# SIST EN 12697-24:2012

(Main)## Bituminous mixtures - Test methods for hot mix asphalt - Part 24: Resistance to fatigue

## Bituminous mixtures - Test methods for hot mix asphalt - Part 24: Resistance to fatigue

This European Standard specifies the methods for characterising the fatigue of bituminous mixtures by alternative tests, including bending tests and direct and indirect tensile tests. The tests are performed on compacted bituminous material under a sinusoidal loading or other controlled loading, using different types of specimens and supports.

The procedure is used to rank bituminous mixtures on the basis of resistance to fatigue, as a guide to relative performance in the pavement, to obtain data for estimating the structural behaviour in the road and to judge test data according to specifications for bituminous mixtures.

Because this European Standard does not impose a particular type of testing device, the precise choice of the test conditions depends on the possibilities and the working range of the used device. For the choice of specific test conditions, the requirements of the product standards for bituminous mixtures need to be respected. The applicability of this document is described in the product standards for bituminous mixtures.

Results obtained from different test methods or using different failure criteria are not assured to be comparable.

## Asphalt - Prüfverfahren für Heißasphalt - Teil 24: Beständigkeit gegen Ermüdung

Diese Europäische Norm legt die Verfahren fest zur Charakterisierung der Ermüdung von Asphalt durch verschiedene Prüfungen, einschließlich Biegeprüfungen und Prüfungen der direkten sowie der indirekten Zug-festigkeit. Die Prüfungen werden an verdichtetem Asphalt unter sinusförmiger oder einer anderen kontrollier-ten Belastung unter Verwendung verschiedener Probekörpertypen und Auflagerungen vorgenommen. Das Verfahren dient zur Einstufung von Asphalt nach seiner Beständigkeit gegen Ermüdung, als Hinweis auf sein relatives Leistungsvermögen in der Fahrbahnbefestigung, um Daten zur Abschätzung des Tragverhal-tens in der Straße zu erhalten und die Prüfdaten nach den für Asphalt geltenden Festlegungen zu beurteilen. Da diese Europäische Norm keinen bestimmten Prüfgerätetyp vorschreibt, hängt die genaue Auswahl der Prüfbedingungen von den Möglichkeiten und dem Arbeitsbereich des im betreffenden Fall verwendeten Prüf-geräts ab. Bei der Auswahl der jeweiligen Prüfbedingungen müssen die Anforderungen der Produktnormen für Asphalt berücksichtigt werden. Die Anwendbarkeit dieses Dokumentes ist in den Produktnormen für Asphalt beschrieben. Die mit verschiedenen Prüfverfahren oder unter Anwendung verschiedener Ausfallkriterien erhaltenen Prüfergebnisse sind nicht notwendigerweise miteinander vergleichbar.

## Mélanges bitumineux - Méthodes d'essai pour mélange hydrocarboné à chaud - Partie 24: Résistance à la fatigue

La présente Norme européenne spécifie les méthodes qui sont utilisées pour caractériser la fatigue des

mélanges bitumineux par différents types d'essais, dont des essais de flexion et des essais de traction directe

et indirecte. Les essais sont réalisés sur des matériaux bitumineux compactés, au moyen d'une charge

sinusoïdale ou d'une autre charge contrôlée, en utilisant différents types d'éprouvettes et de supports.

La procédure est utilisée :

a) pour classer les mélanges bitumineux selon leur résistance à la fatigue ;

b) comme guide comparatif des performances dans les structures de chaussée ;

c) pour obtenir des données permettant d'estimer le comportement structurel du matériau de la chaussée ;

et

d) pouvoir juger les résultats d'essais en fonction des spécifications des mélanges bitumineux.

Comme la présente Norme européenne n'impose pas un type de dispositif d'essai particulier, le choix précis

des conditions d'essai dépend des possibilités et de la plage de fonctionnement du dispositif utilisé. Pour le

choix des conditions d'essai spécifiques, il est nécessaire de respecter les critères des normes produit des

mélanges bitumineux. L’applicabilité du présent document est décrite dans les normes produit des mélanges

bitumineux.

Il n'est pas certain que les résultats obtenus selon les différentes méthodes d'essai ou en utilisant les

différents critères de rupture soient comparables.

## Bitumenske zmesi - Preskusne metode za vroče asfaltne zmesi - 24. del: Odpornost proti utrujanju

Ta evropski standard določa metode za karakterizacijo utrujenosti bitumenskih zmesi z alternativnimi preskusi, skupaj s preskusi upogiba ter preskusi direktne in indirektne nateznosti. Preskusi se izvajajo na zgoščenem bitumenskem materialu pod sinusnim obremenjevanjem ali pod nadzorovanim obremenjevanjem z različnimi vrstami preskušancev in podpor. Postopek se uporablja za razvrščanje bitumenskih zmesi na podlagi odpornosti proti utrujanju kot smernica v zvezi z relativnimi lastnostmi v voziščni konstrukciji za pridobivanje podatkov z namenom vrednotenja strukturnega obnašanja na cesti ter za ocenjevanje preskusnih podatkov glede na specifikacije bitumenskih zmesi. Ker ta evropski standard ne predpisuje posebne preskusne naprave, je natančna izbira preskusnih pogojev odvisna od možnosti in delovnega obsega uporabljene naprave. Pri izbiri specifičnih preskusnih pogojev je treba upoštevati standarde za izdelke za bitumenske zmesi. Uporabnost tega dokumenta je opisana v standardih za izdelke za bitumenske zmesi. Rezultati, pridobljeni z različnimi preskusnimi metodami ali z uporabo različnih meril odpovedi, niso nujno primerljivi.

