1、Designation: D7942 15Standard Specification forThermoplastic Pavement Markings in Non Snow PlowAreas1This standard is issued under the fixed designation D7942; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revisi
2、on. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers a reflectorized thermoplasticbased pavement striping material of the class that is applied tothe road s
3、urface in a molten state by screed/extrusion or ribbonextrusion means. Retroreflectivity of the pavement markingcompound is achieved initially by surface application ofretroreflective optics at the time of pavement marking appli-cation. Upon cooling to normal pavement temperature, thepavement markin
4、g material produces an adherent reflectorizedstripe of specified thickness and width capable of resistingdeformation by traffic. The pavement marking compoundincludes retroreflective optics (glass beads or composite optics,or both) that are incorporated into the material at the time ofmanufacture th
5、at provide retroreflective properties during theservice life of the material.1.1.1 This specification is limited to:1.1.1.1 Longitudinal applications in non snow plow areas,1.1.1.2 Standard (non-profile) pavement markingapplications, and1.1.1.3 Applications on smooth asphalt or concrete surfaces.Asp
6、halt seal coat applications, which use large aggregateresulting in a very rough, open grade finish, are excluded fromthis specification.1.1.2 This specification includes:1.1.2.1 Compositional and physical property requirementsof the thermoplastic pavement marking material,1.1.2.2 Requirements for th
7、e optics that are used to reflec-torize the thermoplastic pavement marking material afterapplication,1.1.2.3 Field performance requirements for the installedthermoplastic pavement markings, and1.1.2.4 Material application requirements.1.2 The values stated in inch-pounds units are to be re-garded as
8、 the standard except where noted in the document.The values given in parentheses are mathematical conversionsto SI units that are provided for information only and are notconsidered standard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It
9、is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D36 Test Method for Softening Point of Bitumen (Ring-and-Ball Apparatus)D92 Test
10、Method for Flash and Fire Points by ClevelandOpen Cup TesterD4960 Test Method for Evaluation of Color for Thermoplas-tic Traffic Marking MaterialsD6628 Specification for Color of Pavement Marking Mate-rialsD7307 Practice for Sampling of Thermoplastic Traffic Mark-ing MaterialsD7308 Practice for Samp
11、le Preparation of ThermoplasticTraffic Marking MaterialsD7585 Practice for Evaluating Retroreflective PavementMarkings Using Portable Hand-Operated InstrumentsD7735 Test Method for Type A Durometer Hardness Testingof Road Marking Thermoplastic at Elevated TemperaturesE313 Practice for Calculating Ye
12、llowness and WhitenessIndices from Instrumentally Measured Color CoordinatesE1710 Test Method for Measurement of RetroreflectivePavement Marking Materials with CEN-Prescribed Ge-ometry Using a Portable RetroreflectometerG155 Practice for Operating Xenon Arc Light Apparatus forExposure of Non-Metalli
13、c Materials2.2 AASHTO Standards:3AASHTO M247 Standard Specification for Glass BeadsUsed in Traffic PaintsAASHTO T250 Standard Method of Test for Thermoplastic1This specification is under the jurisdiction of ASTM Committee D04 on Roadand Paving Materials and is the direct responsibility of Subcommitt
14、ee D04.38 onHighway Traffic Control Materials.Current edition approved Jan. 1, 2015. Published January 2015. DOI: 10.1520/D7942-15.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume informa
15、tion, refer to the standards Document Summary page onthe ASTM website.3Available from American Association of State Highway and TransportationOfficials (AASHTO), 444 N. Capitol St., NW, Suite 249, Washington, DC 20001,http:/www.transportation.org.Copyright ASTM International, 100 Barr Harbor Drive,
16、PO Box C700, West Conshohocken, PA 19428-2959. United States1Traffic Line Material3. Terminology3.1 Definitions:3.1.1 bindermixture of rosins, synthetic resins, waxes,polymers, and plasticizers that form the continuous phase inthe Pavement Marking Compound.3.1.2 pavement marking compounda homogeneou
17、s mix-ture of binder, fillers, extenders, pigments and intermixedretroreflective optics.3.1.3 retroreflective optics:3.1.3.1 glass beadsspherical glass manufactured for usewith pavement marking materials to provide retroreflectiveproperties to the marking, allowing them to be visible whenviewed at n
18、ight under automobile headlights.(1) small glass beadsalso referred to as standard glassbeads. This can refer to a number of products of various sizes,but as defined in this document it refers to a glass bead productmeeting the requirements ofAASHTO M247 Type 1 or Type 2.(2) large glass beadsthese g
19、lass beads meet the require-ments of AASHTO M247 Type 3, Type 4, or Type 5 as calledfor in the specification.(3) high refractive index glass beadsthese glass beadstypically meet the requirements of AASHTO M247 Type 1 orType 2 except the refractive index of the glass bead is between1.90 and 1.95.3.1.
