1、Designation: D8161 17Standard Test Method forImpact Resistance of Thermoplastic Pavement MarkingMaterials over a Highway Substrate by Means of a StrikerImpacted by a Falling Weight1This standard is issued under the fixed designation D8161; the number immediately following the designation indicates t
2、he year oforiginal adoption or, in the case of revision, the year of last revision. 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 test method covers the sample preparation ov
3、er aroad-type substrate and test methodology of thermoplasticpavement marking materials similar to the “Gardner Impact”method as listed in Test Method D5420.1.2 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI unit
4、s that are provided for information onlyand are not considered standard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety, health, and environmental practices
5、 and deter-mine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Rec
6、om-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D883 Terminology Relating to PlasticsD2794 Test Method for Resistance of Organic Coatings tothe Effects of Rapid Deformation (Impact)D4796 Test Method for Bond S
7、trength of ThermoplasticPavement Marking MaterialsD5420 Test Method for Impact Resistance of Flat, RigidPlastic Specimen by Means of a Striker Impacted by aFalling Weight (Gardner Impact)D5628 Test Method for Impact Resistance of Flat, RigidPlastic Specimens by Means of a Falling Dart (Tup orFalling
8、 Mass)D7307 Practice for Sampling of Thermoplastic Traffic Mark-ing MaterialsD7308 Practice for Sample Preparation of ThermoplasticPavement Marking MaterialsE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE284 Terminology of AppearanceE691 Practice for Conducting an Interlab
9、oratory Study toDetermine the Precision of a Test Method3. Terminology3.1 Definitions:3.1.1 The terms and definitions in Terminology D883 andE284 apply to this method.3.2 Definitions of Terms Specific to This Standard:3.2.1 failure (of test specimen), nthe presence of any crackor split created by th
10、e impact of the falling weight that can beseen by the naked eye under normal laboratory lightingconditions.3.2.2 Falling Weight (Gardner) Impact Tester, nimpacttester designed as described in Test Method D5420.3.2.3 thermoplastic pavement marking, na highly filled100 % total solids highway marking s
11、ystem that when heatedto a molten state can be extruded or sprayed onto a road surfaceand when cooled forms a solid durable delineator or marking.4. Summary of Test Method4.1 In this test method, a weight falls through a guide tubeand impacts a striker resting on top of a supported specimen.This tes
12、t method is similar to Test Methods D5420 and D2794except the impact occurs on thermoplastic pavement markingmaterial applied over a solid road-type substrate with minimaldeformation.4.2 The test result is typically pass/fail, however maximumimpact to cause material failure can be determined as show
13、n bycracking, chipping, delaminating, etc.1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.44 on Traffic Coatings.Current edition approved Dec. 1, 2017. Published April 2018
14、. DOI: 10.1520/D8161-17.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Bar
15、r Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recomm
16、endations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.15. Significance and Use5.1 The significance of this test is to determine the thermo-plastic pavement marking materials resistance to impact overa simulated pavement substrate, under laboratory conditions,an
17、d is expressed as pass/fail or numerically. The test result canbe used as a quality test or to differentiate marking materials.5.2 Anyone attempting to perform this test should initiallyreview Test Methods D5420 and D2794, specifically theequipment setup.5.3 Sample preparation and equipment set-up s
18、hould befollowed precisely to minimize variability in the test result.6. Interferences6.1 Falling-weight-impact test results are dependent on thegeometry of the falling weight, striker, and the support. Thus,use impact tests only to obtain relative rankings of materials.Impact values cannot be consi
19、dered absolute unless the geom-etry of the test equipment and specimen conform to the end-userequirement. Data obtained with different geometries, cannot,in general, be compared directly with each other6.2 Since this method is based on the impact of a materialon a non-deformable substrate, the failu
20、re mode can come inmany different forms. This method may not cover the type ofdeformation seen on some type of products. In this instance, adetermination of whether an impact causes a passing or afailing deformation will then need to be determined by thebuyer and the seller.6.3 Impact properties of
21、thermoplastic pavement markingmaterials can be very sensitive to temperature. This test can becarried out at any reasonable temperature and humidity, thusrepresenting actual-use environments. However, this testmethod as written is intended primarily for rating materialsunder specific impact conditio
22、ns and at 75 6 2F (24 6 1C).6.4 It is possible that the apparatus used in this test methodwill not have sufficient energy available to cause failure ofsome specimens under the conditions of this procedure.7. Apparatus7.1 The basics of the apparatus are shown in Fig. 1 minusthe specimen support plate
23、 and support anvil. More detailedinformation can be found in the Apparatus section of TestMethods D5420 and D2794.7.1.1 The difference being that the test sample on the roadsubstrate is placed under the striker, and on the base of theapparatus instead of on the specimen support anvil as shown inFig.