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2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Asphalt - Prüfverfahren für Heißasphalt - Teil 24: Beständigkeit gegen ErmüdungMélanges bitumineux - Méthodes d'essai pour mélange hydrocarboné à chaud - Partie 24: Résistance à la fatigueBituminous mixtures - Test methods for hot mix asphalt - Part 24: Resistance to fatigue93.080.20Materiali za gradnjo cestRoad construction materialsICS:Ta slovenski standard je istoveten z:EN 12697-24:2012SIST EN 12697-24:2012en,fr,de01-september-2012SIST EN 12697-24:2012SLOVENSKI

STANDARDSIST EN 12697-24:2004+A1:20071DGRPHãþD

SIST EN 12697-24:2012

EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM

EN 12697-24

May 2012 ICS 93.080.20 Supersedes EN 12697-24:2004+A1:2007English Version

Bituminous mixtures - Test methods for hot mix asphalt - Part 24: Resistance to fatigue

Mélanges bitumineux - Méthodes d'essai pour mélange hydrocarboné à chaud - Partie 24: Résistance à la fatigue Asphalt - Prüfverfahren für Heißasphalt - Teil 24: Beständigkeit gegen Ermüdung This European Standard was approved by CEN on 23 March 2012.

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, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom.

EUROPEAN COMMITTEE FOR STANDARDIZATION

COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre:

Avenue Marnix 17,

B-1000 Brussels © 2012 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 12697-24:2012: ESIST EN 12697-24:2012

EN 12697-24:2012 (E) 2 Contents PageForeword .41Scope .82Normative references .83Terms, definitions, symbols and abbreviations .83.1General .93.2Two-point bending test on trapezoidal specimens .93.3Two-point bending test on prismatic shaped specimens . 103.4Three-point bending test on prismatic shaped specimens . 123.5Four-point bending test on prismatic shaped specimens . 133.6Symbols for indirect tensile test on cylindrical shaped specimens . 184Sample preparation . 194.1Age of the specimens . 194.2Drying of the specimen . 194.3Dimensions and bulk density of the specimens . 195Failure . 196Calculations . 197Summary of the procedures . 197.1Two-point bending test on trapezoidal specimens . 197.2Two-point bending test on prismatic shaped specimens . 197.3Three-point bending test on prismatic shaped specimens . 207.4Four-point bending test on prismatic shaped specimens . 207.5Indirect tensile test on cylindrical shaped specimens . 208Checking of the testing equipment . 209Test report . 21Annex A (normative)

Two-point bending test on trapezoidal shaped specimens . 22A.1Principle . 22A.2Equipment . 23A.3Specimen preparation . 23A.4Procedure . 26A.5Calculation and expression of results . 27A.6Test report . 28A.7Precision . 28Annex B (normative)

Two-point bending test on prismatic shaped specimens . 30B.1Principle . 30B.2Equipment . 30B.3Specimen preparation . 31B.4Procedure . 31B.5Calculation and expression of results . 32B.6Test report . 34B.7Precision . 34Annex C (normative)

Three-point bending test on prismatic shaped specimens . 35C.1Principle . 35C.2Equipment . 35C.3Specimen preparation . 36C.4Procedure . 36SIST EN 12697-24:2012

EN 12697-24:2012 (E) 3 PageC.5Calculation and expression of results.37C.6Test report . 40C.7Precision. 41Annex D (normative)

Four-point bending test on prismatic shaped specimens . 42D.1Principle. 42D.2Equipment . 44D.3Specimen preparation . 45D.4Procedure . 46D.5Calculation and expression of results . 48D.6Test report . 48D.7Precision. 48Annex E (normative)

Indirect tensile test on cylindrical shaped specimens . 49E.1Principle. 49E.2Equipment . 49E.3Specimen preparation . 52E.4Procedure . 53E.5Calculation and reporting of results . 53E.6Test report . 56E.7Precision. 56Bibliography . 57

SIST EN 12697-24:2012

EN 12697-24:2012 (E) 4 Foreword This document (EN 12697-24:2012) has been prepared by Technical Committee CEN/TC 227 “Road materials”, the secretariat of which is held by DIN. 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 November 2012, and conflicting national standards shall be withdrawn at the latest by November 2012. 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. This document supersedes EN 12697-24:2004+A1:2007. The main changes with respect to the previous edition are as follows: clarification in the scope that tests using different failure criteria are not comparable; definition of conventional criteria of fatigue for constant force deleted, leaving just constant displacement; definitions of the average and standard deviation of the fatigue life of a series of specimens for the two-point and four-point bending tests on prismatic specimens removed; symbols for the frequency of the sinusoidal load applications and angular speed revised; requirements on age and drying of specimens added in the main text and removed from the individual annexes; limits on interpolation defined; alternative criterion given in a note; requirement for checking (rather than calibration of) the test equipment added in the main text and removed from the individual annexes; requirement added for the test report to include information on the chosen test method, the used testing equipment, results of the last check on calibration of the testing equipment and the age of the specimen at the time of testing; the tolerance for the displacement of the trapezoidal specimen widened; measurements on the three-point bending test on prismatic specimens started after fewer cycles; note added on rotating the specimen in four-point bending test on prismatic specimens; the optional requirement for choosing frequency spectrum of initial complex (stiffness) moduli removed from the four-point bending test on prismatic specimens; the principle, equipment, procedure and calculations of the indirect tensile test on cylindrical specimens revised. This document is one of a series of standards for bituminous mixtures which includes the following: SIST EN 12697-24:2012

