1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN 12697-44:2010Bituminous mixtures Testmethods for hot mix asphaltPart 44: Crack propagation by semi-circularbending testBS EN 12697-44:2010 BRITISH STANDARDNational foreword
2、This British Standard is the UK implementation of EN 12697-44:2010.The UK participation in its preparation was entrusted to TechnicalCommittee B/510/1, Asphalt products.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport
3、to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. BSI 2010ISBN 978 0 580 63150 4ICS 93.080.20Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards P
4、olicy and Strategy Committee on 31 October 2010.Amendments issued since publicationDate Text affectedBS EN 12697-44:2010EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 12697-44 September 2010 ICS 93.080.20 English Version Bituminous mixtures - Test methods for hot mix asphalt - Part 44: Crack p
5、ropagation by semi-circular bending test Mlanges bitumineux - Mthodes dessai pour mlange hydrocarbon chaud - Partie 44 : Propagation de fissure par essai de flexion dun bloc semi-circulaire Asphalt - Prfverfahren fr Heiasphalt - Teil 44: Bestimmung der Rissausbreitung mittels Halbzylinder-Biegeversu
6、ch This European Standard was approved by CEN on 28 August 2010. 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 r
7、eferences concerning such national standards 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 translation under the responsibility of a CEN mem
8、ber into its own language and notified to the CEN 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, Irelan
9、d, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17,
10、 B-1000 Brussels 2010 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 12697-44:2010: EBS EN 12697-44:2010EN 12697-44:2010 (E) 2 Contents Page Foreword 31 Scope 62 Normative references 63 Terms and definitions .64 Symbols 75 Princip
11、le 76 Apparatus .86.1 Test Machine 86.2 Load cell or other force-measuring gauge 86.3 Deformation gauge 86.4 Roller bearings .86.5 Specimen bearing strips .96.6 Metal loading strip L 96.7 Monitoring equipment .96.8 Sliding callipers .96.9 Climatic chamber .96.10 Cutting machine .97 Sample preparatio
12、n 107.1 Manufacture . 107.2 Dimensional check . 107.3 Storage . 118 Procedure 119 Calculations . 1210 Test report . 1411 Precision data . 14Bibliography . 15BS EN 12697-44:2010 EN 12697-44:2010 (E) 3 Foreword This document (EN 12697-44:2010) has been prepared by Technical Committee CEN/TC 227 “Road
13、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 March 2011, and conflicting national standards shall be withdrawn at the latest by March 2011.
14、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 European Standard is one of a series of standards as listed below: EN 12697-1, Bi
15、tuminous 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: Bitumen recovery: Rotary eva
16、porator EN 12697-4, Bituminous mixtures Test methods for hot mix asphalt Part 4: Bitumen 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
17、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 charact
18、eristics of bituminous specimens EN 12697-9, Bituminous mixtures Test methods for hot mix asphalt Part 9: Determination of the reference density EN 12697-10, Bituminous mixtures Test methods for hot mix asphalt Part 10: Compactability EN 12697-11, Bituminous mixtures Test methods for hot mix asphalt
19、 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 measu
20、rement EN 12697-14, Bituminous mixtures Test methods for hot mix asphalt Part 14: Water content BS EN 12697-44:2010EN 12697-44:2010 (E) 4 EN 12697-15, Bituminous mixtures Test methods for hot mix asphalt Part 15: Determination of the segregation sensitivity EN 12697-16, Bituminous mixtures Test meth
21、ods for hot mix asphalt Part 16: Abrasion by studded tyres EN 12697-17, Bituminous mixtures Test methods for hot mix asphalt Part 17: Particle 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 T
22、est 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 12
23、697-22, 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 Par
24、t 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 1
25、2697-28, 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, Bit
26、uminous 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: Laborat
27、ory compaction of bituminous mixtures by a 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 Te
28、st 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
29、binder on precoated chippings for HRA BS EN 12697-44:2010 EN 12697-44:2010 (E) 5 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-
30、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 matter i