24、 2.7.2 Although there are many sizes and shapes of strikers forthis method, we are recommending that only a 0.625 6 0.004in. (15.86 6 0.10 mm) striker be used.7.3 Although many weight loads can be used,a2lb(0.9 kg)weight is the most common and will be the only type addressedwithin this method.8. Rea
25、gents and Materials8.1 Four (4) in. Wide Drawdown Bar, capable of drawingdown a 0.125 in. thick film of thermoplastic pavement mark-ing. Other width drawdown bars and drawdown gaps can beused but this is the most common for the thermoplasticpavement marking industry (Fig. 3).8.2 Concrete Brick, with
26、 a minimum of 3000 psi compres-sion strength or substrate of choice.8.3 Asphalt Samples, cored from a road surface or made toa specific formulation and compressed in a Marshall testingdevice, then sawed in half. The top half of these types ofFIG. 1 Impact TesterFIG. 2 Specimen Support AnvilD8161 172
27、samples can be used to simulate fresh asphalt and the cut sideworn or aged asphalt surfaces (Fig. 4).8.4 Any other type of road surface or road surface coveredwith an overlay or road marking can be used.9. Hazards9.1 Impact testing of any type can cause flying debris, sosafety glasses, at a minimum,
28、 should be worn at all times.Hands are best kept away from the falling weight and impactzone. The testing device and substrate should be on a stablelevel surface at all times.10. Sampling, Test Specimens, and Test Units10.1 Sampling thermoplastic road marking material shouldbe performed by following
29、 Practice D7307.10.2 The initial melting of the thermoplastic pavementmarking materials should be performed in accordance withPractice D7308.10.3 Once the thermoplastic pavement marking material hasreached the appropriate processing temperature, then it can bedrawn over the substrate using a warmed
30、drawdown bar (Fig.5).11. Preparation of Apparatus11.1 In order to minimize the energy absorption, compres-sion and deflection of the support, affix the tester to a dense,solid block. Place this block or base at a height suitable for easeof operation. It is not necessary to bolt blocks or bases over4
31、00 lb to the floor. Alternatively, affix testers directly to thefloor. (WarningUse of rubber mats either directly under thetester or supporting apparatus is prohibited.)11.2 Bolt supporting bases, or tables, lighter than 400 lb to aconcrete floor. For each different material tested, make com-parison
32、s between mean failure energy data generated using thissupport, and one where the tester is fixed directly to theconcrete floor. If mean failure energy differences between twotypes of supports are found to be statistically non-significant,use of the lighter support shall be allowed.12. Calibration a
33、nd Standardization12.1 The striker diameter and striking end should bechecked periodically to make sure that they have not changedor been damaged from impacts.12.2 The loads weight and strike diameter should bechecked to verify that it is within tolerances.13. Conditioning13.1 Any thermoplastic pave
34、ment marking material appliedto a substrate, substrate and impact device should be allowed tocome to 75 6 2F (24 6 1C) and 30 to 50 % RH beforetesting.13.1.1 If a different temperature/humidity is required fortesting, then that temperature/humidity should be stable for thetest material, the substrat
35、e and the impact device before testing.13.1.2 Some manufacturers may require that the test mate-rial not be tested for 24 h or longer after sample prep.14. Procedure14.1 Method A Pass/Fail Testing(where the load israised to the same height for each impact).14.1.1 Install the striker having the head
36、diameter specifiedor agreed upon (Fig. 6).14.2 Place the test sample in the apparatus with the thermo-plastic pavement marking coated side facing up. Stabilize andlevel the thermoplastic pavement marking materials coatedsubstrate directly under the striker. The highway substrateFIG. 3 Drawdown BarFI