EN 12697-24:2012 (E) 5 EN 12697-1, Bituminous mixtures — Test methods for hot mix asphalt — Part 1: Soluble binder content EN 12697-2, Bituminous mixtures — Test methods for hot mix asphalt — Part 2: Determination of particle size distribution EN 12697-3, Bituminous mixtures — Test methods for hot mix asphalt — Part 3: Binder recovery: Rotary evaporator EN 12697-4, Bituminous mixtures — Test methods for hot mix asphalt — Part 4: Binder recovery: Fractionating column EN 12697-5, Bituminous mixtures — Test methods for hot mix asphalt — Part 5: Determination of the maximum density EN 12697-6, Bituminous mixtures — Test methods for hot mix asphalt — Part 6: Determination of bulk density of bituminous specimens EN 12697-7, Bituminous mixtures — Test methods for hot mix asphalt — Part 7: Determination of bulk density of bituminous specimens by gamma rays EN 12697-8, Bituminous mixtures — Test methods for hot mix asphalt — Part 8: Determination of void characteristics of bituminous specimens EN 12697-10, Bituminous mixtures — Test methods for hot mix asphalt — Part 10: Compactibility EN 12697-11, Bituminous mixtures — Test methods for hot mix asphalt — Part 11: Determination of the affinity between aggregate and bitumen EN 12697-12, Bituminous mixtures — Test methods for hot mix asphalt — Part 12: Determination of the water sensitivity of bituminous specimens EN 12697-13, Bituminous mixtures — Test methods for hot mix asphalt — Part 13: Temperature measurement EN 12697-14, Bituminous mixtures — Test methods for hot mix asphalt — Part 14: Water content EN 12697-15, Bituminous mixtures — Test methods for hot mix asphalt — Part 15: Determination of the segregation sensitivity EN 12697-16, Bituminous mixtures — Test methods for hot mix asphalt — Part 16: Abrasion by studded tyres EN 12697-17, Bituminous mixtures — Test methods for hot mix asphalt — Part 17: Partial loss of porous asphalt specimen EN 12697-18, Bituminous mixtures — Test methods for hot mix asphalt — Part 18: Binder drainage EN 12697-19, Bituminous mixtures — Test methods for hot mix asphalt — Part 19: Permeability of specimen EN 12697-20, Bituminous mixtures — Test methods for hot mix asphalt — Part 20: Indentation using cube or Marshall specimens EN 12697-21, Bituminous mixtures — Test methods for hot mix asphalt — Part 21: Indentation using plate specimens EN 12697-22, Bituminous mixtures — Test methods for hot mix asphalt — Part 22: Wheel tracking EN 12697-23, Bituminous mixtures — Test methods for hot mix asphalt — Part 23: Determination of the indirect tensile strength of bituminous specimens SIST EN 12697-24:2012

EN 12697-24:2012 (E) 6 EN 12697-24, Bituminous mixtures — Test methods for hot mix asphalt — Part 24: Resistance to fatigue EN 12697-25, Bituminous mixtures — Test methods for hot mix asphalt — Part 25: Cyclic compression test EN 12697-26, Bituminous mixtures — Test methods for hot mix asphalt — Part 26: Stiffness EN 12697-27, Bituminous mixtures — Test methods for hot mix asphalt — Part 27: Sampling EN 12697-28, Bituminous mixtures — Test methods for hot mix asphalt — Part 28: Preparation of samples for determining binder content, water content and grading EN 12697-29, Bituminous mixtures — Test methods for hot mix asphalt — Part 29: Determination of the dimensions of a bituminous specimen EN 12697-30, Bituminous mixtures — Test methods for hot mix asphalt — Part 30: Specimen preparation by impact compactor EN 12697-31, Bituminous mixtures — Test methods for hot mix asphalt — Part 31: Specimen preparation by gyratory compactor EN 12697-32, Bituminous mixtures — Test methods for hot mix asphalt — Part 32: Laboratory compaction of bituminous mixtures by vibratory compactor EN 12697-33, Bituminous mixtures — Test methods for hot mix asphalt — Part 33: Specimen prepared by roller compactor EN 12697-34, Bituminous mixtures — Test methods for hot mix asphalt — Part 34: Marshall test EN 12697-35, Bituminous mixtures — Test methods for hot mix asphalt — Part 35: Laboratory mixing EN 12697-36, Bituminous mixtures — Test methods for hot mix asphalt — Part 36: Determination of the thickness of a bituminous pavement EN 12697-37, Bituminous mixtures — Test methods for hot mix asphalt — Part 37: Hot sand test for the adhesivity of binder on precoated chippings for HRA EN 12697-38, Bituminous mixtures — Test methods for hot mix asphalt — Part 38: Common equipment and calibration EN 12697-39, Bituminous mixtures — Test methods for hot mix asphalt — Part 39: Binder content by ignition EN 12697-40, Bituminous mixtures — Test methods for hot mix asphalt — Part 40: In situ drainability EN 12697-41, Bituminous mixtures — Test methods for hot mix asphalt — Part 41: Resistance to de-icing fluids EN 12697-42, Bituminous mixtures — Test methods for hot mix asphalt — Part 42: Amount of coarse foreign matters in reclaimed asphalt EN 12697-43, Bituminous mixtures — Test methods for hot mix asphalt — Part 43: Resistance to fuel EN 12697-44, Bituminous mixtures — Test methods for hot mix asphalt — Part 44: Crack propagation by semi-circular bending test EN 12697-45, Bituminous mixtures — Test methods for hot mix asphalt — Part 45: Saturation ageing tensile stiffness (SATS) conditioning test SIST EN 12697-24:2012

EN 12697-24:2012 (E) 7 EN 12697-46, Bituminous mixtures — Test methods for hot mix asphalt — Part 46: Low temperature cracking and properties by uniaxial tension tests EN 12697-47, Bituminous mixtures — Test methods for hot mix asphalt — Part 47: Determination of the ash content of natural asphalts prEN 12697-48, Bituminous mixtures — Test methods for hot mix asphalt — Part 48: Inter-layer bond strength1) prEN 12697-49, Bituminous mixtures — Test methods for hot mix asphalt — Part 49: Skid resistance of asphalt in the laboratory1) prEN 12697-50, Bituminous mixtures — Test methods for hot mix asphalt — Part 50: Scuffing resistance of surface course1) According to the CEN/CENELEC Internal Regulations, the national standards organizations 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, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.

