyration at which a force, F, is acting at one end of a gyratory compactor mould NOTE The eccentricity is explained in Figure C.1.

tilting moment product of the eccentricity, e, and the force, F, acting at one end of a gyratory compactor mould in a direction parallel to the axis of gyration NOTE The tilting moment is explained in Figure C.1. 3.2 Symbols For the purposes of this document, the following symbols apply. α is the internal angle, in degrees (°); φ
is the angle of incline of axis of test piece, in degrees (°); F is the axial resultant force applicable to the ends of the test pieces, in newton (N); ω is the speed of rotation of the axis of symmetry of revolution of the test piece, in revolutions per minute (rev/min); D is the internal diameter of the mould, in millimetres (mm); M is the mass of the mixture to be introduced in the mould, in kilograms (kg); ρM is the maximum density of the mixture, in kilograms per cubic metre (kg/m3); hmin is the minimum height of compacted specimen, corresponding to a zero percentage of voids, in millimetres (mm); h(ng) is the height of specimen after a number of gyrations ng, in millimetres (mm); ρ(ng) is the bulk density of specimen after a number of gyrations ng, in kilograms per cubic metre (kg/m3); P is the preload, initial value of F, in newton (N); v % is the void content, in percent (%); e is the eccentricity, in millimetres (mm); ITa1…4
is the measured internal top angle (4 individual measurements); ITamin is the minimum measured internal top angle (of 4 measurements); ITamax is the maximum measured internal top angle (of 4 measurements); ITA
is the internal top angle (average of 4 measurements) ITA240
is the internal top angle at 240 Nm tilting moment; IBa1…4 is the measured internal bottom angle (4 individual measurements); IBamin is the minimum measured internal bottom angle (of 4 measurements); IBamax is the maximum measured internal bottom angle (of 4 measurements); IBA
is the internal bottom angle (average of 4 measurements) IBA240
is the internal bottom angle at 240 Nm tilting moment;

is the internal effective angle (average of ITA and IBA); IEA240
is the internal effective angle at 240 Nm tilting moment; IEA425
is the internal effective angle at 425 Nm tilting moment; /TB(240)
is the difference between ITA and IBA at 240 Nm; /TB(425)
is the difference between ITA and IBA at 425 Nm; /LH
is the difference between IEA240 and IEA425. 4 Principle The bituminous mixture is contained within a cylindrical mould limited by inserts and kept at a constant temperature within specified tolerances throughout the whole duration of the test. Compaction is achieved by the simultaneous action of a low static compression, and of the shearing action resulting from the motion of the axis of the mould which generates a conical surface of revolution, of apex O and of 2 φ angle at the apex, while the ends of the test piece should ideally remain perpendicular to the axis of the conical surface (see Figure 1).
Key F axial resultant force h (ng) height of specimen after a number of gyrations φ angle Figure 1 — Test piece motion diagram NOTE When the specimen is taken out of the equipment for use in other mechanical tests, the temperature and pressure will change and can affect the measured density. The density should then be measured in accordance with the relevant part of EN 12697-6. 5 Apparatus 5.1 Test device Test device:
capable of compacting the test specimen according to the principle described in Clause 4 and in accordance with the requirements of Clause 7, concerning the angle and the force;

capable of maintaining at least one point in the vicinity of the mid-plane, located between 30 mm and 45 mm from the mould axis, at within ±10 °C of the prescribed temperature during the test;
capable of maintaining the speed of rotation constant during the test to ± 10 % at speeds up to 32 rev/min. The angle and the force shall conform to the provisions of Annex A, Annex B or Annex C. NOTE Annex A is especially suitable for void content evaluation and compaction research and Annex B and Annex C for the preparation of specimens for mechanical testing. 5.2 Metallic moulds Metallic moulds:  having a surface hardness greater than 48 HRC according to EN ISO 6508-1;  having either: - a roughness Ra less than 1 µm according to EN ISO 4287 or - an initial roughness under 0,8 µm according to EN ISO 4287 and no defects, scratches or traces visible to the naked eye;  having in the zone in contact with the material during the compaction, an internal diameter of (150,0 ± 0,1) mm or (160,0 ± 0,1) mm or (100,0 ± 0,1) mm;  having a height compatible with the volume of material of the specimens under test;  having a thickness greater than 7,5 mm. 5.3 Round metallic inserts Round metallic inserts:
having an even active surface to within ± 0,1 mm (that surface intended to be in contact with the material);
having a surface hardness not less than 55 HRC according to EN ISO 6508-1;
having either a roughness Ra under 0,8 µm according to EN ISO 4287 or an initial roughness under 0,8 µm according to EN ISO 4287 and subject to no defects, scratches or traces visible to the naked eye;
having a shape appropriate to the kinetics of the motion and a diameter resulting in an insert/mould play between 0,1 mm and 0,6 mm. 5.4 Device for measuring the distance between inserts 5.5 Device for counting the number of rotations to within one revolution