37、G. 4 Asphalt SamplesFIG. 5 Warmed Drawdown BarD8161 173should be flat against the base support and the striker in contactwith the top surface of the thermoplastic pavement markingmaterial.14.2.1 Lightly place the weight on the striker and adjust theguide tube so that the lifting pin is at the zero m
38、ark.14.2.2 Using the striker handle raise the striker to the agreedupon height.14.2.3 Release the weight so that it drops on the striker.14.2.4 After impact, catch the striker handle (if possible) inorder to prevent more damage to the impact zone.14.2.5 Remove the test substrate from the apparatus a
39、ndobserve the impact area for cracks.14.2.6 Repeat the procedure at least five times on fiveseparate test samples at the same height, drop weight andstriker.14.2.6.1 Impacts are not to land within 1.5 in. of the edge ofthe drawdown.14.3 Method B Failure Height Impact(the height atwhich the agreed up
40、on type failure occurs).14.3.1 Install the striker having the head diameter specifiedor agreed upon.14.3.2 Place the test sample in the apparatus with thethermoplastic pavement marking coated side facing up. Thehighway substrate should be flat against the base support andthe striker in contact with
41、the top surface of the thermoplasticpavement marking material.14.3.3 Lightly place the weight on the striker and adjust theguide tube so that the lifting pin is at the zero mark.14.3.4 Raise the weight up the tube to a height where it isexpected that no failure will occur. Release the weight so that
42、it drops on the striker.14.3.5 Remove the test substrate from the apparatus andobserve the impact area for cracks. If no cracks are evident,repeat the procedure at a greater height, increasing 1 in. (25mm) at a time.14.3.6 Once visible cracks are observed, repeat the test twotimes at each of three h
43、eights; slightly above, slightly belowand at that determined in the first trial.14.3.7 Record the drop height and load.14.3.8 Examine the impacted areas for cracking by one ofthe following methods:14.3.8.1 Evaluate with the naked eye.14.3.8.2 Use a magnifier to examine the area for cracks.14.3.8.3 R
44、ub a water-based dark-colored marker into thedamaged area to highlight the cracks.14.3.9 Then observe at the inch-pound (kilogram-meter)level where the coating passed or failed. The value where theresults change from mainly passing to mainly failing is theimpact failure end point.15. Calculation and
45、 Interpretation of Results15.1 Impact energy is calculated as the height the load israised times the weight of the load:IE 5 HL3 LWwhere:IE = impact energy, inch-lbsf or Joules,HL= height load drops, in. or mm, andLW= weight of load, lb or kg.15.2 Evaluation of whether the thermoplastic pavementmark
46、ing materials is a failure or not can be agreed upon by thebuyer and the seller. If no other criteria can be agreed upon, thefollowing types of failure can occur and be considered afailure.15.2.1 Crackscracks radiating from the impact zone andlonger than 0.4 in. (10 mm), visible (Fig. 7).15.2.2 Dela
47、minationsections of the thermoplastic pave-ment marking material are removed from the substrate duringimpact (Fig. 8).NOTE 1Due to this type of failure, it may not be possible to ascertainthe resistance of the material to cracking from impact. Failure bydelamination indicates a potential bond streng
48、th issue and should beinvestigated in accordance with Test Method D4796.15.2.3 Other modes of failure which had been agreed upon.FIG. 6 Striker/Specimen ApparatusD8161 17416. Report16.1 Report the following for each thermoplastic pavementmarking tested:16.1.1 Procedure A Failure or non-failure at th
49、e chosenheight,16.1.2 Procedure B The highest inch-pounds (kilogram-meters) at failure,16.1.3 Diameter of the punch used,16.1.4 Thickness of thermoplastic pavement marking mate-rial applied,16.1.5 Method of substrate preparation,16.1.6 Substrate thickness and type, and16.1.7 Atmospheric conditions under which the markingwas applied.17. Keywords17.1 chipping failure; delamination failure; impact energy;impact failure; indentation; road marking thermoplastic; strikercracking failureFIG. 7 Example of Cracks Longer than 0.4 in. (10 mm)FIG. 8 Example of Delaminat