1) In preparation. SIST EN 12697-24:2012

EN 12697-24:2012 (E) 8 1 Scope This European Standard specifies the methods for characterising the fatigue of bituminous mixtures using alternative tests, including bending tests and direct and indirect tensile tests. The tests are performed on compacted bituminous material under a sinusoidal loading or other controlled loading, using different types of specimens and supports. The procedure is used:

a) to rank bituminous mixtures on the basis of resistance to fatigue;

b) as a guide to relative performance in the pavement;

c) to obtain data for estimating the structural behaviour of the road; and

d) to judge test data according to specifications for bituminous mixtures. Because this European Standard does not impose a particular type of testing device, the precise choice of the test conditions depends on the possibilities and the working range of the device used. For the choice of specific test conditions, the requirements of the product standards for bituminous mixtures need to be respected. The applicability of this document is described in the product standards for bituminous mixtures. Results obtained from different test methods or using different failure criteria are not assured to be comparable. 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 12697-8, Bituminous mixtures — Test methods for hot mix asphalt — Part 8: Determination of void characteristics of bituminous specimens EN 12697-26:2011, Bituminous mixtures — Test methods for hot mix asphalt — Part 26: Stiffness EN 12697-27, Bituminous mixtures — Test methods for hot mix asphalt — Part 27: Sampling EN 12697-29, Bituminous mixtures — Test methods for hot mix asphalt — Part 29: Determination of the dimensions of a bituminous specimen EN 12697-31, Bituminous mixtures — Test methods for hot mix asphalt — Part 31: Specimen preparation by gyratory compactor EN 12697-33, Bituminous mixtures — Test methods for hot mix asphalt — Part 33: Specimen prepared by roller compactor 3 Terms, definitions, symbols and abbreviations For the purposes of this document, the following terms and definitions, symbols and abbreviations apply. SIST EN 12697-24:2012

EN 12697-24:2012 (E) 9 3.1 General 3.1.1 fatigue reduction of strength of a material under repeated loading when compared to the strength under a single load 3.1.2 conventional criteria of failure number of load applications, Nf/50, when the complex stiffness modulus Smix,0 has decreased to half its initial value 3.1.3 initial complex stiffness modulus complex stiffness modulus, Smix,0, after 100 load applications 3.1.4 fatigue life of a specimen number of cycles Ni,j,k corresponding to the conventional failure criterion at the set of test conditions k (temperature, frequency and loading mode)

Note 1 to entry: A loading mode could be constant deflection level, or constant force level, and or any other constant loading condition. 3.2 Two-point bending test on trapezoidal specimens 3.2.1 constant relative to maximum strain constant that enables the head displacement z of the trapezoidal specimen of dimensions [B, b, e, h], to which a bending strain level ε is applied, to be converted into maximum strain Note 1 to entry: The following formulae express Kε and its relationship with the parameters mentioned above: εε=×zK (1) ()[]bBBbBBbhbbBBKln)()()(×+−×−××−×=2222234ε (2) 3.2.2 Symbols Where a strain of 1 microstrain (µstrain) is equal to 10−6 by convention, the symbols are as follows: i is the index of the specimen for an element test (varies from 1 to n); hi is the height, in metres (m); Bi is the large base, in metres (m); bi is the small base, in metres (m); ei is the thickness, in metres (m); vi is the void content of the specimen i by geometric method, in percent (%); Kεi is the constant, relative to the maximum strain, in inverse metres (m–1); SIST EN 12697-24:2012

EN 12697-24:2012 (E) 10 zi is the amplitude of displacement imposed at the head of specimen i, in metres (m); εi is the maximum relative strain of specimen i corresponding with the displacement imposed at the head; Ni is the conventional fatigue life of specimen i; a is the ordinate of the fatigue line according to the formula log(N) = a + (1/b) log(ε); r2 is the linear correlation coefficient (log(Ni), log(εi)); 1/b is the slope of the fatigue line; log(ε) is the average value of log(εi); Slog(ε) is the standard deviation of log(εi); Slog(N) is the standard deviation of log(Ni); ε6 is the strain corresponding to 106 cycles; sN is the estimation of the residual standard deviation of the decimal logarithms of fatigue lives; ∆ε6 is the quality index of the test; n is the number of specimens. 3.3 Two-point bending test on prismatic shaped specimens 3.3.1 constants for consideration of the geometry of specimen constants that enable the strength of the head Pij of the specimen i of dimensions bi ,ei and hi, to which a bending strength is applied, to be converted to a maximum tension Note 1 to entry: The following formulae express Kε i and its relationship with the parameters mentioned above: maxjijiσσ=×PK (3) where Kσi is the constant for consideration of the geometry of specimen at constant strength; Pij is the amplitude of the strength, with which the head is applied, in Newtons (N); εjmax is the maximum relative strain of the specimen corresponding with the displacement imposed at the head; σjmax is the greatest relative tension of the specimen, corresponding to the strength, with which the head is applied. i2iii6ebhK×=σ (4) where SIST EN 12697-24:2012

EN 12697-24:2012 (E) 11 Kσi is the constant for consideration of the geometry of specimen at constant strength (factor in accordance with