20、3.2 composite opticsA multi-component retroreflec-tive particle comprised of a pigmented core (typically white oryellow) combined with very small glass or ceramic beadshaving a refractive index of between 1.90 and 2.4).3.1.3.3 non AASHTO glass beadsA manufacturer mayprovide a product outside the req
21、uirements found under section3.1.3.1 in which case the performance requirements of thisspecification must still be met.3.1.4 thermoplastic pavement markingsa pavement mark-ing compound brought to a molten state by heating to themanufacturers recommended temperature under agitation andthen applied to
22、 the pavement while in the molten state.Retroreflective optics are applied (dropped on) to the surface ofthe molten marking immediately after application to provideinitial retroreflectivity.4. Classification4.1 The thermoplastic pavement markings are classified intocategories with specific retrorefl
23、ectivity performance levels.See 9.6.4.2 The annex contains application recommendations fortypical installations to meet each performance class.4.3 The thermoplastic pavement markings can be providedwith a contrast marking process consisting of a black thermo-plastic pavement marking that improves th
24、e visual markingcontrast for daytime visibility.5. Ordering Information5.1 The purchaser must specify the Pavement MarkingClass when ordering. In addition the purchaser has the optionof requiring a contrast marking application.6. Materials and Manufacture6.1 The thermoplastic material shall be avail
25、able in white,yellow and black.6.2 The thermoplastic material shall be homogeneouslycomposed of pigment, filler, resins and optics.6.3 Glass Beads General RequirementsGlass beads shallprovide the marking with good night visibility without com-promising day visibility and be of a composition designed
26、 to behighly resistant to traffic wear and to the effects of weathering.6.4 Intermix Glass BeadsThe glass beads shall conform tothe requirements of AASHTO M247 Type 1, Type 2, or Type3 and shall be either uncoated or have an adhesion promotingcoating.6.5 Drop-on Glass BeadsThe drop-on beads shall me
27、etthe requirements of AASHTO M247 as required in thisspecification. When a double drop application of glass beads isrequired the larger beads shall be placed on the top surface ofthe thermoplastic first followed by the application of thesmaller beads.6.5.1 Specific PropertiesThe AASHTO M247 Type 3,T
28、ype 4, and Type 5 glass beads used for drop-on beads shallhave an adhesion promoting coating. AASHTO M247 Type 1and Type 2 glass spheres used for drop-on beads shall have acoating which will provide enhanced adhesion, moistureresistance, and proper embedment in the pavement marking.6.6 Composite Opt
29、icsThe composite optics shall be pro-vided according to the manufacturers specifications.6.7 The thermoplastic material shall not deteriorate oncontact with sodium chloride, calcium chloride or other de-icing chemicals or because of oil content of paving materials oroil droppings.6.8 CompositionThe
30、pigment, beads and filler shall beuniformly dispersed in the resin. The material shall be freefrom all skins, dirt and foreign objects.6.9 Set TimeWhen applied at a temperature range of 4126 12F (211 6 7C) and thickness of up to 0.125 in. (4.736mm) the material shall set to bear traffic in not more
31、than 2minutes when the air temperature is 50 6 3F (10 6 2C) andnot more than 10 minutes when the air temperature is 90 6 3F(32 6 2C).6.10 Storage LifeThermoplastic material furnished ingranular and block form shall meet the above requirements fora minimum period of 1 year. The thermoplastic must mel
32、tuniformly with no evidence of skins or unmelted particlesduring this one year period. Material not meeting the aboverequirements shall be replaced by the manufacturer.7. Chemical Composition7.1 Composition of the Thermoplastic Pavement MarkingMaterial (percent by weight)See Table 1.8. Physical Prop
33、erties8.1 Laboratory Properties:8.1.1 ColorThe thermoplastic materials after heating for 4h 6 5 min at 425 6 3F (218 6 2C) under agitation shall meetD7942 152the following requirements when tested according to TestMethod D4960 using a CIE 2 degree standard observer andstandard illuminant D65. Yellow
34、ness index shall be calculatedaccording to Practice E313.8.1.1.1 White:(a) Daylight Reflectance at 45/0: 75 % minimum(b) Yellowness Index at 45/0: 12 Maximum8.1.1.2 Yellow:(a) Daylight reflectance at 45/0: 42 to 56 %(b) The initial daytime CIE chromaticity for yellow mate-rials without drop-on retro
35、reflective optics shall fall within thefollowing coordinates:Initial Yellow Daytime Chromaticity Coordinates (Corner Points)1234x 0.490 0.560 0.460 0.420y 0.510 0.440 0.400 0.440(c) Color Stability after Accelerated Weathering ASTMDesignation: Practice G155, Table X3.1 Cycle I, 1500 hexposure time.