31、n 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 asp
32、halt 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: Determi
33、nation of the ash content of natural asphalts prEN 12697-48, Bituminous mixtures Test methods for hot mix asphalt Part 48: Inter-layer bond strength (in preparation) prEN 12697-49, Bituminous mixtures Test methods for hot mix asphalt Part 49: Skid resistance of asphalt in the laboratory (in preparat
34、ion) prEN 12697-50, Bituminous mixtures Test methods for hot mix asphalt Part 50: Scuffing resistance of surface course (in preparation) According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: A
35、ustria, 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 the United Kingdo
36、m. BS EN 12697-44:2010EN 12697-44:2010 (E) 6 1 Scope This European Standard specifies the Semi-Circular Bending (SCB) test method to determine the tensile strength or fracture toughness of an asphalt mixture for the assessment of the potential for crack propagation. The results of the test can be us
37、ed to calculate: the maximum load that the material containing a notch (crack) can resist before failure; when the presence of a notch is critical. It should be noted that the test only describes a method to determine the resistance to crack propagation of an asphalt mixture. The crack propagation p
38、hase describes the second part of failure mechanism during dynamic loading. The first phase, which is the crack initiation phase, is mainly covered by the fatigue test (EN 12697-24). 2 Normative references The following referenced documents are indispensable for the application of this document. For
39、 dated referenced, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 12697-27, Bituminous mixtures Test methods for hot mix asphalt Part 27: Sampling EN 12697-31, Bituminous mixtures Test methods for hot mix a
40、sphalt 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 EN 12697-35, Bituminous mixtures Test methods for hot mix asphalt Part 35: Laboratory mixing 3 Terms and definitions For the pur
41、poses of this document, the following terms and definitions apply. 3.1 test piece sample obtained by sawing an asphalt cylinder through a diameter 3.2 strain relative deformation of the test piece 3.3 stress force per unit area 3.4 horizontal stress tensile stress prevailing at the base of the test
42、piece 3.5 tensile strength strength of the material under tensile loading BS EN 12697-44:2010EN 12697-44:2010 (E) 7 3.6 fracture toughness resistance to failure of the test piece by breaking 4 Symbols a Notch depth in millimetres (mm) D Diameter in millimetres (mm) f(a/W) Geometric factor F Force in
43、 newtons (N) FmaxMaximum force in newtons (N) KIcFracture toughness in newtons per millimetre to the power of 1,5 (N/mm1,5) t Thickness in millimetres (mm) W Vertical displacement at maximum force in millimetres (mm) maxStrain at maximum force in percent (%) Stress in newtons per square millimetre (
44、N/mm) horHorizontal stress in newtons per square millimetre (N/mm) maxMaximum stress at failure in newtons per square millimetre (N/mm) 5 Principle A half cylinder test piece with a centre crack is loaded in three-point bending in such a way that the middle of the base of the test piece is subjected
45、 to a tensile stress. During the test, the deformation increases at a constant rate of 5 mm/min. The corresponding load increases to a maximum value, Fmax, that is directly related to the fracture toughness of the test sample. In Figure 1 an example of the test frame and specimen is given. BS EN 126
46、97-44:2010EN 12697-44:2010 (E) 8 Dimensions in millimetres Figure 1 Example of the test frame and specimen for the SCB-test 6 Apparatus 6.1 Test Machine The machine should have a range of at least 50 kN and have a drive with which a constant deformation rate of (5,0 0,2) mm/min is maintained during
47、the test. 6.2 Load cell or other force-measuring gauge Capable of measuring the load with an accuracy of 0,2 kN. 6.3 Deformation gauge Capable of measuring the deformation to an accuracy of 0,01 mm. 6.4 Roller bearings Capable of rotating on its axis with a support length (centre to centre) of (120,
48、0 0,5) mm and a diameter of (35,0 0,5) mm, as shown in Figure 2. BS EN 12697-44:2010EN 12697-44:2010 (E) 9 Dimensions in millimetres Key 1 Roller bearings 2 Loading strip Figure 2 Schematic of semi-circular bend test 6.5 Specimen bearing strips Between specimen and roller bearing, a metal specimen bearing strip (two per specimen) of dimensions (52 1) mm by (20 1) mm by (1,0 0,2) mm (L W H) shall be placed. The centre of each bearing strip shall be directly above the centre of the each roller bearing. 6.6 Metal loading strip L With a length of at least the thicknes