EN 12697-26); bi is the base, in millimetres (mm); hi is the height, in millimetres (mm); ei is the width, in millimetres (mm). 3.3.2 Symbols Where a strain of 1 microstrain (µstrain) is equal to 10–6 by convention, the symbols are as follows: 3.3.2.1 Sample i hI is the height, in millimetres (mm); bI is (A) small base or (B) base, in millimetres (mm); eI is the thickness, in millimetres (mm); mI is the mass, in grams (g); vi% is the vacuum, achieved by the geometric method as a proportion of atmospheric pressure, in percent (%); Kσi is the constant for consideration of the geometry of specimen at constant strength, in inverse millimetres (mm–1). 3.3.2.2 Strength at head and greatest tension at specimen i at level of tension εj max Pij is the amplitude of the strength with which the head is applied, in Newtons (N); σj max is the greatest relative tension of the specimen, corresponding to the strength, with which the head is applied. 3.3.2.3 Fatigue life of a specimen i at the level of tension σj max Nij is the fatigue life. 3.3.2.4 Fatigue life relative to sample i at the strain level εj Nij is the conventional fatigue life. 3.3.2.5 Fatigue line pσ is the slope of fatigue line ln(σj max) = f (ln(Nij)); 6σˆ is the tension corresponding to 106 cycles, in megapascals (MPa); yxσs is the estimation of the residual standard deviation of the natural logarithms of fatigue lives; 6σ∆ˆ is the confidence of 6σˆfor a probability of 95 %; SIST EN 12697-24:2012

EN 12697-24:2012 (E) 12 N is the number of element tests (number of specimens at the level of tension σj max times the number of levels) where N = n*l; sN is the estimation of the standard deviation of ln(Nij). 3.3.2.6 Fatigue life of a series of n specimens (A) at a strain level εjmax or (B) at the level of tension σj max Nεjmax is the average number of cycles obtained at the level of tension σj max; l is the number at the level of tension σj max; n is the number of specimens at the level of tension σj max. 3.4 Three-point bending test on prismatic shaped specimens 3.4.1 Symbols The symbols are as follows: 2At is the amplitude of the approximate stress function, in megapascals (MPa); 2At is the amplitude of the approximate strain function, in megapascals (MPa); B is the measuring base of the extensometer, in millimetres (mm); Bt is the phase angle of the approximate stress function, in radians (rad); Bε is the phase angle of the approximate strain function, in radians (rad); Dc is the displacement at instant t, in microns (µm); 2D0 is the total amplitude of displacement function, in microns (µm); DDE is the density of dissipated energy, in megapascals (MPa) or megajoules per cubic metre (MJ/m3); DE(total) is the total density of dissipated energy throughout the whole test, in megajoules per cubic metre (MJ/m3); DDE (x)

is the density of dissipated energy at cycle x, in megajoules per cubic metre (MJ/m3); EXT is the instant extensometer signal, in millimetres (mm); L is the distance between supports, in millimetres (mm); MD is the dynamic modulus,

**...**

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Asphalt - Prüfverfahren für Heißasphalt - Teil 24: Beständigkeit gegen ErmüdungMélanges bitumineux - Méthodes d'essai pour mélange hydrocarboné à chaud - Partie 24: Résistance à la fatigueBituminous mixtures - Test methods for hot mix asphalt - Part 24: Resistance to fatigue93.080.20Materiali za gradnjo cestRoad construction materialsICS:Ta slovenski standard je istoveten z:FprEN 12697-24kSIST FprEN 12697-24:2011en,fr,de01-november-2011kSIST FprEN 12697-24:2011SLOVENSKI

STANDARD

kSIST FprEN 12697-24:2011

EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM

FINAL DRAFT

FprEN 12697-24

September 2011 ICS 93.080.20 Will supersede EN 12697-24:2004+A1:2007English Version

Bituminous mixtures - Test methods for hot mix asphalt - Part 24: Resistance to fatigue

Mélanges bitumineux - Méthodes d'essai pour mélange hydrocarboné à chaud - Partie 24: Résistance à la fatigue Asphalt - Prüfverfahren für Heißasphalt - Teil 24: Beständigkeit gegen Ermüdung This draft European Standard is submitted to CEN members for unique acceptance procedure. It has been drawn up by the Technical Committee CEN/TC 227.

If this draft becomes a European Standard, 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.

This draft European Standard was established by CEN 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, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.

Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without notice and shall not be referred to as a European Standard.

EUROPEAN COMMITTEE FOR STANDARDIZATION

COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre:

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B-1000 Brussels © 2011 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. FprEN 12697-24:2011: EkSIST FprEN 12697-24:2011

FprEN 12697-24:2011 (E) 2 Contents PageForeword .41Scope .82Normative references .83Terms, definitions, symbols and abbreviations .83.1General .83.2Two-point bending test on trapezoidal specimens .93.3Two-point bending test on prismatic shaped specimens . 103.4Three-point bending test on prismatic shaped specimens . 123.5Four-point bending test on prismatic shaped specimens . 133.6Symbols for indirect tensile test on cylindrical shaped specimens . 184Sample preparation . 194.1Age of the specimens . 194.2Drying of the specimen . 194.3Dimensions and bulk density of the specimens . 195Failure . 196Calculations . 197Summary of the procedures . 197.1Two-point bending test on trapezoidal specimens . 197.2Two-point bending test on prismatic shaped specimens . 197.3Three-point bending test on prismatic shaped specimens . 207.4Four-point bending test on prismatic shaped specimens . 207.5Indirect tensile test on cylindrical shaped specimens . 208Checking of the testing equipment . 209Test report . 21Annex A (normative)

Two-point bending test on trapezoidal shaped specimens . 22A.1Principle . 22A.2Equipment . 23A.3Specimen preparation . 23A.4Procedure . 26A.5Calculation and expression of results . 27A.6Test report . 28A.7Precision . 28Annex B (normative)

Two-point bending test on prismatic shaped specimens . 30B.1Principle . 30B.2Equipment . 30B.3Specimen preparation . 31B.4Procedure . 31B.5Calculation and expression of results . 32B.6Test report . 34B.7Precision . 34Annex C (normative)

Three-point bending test on prismatic shaped specimens . 35C.1Principle . 35C.2Equipment . 35C.3Specimen preparation . 36C.4Procedure . 36kSIST FprEN 12697-24:2011