Mmin29410ρπhDM−= (1) where M is the mass of the mixture to be introduced in the mould, in kilograms (kg); D is the internal diameter of the mould, in millimetres (mm); hmin is the minimum height of compacted specimen, corresponding to a zero percentage of voids, in millimetres (mm); ρM is the maximum density of the mixture, in kilograms per cubic metre (kg/m3). For a given type of gyratory compactor calibrated using Annex A, hmin will be constant. The ratio of hmin to the internal diameter of the mould D shall be in the interval 0,66 to 1,05. 6.2 Preparation of test pieces If the bituminous mixture is prepared in the laboratory, it shall be prepared in accordance with EN 12697-35. If it is cut or cored in a compacted layer, the size of the sample shall be such that the mass M prescribed in 6.1.2 can be taken from it. If the nominal maximum size of the aggregates is 16 mm or less, the diameter of the specimens shall be 100 mm, 150 mm or 160 mm. If the maximum size of the aggregates is more than 16 mm, the diameter of the specimens shall be 150 mm or 160 mm. The following operations shall be carried out:
place moulds and inserts for at least 2 h within an enclosure brought to the test temperature ± 10 °C;
lubricate moulds with a coating of glycerised soda oleate applied with a brush, or of silicon grease;
if the sample has been cut or cored in a compacted layer, bring it to a temperature at which the bituminous mixture is loose enough, so that the prescribed mass M can be taken;
weigh the mould and inserts, fill the mould with the mixture by means of a funnel and weigh the mould and inserts plus the mixture in the mould, so that the prescribed mass M of bituminous mixture in the mould is obtained with an accuracy of 0,1 %;
alternatively, weigh the mass M of the bituminous mixture in an intermediate container, to an accuracy of 0,1 %, and introduce the bituminous mixture into the mould by means of a funnel in one operation only.

± 10 °C for between 30 min and 2 h. However, for SMA there is a risk for segregation. 7 Test procedure 7.1 Preliminary setting 7.1.1 Pre-load In case of a pre-load P, it shall be between 150 N and 3 000 N inclusive. 7.1.2 Force F Force F is defined in A.3.2 for void content requirement test and in B.4.1 or in C.1, for specimens for further mechanical tests. 7.1.3 Setting of the angle of inclination The angle
shall conform to the provisions of Annex A, Annex B or Annex C. NOTE Annex A is especially suitable for compaction research and Annex B and Annex C for the preparation of specimens for mechanical testing. If both activities are to be covered, then it is advised to use Annex B or Annex C. However, it should be emphasized that gyratory compactors that are calibrated with Annex A are also suitable to prepare specimens for mechanical testing although this option is not recommended. For Annex A, the setting of the angle φ of the type is verified on the basis of a test conducted on central reference materials with the representative model according to the provisions of A.1. The minimal conditions for compliance of a gyratory compactor model with a standard model are defined in A.2. The setting of the angle of inclination α or φ is that which is determined for the gyratory compactor in accordance with A.2 to within ± 0,02°. 7.1.4 Speed of rotation The speed of rotation shall be maintained constant during the test to ± 10 %. 7.1.5 Temperature The compaction temperatures shall be as given in EN 12697-35. 7.2 Compaction 7.2.1 Start of compaction Place the mould containing the mixture and the inserts in the test device. In the case of a pre-load, it shall be applied during an interval of less than 30 s. With the mechanical head in contact with the upper insert, start the rotation of the machine. The load F and the angle of incline φ shall be applied within the first gyration. In other cases, apply the load F and the angle of incline φ and start the rotation of the machine. 7.2.2 Specimens for void content requirement Without interrupting rotation, measure the height of the specimen h(ng), to ± 0,2 mm for the following numbers of gyrations: 5, 10, 15, 20, 25, 30, 40, 50, 60, 80, 100, and if necessary 120, 150, 200, 300, 400, 500 gyrations.

()−=)()(100%gmingnhhnhnvg (2) where v(ng) is the void content after a number of gyrations ng, in percentage (%); h(ng) is the height of the specimen after a number of gyrations ng, in millimetres (mm); hmin is the minimum height of the compacted specimen, corresponding to a zero percentage of voids, in millimetres (mm). Unless otherwise stated, if the result of the test is to be interpreted as a single result, a test result on a given mixture shall be the mean value of at least three elementary determinations. If the coefficient of variation of the heights of the specimens is higher than 1,5 %, for a number of gyrations more than 20, the test shall be rejected. 7.2.3 Specimens for further testing When the required height of the specimen is obtained stop the rotation of the machine. If further tests are required, the ends of the specimen shall be adjusted such that they are perpendicular to its axis using one of the three methods following:
apply two to ten additional revolutions, while the angle φ
is progressively or step by step set to zero;
remove the mould from the gyratory compactor; apply a static load of (8 000 ± 500) N for 100 mm diameter specimens or (20 000 ± 1 000) N for 150 mm or 160 mm diameter specimens, parallel to the axis of the mould, on
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