36、Prepare sample by dipping a sheet aluminumpanel into the molten thermoplastic and removing it to obtaina 0.06 to 0.120 in. (1.5 to 3 mm) coating thickness ofthermoplastic on the panel. Place the panel in the weatheringapparatus for 1500 h. After accelerated weathering, measurethe Yellow Color or Yel
37、lowness Index. Material shall meet thecolor stability requirements below after this exposure. Thisrequirement is not intended to be predictive of the 3 to 5 yearservice life of the marking but can be used as a screening toolto identify materials that will fail.White Yellowness Index 20 MaximumYellow
38、 Daytime Chromaticity Coordinates (after accelerated weathering)1234x 0.490 0.560 0.460 0.420y 0.510 0.440 0.400 0.4408.1.2 Cracking Resistance at Low TemperatureThe mate-rial shall show no cracks when tested in accordance toAASHTO T250.8.1.3 Softening PointAfter heating the thermoplastic ma-terial
39、for 4 h 6 5 min at 425 6 3F (218 6 2C) and testingin accordance with Test Method D36, the materials shall havea softening point of 215 6 15F (102.5 6 9.5C).8.1.4 Indentation ResistanceThe hardness shall be be-tween 40 and 75 units after 15 s when tested in accordance toTest Method D7735. The duromet
40、er and the sample shall bemaintained at 115F (46C).8.1.5 Flash PointThe thermoplastic material shall have aflashpoint of no less than 500F (260C) when tested inaccordance with Test Method D92 COC.9. Performance Requirements9.1 Installed pavement markings shall meet the followingservice life requirem
41、ents:Traffic Volume (AADTpl)AMinimum Years of Service Life25000 3AAADTpl is defined as the annual average daily traffic count per traffic lane.9.2 The service life of the installed markings shall bedefined by the following field performance criteria:9.3 Daytime Color (during service life)The marking
42、sshall meet the requirements of Specification D6628 with theexception of “Y” (reflectance).9.4 Night Time Color (during service life)The markingsshall meet the requirements of Specification D6628.9.5 DurabilityDefined as no more than 10 % loss (visibledaytime road presence) in any 1000 ft section of
43、 continuous orbroken pavement markings. Any markings installed less than 6in. from a construction joint are not covered in this specifica-tion.9.6 Retroreflectivity (180 days)The minimum dry retrore-flectivity of the markings when tested 180 days or less afterinstallation shall be as follows when te
44、sted according to TestMethod E1710:Dry Retroreflectivity (Test MethodE1710)AClass 1 Class 2 Class 3White (mcd/m2/lux) 300 450 800Yellow (mcd/m2/lux) 200 350 525AThe values presented for the coefficient of retroreflected luminance (RL)arepresented in SI units, which are the accepted worldwide norm fo
45、r expressing thisvalue, rather than in inch-pounds.9.7 Retroreflectivity (retained)The minimum dry retrore-flectivity of the markings of all classes when tested from 181days after installation through the end of service life of themarkings shall be as follows when tested according to TestMethod E171
46、0:White: 150 mcd/m2/luxYellow: 125 mcd/m2/luxNOTE 1The values presented for the coefficient of retroreflectedluminance (RL) are presented in SI units, which are the acceptedworldwide norm for expressing this value, rather than in inch-pounds.9.8 In considering compliance to the performance require-m
47、ents of this specification any area where the markings aretracked, contaminated by foreign material, damaged by un-usual traffic patterns or natural or man-made disasters shall beexcluded.10. Installation Requirements10.1 Pavement Surface RequirementsThe pavement sur-face shall be new or meet the re
48、quirements ofAnnex A1.3 priorTABLE 1 Composition of the Thermoplastic Pavement MarkingMaterial (percent by weight)Component White Yellow BlackBinderB20.0 min. 20.0 min. 20.0 min.Intermix Retroreflective OpticsC40.0 min. 40.0 min. Titanium Dioxide (ASTM Type II) 10.0 min. Yellow and Black Pigments AA
49、AAmount of yellow and black pigment, calcium carbonate and inert fillers shall beat the option of the manufacturer, providing all other requirements of thisspecification are met. The thermoplasticmaterial shall comply with all applicableFederal requirements found in RCRA (Resource Conservation and Recovery Act).BThe binder shall consist of a mixture of synthetic resins, polymers, andplasticizers. The purchaser shall have the option of requiring the binder system tobe either an alkyd or a hydrocarbon based system.CThe retr