FprEN 12697-24:2011 (E) 3 PageC.5Calculation and expression of results.37C.6Test report . 40C.7Precision. 41Annex D (normative)

Four-point bending test on prismatic shaped specimens . 42D.1Principle. 42D.2Equipment . 44D.3Specimen preparation . 45D.4Procedure . 46D.5Calculation and expression of results . 48D.6Test report . 48D.7Precision. 48Annex E (normative)

Indirect tensile test on cylindrical shaped specimens . 49E.1Principle. 49E.2Equipment . 49E.3Specimen preparation . 52E.4Procedure . 53E.5Calculation and reporting of results . 53E.6Test report . 56E.7Precision. 56Bibliography . 57

kSIST FprEN 12697-24:2011

FprEN 12697-24:2011 (E) 4 Foreword This document (FprEN 12697-24:2011) has been prepared by Technical Committee CEN/TC 227 “Road materials”, the secretariat of which is held by DIN. This document is currently submitted to the Unique Acceptance Procedure. This document will supersede EN 12697-24:2004+A1:2007. The significant changes from that document are: clarified in the scope that tests using different failure criteria are not comparable; definition of conventional criteria of fatigue for constant force deleted, leaving just constant displacement; definitions of the average and standard deviation of the fatigue life of a series of specimens for the two-point and four-point bending tests on prismatic specimens are removed; symbols for the frequency of the sinusoidal load applications and angular speed revised; requirements on age and drying of specimens added in the main text and removed from the individual annexes; limits on interpolation defined; alternative criterion given in a note; requirement for checking (rather than calibration) the test equipment added in the main text and removed from the individual annexes; requirement added for the test report to include information on the chosen test method, the used testing equipment, results of the last check on calibration of the testing equipment and the age of the specimen at the time of testing; the tolerance for the displacement of the trapezoidal specimen widened; measurements on the three-point bending test on prismatic specimens started after fewer cycles; note added on rotating the specimen in four-point bending test on prismatic specimens; the optional requirement for choosing frequency spectrum of initial complex (stiffness) moduli removed from the four-point bending test on prismatic specimens; the principle, equipment, procedure and calculations of the indirect tensile test on cylindrical specimens revised. This document is one of a series of standards as listed below: EN 12697-1, Bituminous mixtures — Test methods for hot mix asphalt — Part 1: Soluble binder content EN 12697-2, Bituminous mixtures — Test methods for hot mix asphalt — Part 2: Determination of particle size distribution kSIST FprEN 12697-24:2011

FprEN 12697-24:2011 (E) 5 EN 12697-3, Bituminous mixtures — Test methods for hot mix asphalt — Part 3: Binder recovery: Rotary evaporator EN 12697-4, Bituminous mixtures — Test methods for hot mix asphalt — Part 4: Binder recovery: Fractionating column EN 12697-5, Bituminous mixtures — Test methods for hot mix asphalt — Part 5: Determination of the maximum density EN 12697-6, Bituminous mixtures — Test methods for hot mix asphalt — Part 6: Determination of bulk density of bituminous specimens EN 12697-7, Bituminous mixtures — Test methods for hot mix asphalt — Part 7: Determination of bulk density of bituminous specimens by gamma rays EN 12697-8, Bituminous mixtures — Test methods for hot mix asphalt — Part 8: Determination of void characteristics of bituminous specimens EN 12697-10, Bituminous mixtures — Test methods for hot mix asphalt — Part 10: Compactibility EN 12697-11, Bituminous mixtures — Test methods for hot mix asphalt — Part 11: Determination of the affinity between aggregate and bitumen EN 12697-12, Bituminous mixtures — Test methods for hot mix asphalt — Part 12: Determination of the water sensitivity of bituminous specimens EN 12697-13, Bituminous mixtures — Test methods for hot mix asphalt — Part 13: Temperature measurement EN 12697-14, Bituminous mixtures — Test methods for hot mix asphalt — Part 14: Water content EN 12697-15, Bituminous mixtures — Test methods for hot mix asphalt — Part 15: Determination of the segregation sensitivity EN 12697-16, Bituminous mixtures — Test methods for hot mix asphalt — Part 16: Abrasion by studded tyres EN 12697-17, Bituminous mixtures — Test methods for hot mix asphalt — Part 17: Partial loss of porous asphalt specimen EN 12697-18, Bituminous mixtures — Test methods for hot mix asphalt — Part 18: Binder drainage EN 12697-19, Bituminous mixtures — Test methods for hot mix asphalt — Part 19: Permeability of specimen EN 12697-20, Bituminous mixtures — Test methods for hot mix asphalt — Part 20: Indentation using cube or Marshall specimens EN 12697-21, Bituminous mixtures — Test methods for hot mix asphalt — Part 21: Indentation using plate specimens EN 12697-22, Bituminous mixtures — Test methods for hot mix asphalt — Part 22: Wheel tracking EN 12697-23, Bituminous mixtures — Test methods for hot mix asphalt — Part 23: Determination of the indirect tensile strength of bituminous specimens EN 12697-24, Bituminous mixtures — Test methods for hot mix asphalt — Part 24: Resistance to fatigue EN 12697-25, Bituminous mixtures — Test methods for hot mix asphalt — Part 25: Cyclic compression test kSIST FprEN 12697-24:2011

FprEN 12697-24:2011 (E) 6 EN 12697-26, Bituminous mixtures — Test methods for hot mix asphalt — Part 26: Stiffness EN 12697-27, Bituminous mixtures — Test methods for hot mix asphalt — Part 27: Sampling EN 12697-28, Bituminous mixtures — Test methods for hot mix asphalt — Part 28: Preparation of samples for determining binder content, water content and grading EN 12697-29, Bituminous mixtures — Test methods for hot mix asphalt — Part 29: Determination of the dimensions of a bituminous specimen EN 12697-30, Bituminous mixtures — Test methods for hot mix asphalt — Part 30: Specimen preparation by impact compactor EN 12697-31, Bituminous mixtures — Test methods for hot mix asphalt — Part 31: Specimen preparation by gyratory compactor EN 12697-32, Bituminous mixtures — Test methods for hot mix asphalt — Part 32: Laboratory compaction of bituminous mixtures by vibratory compactor EN 12697-33, Bituminous mixtures — Test methods for hot mix asphalt — Part 33: Specimen prepared by roller compactor EN 12697-34, Bituminous mixtures — Test methods for hot mix asphalt — Part 34: Marshall test EN 12697-35, Bituminous mixtures — Test methods for hot mix asphalt — Part 35: Laboratory mixing EN 12697-36, Bituminous mixtures — Test methods for hot mix asphalt — Part 36: Determination of the thickness of a bituminous pavement EN 12697-37, Bituminous mixtures — Test methods for hot mix asphalt — Part 37: Hot sand test for the adhesivity of binder on precoated chippings for HRA EN 12697-38, Bituminous mixtures — Test methods for hot mix asphalt — Part 38: Common equipment and calibration EN 12697-39, Bituminous mixtures — Test methods for hot mix asphalt — Part 39: Binder content by ignition EN 12697-40, Bituminous mixtures — Test methods for hot mix asphalt — Part 40: In situ drainability EN 12697-41, Bituminous mixtures — Test methods for hot mix asphalt — Part 41: Resistance to de-icing fluids EN 12697-42, Bituminous mixtures — Test methods for hot mix asphalt — Part 42: Amount of coarse foreign matters in reclaimed asphalt EN 12697-43, Bituminous mixtures — Test methods for hot mix asphalt — Part 43: Resistance to fuel EN 12697-44, Bituminous mixtures — Test methods for hot mix asphalt — Part 44: Crack propagation by semi-circular bending test prEN 12697-45, Bituminous mixtures — Test methods for hot mix asphalt — Part 45: Saturation ageing tensile stiffness (SATS) conditioning test prEN 12697-46, Bituminous mixtures — Test methods for hot mix asphalt — Part 46: Low temperature cracking and properties by uniaxial tension tests EN 12697-47, Bituminous mixtures — Test methods for hot mix asphalt — Part 47: Determination of the ash content of natural asphalts kSIST FprEN 12697-24:2011

FprEN 12697-24:2011 (E) 7 prEN 12697-48, Bituminous mixtures — Test methods for hot mix asphalt — Part 48: Inter-layer bond strength1) prEN 12697-49, Bituminous mixtures — Test methods for hot mix asphalt — Part 49: Skid resistance of asphalt in the laboratory1) prEN 12697-50, Bituminous mixtures — Test methods for hot mix asphalt — Part 50: Scuffing resistance of surface course1)

1) In preparation kSIST FprEN 12697-24:2011

FprEN 12697-24:2011 (E) 8 1 Scope This European Standard specifies the methods for characterising the fatigue of bituminous mixtures by alternative tests, including bending tests and direct and indirect tensile tests. The tests are performed on compacted bituminous material under a sinusoidal loading or other controlled loading, using different types of specimens and supports. The procedure is used to rank bituminous mixtures on the basis of resistance to fatigue, as a guide to relative performance in the pavement, to obtain data for estimating the structural behaviour in the road and to judge test data according to specifications for bituminous mixtures. Because this European Standard does not impose a particular type of testing device, the precise choice of the test conditions depends on the possibilities and the working range of the used device. For the choice of specific test conditions, the requirements of the product standards for bituminous mixtures need to be respected. The applicability of this document is described in the product standards for bituminous mixtures. Results obtained from different test methods or using different failure criteria are not assured to be comparable. 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 12697-6, Bituminous mixtures — Test methods for hot mix asphalt — Part 6: Determination of bulk density of bituminous specimen EN 12697-8, Bituminous mixtures — Test methods for hot mix asphalt — Part 8: Determination of void characteristics of bituminous specimens EN 12697-26:2011, Bituminous mixtures — Test methods for hot mix asphalt — Part 26: Stiffness EN 12697-27, Bituminous mixtures — Test methods for hot mix asphalt — Part 27: Sampling EN 12697-29, Bituminous mixtures — Test methods for hot mix asphalt — Part 29: Determination of the dimensions of bituminous specimen EN 12697-31, Bituminous mixtures — Test methods for hot mix asphalt — Part 31: Specimen preparation by gyratory compactor EN 12697-33, Bituminous mixtures — Test methods for hot mix asphalt — Part 33: Specimen prepared by roller compactor 3 Terms, definitions, symbols and abbreviations For the purposes of this document, the following terms and definitions, symbols and abbreviations apply. 3.1 General 3.1.1 fatigue reduction of strength of a material under repeated loading when compared to the strength under a single load kSIST FprEN 12697-24:2011

FprEN 12697-24:2011 (E) 9 3.1.2 conventional criteria of failure number of load applications, Nf/50, when the complex stiffness modulus Smix,0 has decreased to half its initial value 3.1.3 initial complex stiffness modulus complex stiffness modulus, Smix,0, after 100 load applications 3.1.4 fatigue life of a specimen number of cycles Ni,j,k corresponding with the conventional failure criterion at the set of test conditions k (temperature, frequency and loading mode; e.g. constant deflection level, or constant force level, and or any other constant loading condition) 3.2 Two-point bending test on trapezoidal specimens 3.2.1 constant relative to maximum strain constant that enables the head displacement z of the trapezoidal specimen of dimensions [B, b, e, h], to which a bending strain level ε is applied, to be converted into maximum strain NOTE Kε and its relationship with the parameters mentioned above is the following: εε=×zK (1) ()[]bBBbBBbhbbBBKln)()()(×+−×−××−×=2222234ε (2) 3.2.2 Symbols The symbols are as follows, with a strain of 1 microstrain (µstrain) being equal to 10−6 by convention: i is the index of the specimen for an element test (varies from 1 to n); hi is the height, in metres (m); Bi is the large base, in metres (m); bi is the small base, in metres (m); ei is the thickness, in metres (m); vi is the void content of the specimen i by geometric method, in per cent (%); Kεi is the constant, relative to the maximum strain, in inverse metres (m–1); zi is the amplitude of displacement imposed at the head of specimen i, in metres (m); εi is the maximum relative strain of specimen i corresponding with the displacement imposed at the head; Ni is the conventional fatigue life of specimen i; kSIST FprEN 12697-24:2011

FprEN 12697-24:2011 (E) 10 a is the ordinate of the fatigue line according to the equation log(N) = a + (1/b) log(ε); r2 is the linear correlation coefficient (log(Ni), log(εi)); 1/b is the slope of the fatigue line; log(ε) is the average value of log(εi); Slog(ε) is the standard deviation of log(εi); Slog(N) is the standard deviation of log(Ni); ε6 is the strain corresponding with 106 cycles; sN is the estimation of the residual standard deviation of the decimal logarithms of fatigue lives; ∆ε6 is the quality index of the test; n is the number of specimens. 3.3 Two-point bending test on prismatic shaped specimens 3.3.1 constants for consideration of the geometry of specimen constants that enable the strength of the head Pij of the specimen i of dimensions bi ,ei and hi, to which a bending strength is applied, to be converted to a maximum tension NOTE Kε i, and its relationship with the parameters mentioned above, is as follows: maxjijiσσ=×PK (3) where Kσi is the constants for consideration of the geometry of specimen at constant strength; Pij is the amplitude of the strength, with which the head is applied, in Newton (N); εjmax is the maximum relative strain of the specimen corresponding with the displacement imposed at the head; σjmax the greatest relative tension of the specimen, corresponding to the strength, with which the head is applied. i2iii6ebhK×=σ (4) where Kσi is the constant for consideration of the geometry of specimen at constant strength (factor in accordance to

EN 12697-26); bi is the base, in millimetre (mm); hi is the height, in millimetre (mm); ei is the width, in millimetre (mm). kSIST FprEN 12697-24:2011

FprEN 12697-24:2011 (E) 11 3.3.2 Symbols The symbols are as follows, with a strain of 1 microstrain (µstrain) being equal to 10–6 by convention: 3.3.2.1 Sample i hI is the height, in millimetres (mm); bI is (A) small base or (B) base, in millimetres (mm); eI is the thickness, in millimetres (mm); mI is the mass, in grams (g); vi% is the vacuum achieved by the geometric method as a proportion of atmospheric pressure, in per cent (%); Kσi is the constant for consideration of the geometry of specimen at constant strength, in inverse millimetres (mm–1). 3.3.2.2 Strength at head and greatest tension at specimen i at level of tension εj max Pij is the amplitude of the strength with which the head is applied, in Newtons (N); σj max is the greatest relative tension of the specimen, corresponding to the strength, with which the head is applied. 3.3.2.3 Fatigue life of a specimen i at the level of tension σj max Nij is the fatigue life. 3.3.2.4 Fatigue life relative to sample i at the strain level εj Nij is the conventional fatigue life. 3.3.2.5 Fatigue line pσ is the slope of fatigue line ln(σj max) = f (ln(Nij)); 6σˆ is the tension corresponding with 106 cycles, in megapascals (MPa); yxσs is the estimation of the residual standard deviation of the natural logarithms of fatigue lives; 6σ∆ˆ is the confidence of 6σˆfor a probability of 95 %; N is the number of element tests (number of specimens at the level of tension σj max times the number of levels) where N = n*l; sN is the estimation of the standard deviation of ln(Nij). 3.3.2.6 Fatigue life of a series of n specimens (A) at a strain level εjmax or (B) at the level of tension σj max Nεjmax is the average number of cycles obtained at the level of tension σj max; kSIST FprEN 12697-24:2011

FprEN 12697-24:2011 (E) 12 l is the number at the level of tension σj max; n is the number of specimens at the level of tension σj max. 3.4 Three-point bending test on prismatic shaped specimens 3.4.1 Symbols The symbols are as follows: 2At is the amplitude of the approximate stress function, in megapascals (MPa); 2At is the amplitude of the approximate strain function; B is the measuring base of the extensometer, in millimetres (mm); Bt is the phase angle of the approximate stress function, in radians (rad); Bε is the phase angle of the approximate strain function, in radians (rad); Dc is the displacement at instant t, in microns (µm); 2D0 is the total amplitude of displacement function, in microns (µm); DDE is the density of dissipated energy, in megapascals (MPa) or megajoules per cubic metre (MJ/m3); DE(total) is the total density of dissipated energy throughout the whole test, in megajoules per cubic metre (MJ/m3); DDE (x)

is the density of dissipated energy at cycle x, in megajoules per cubic metre (MJ/m3); EXT is the instant extensometer signal, in millimetres (mm); L is the distance between supports, in millimetres (mm); MD is the dynamic modulus, in megapascals (MPa); N is the number of cycle at end of test; P is the instant load, in megapascals (MPa); W is the total density of dissipated energy throughout the whole test, in megajoules per cubic metre (MJ/m3); b is the width of specimen, in millimetres (mm); e is the thickness of specimen, in millimetres (mm); f is the wave frequency, in Hertz (Hz); m is (N − 200)/500; t is the time, in seconds (s); ε is the instant strain or half cyclic amplitude of strain function at cycle 200; kSIST FprEN 12697-24:2011

FprEN 12697-24:2011 (E) 13 εa is the approximate strain function value; εc is the cyclic amplitude of strain function; ε6 is the strain at 106 cycles; σ is

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