1、Designation: D 4796 88 (Reapproved 2004)Standard Test Method forBond Strength of Thermoplastic Traffic Marking Materials1This standard is issued under the fixed designation D 4796; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, th
2、e year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method provides an instrumental means for thedetermination of thermoplastic traffic marking mater
3、ial bondstrengths using cement bricks and steel cubes.1.2 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is therespon
4、sibility 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:2C 109/C 109M Test Method for Compressive Strength ofHydraulic Cement Mortars (Using 2-in. or
5、50-mm CubeSpecimens)C 881/C 881M Specification for Epoxy-Resin-Base Bond-ing Systems for ConcreteD 883 Terminology Relating to PlasticsE 284 Terminology of AppearanceF 412 Terminology Relating to Plastic Piping Systems3. Terminology3.1 DefinitionsDefinitions are in accordance with Termi-nology D 883
6、, E 284, and F 412 unless otherwise indicated.3.2 Definitions of Terms Specific to This Standard:3.2.1 cement brick, na brick formed by mixing cementand fine sand together and allowing to harden.3.2.2 thermoplastic, ntraffic marking (same as 3.2.3).3.2.3 thermoplastic traffc marking, na highly fille
7、d100 % total solids highway marking system that when heatedto a molten state can be extruded or sprayed onto a road surfaceand when cooled forms a solid durable delineator.4. Summary of Test Method4.1 The thermoplastic specimen is prepared for this test byfirst melting a sample to its application te
8、mperature undercontinuous agitation. The specimen is then applied to thespecified cement brick by a hot drawdown blade. Two steelcubes are then immediately placed onto the hot thermoplasticline and the excess thermoplastic trimmed away from aroundthe two steel cubes. After the trimming is complete,
9、the steelcubes are removed. A heated steel cube is bonded with epoxyto the square of thermoplastic and allowed to cure overnightbefore determining the bond strength on a Dillon dynamometeror similar device.5. Significance and Use5.1 The function of this test method is to provide numericalinstrumenta
10、l results indicating the cohesive or adhesive, orboth, bond strength of thermoplastic traffic marking to aspecified cement brick substrate.5.2 The use of this test method allows the user and manu-facturer to control the quality of the product and makeinferences about the performance of the thermopla
11、stic trafficmarking product. Results from these tests also provide infor-mation helpful in researching and developing thermoplastictraffic marking materials.5.3 Strict adherence to the procedures outlined is necessaryfor precision of the test method. Under no conditions shouldthe bond strength be ac
12、cepted unless there is conformance to9.14. Precise results are obtained only when one steel block isepoxied to the thermoplastic traffic marking on the cementbrick.6. Types of Separation in Bond Strength Tests6.1 Thermoplastic to Steel Cube SeparationThis type ofseparation occurs where there is an i
13、nsufficient bond betweenthe thermoplastic and steel cube probably due to insufficientcoverage of the epoxy adhesive.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 Tr
14、affic Coatings.Current edition approved June 1, 2004. Published June 2004. Originallyapproved in 1988. Last previous edition approved in 1998 as D 4796 88 (1998).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book
15、of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.2 Thermoplastic to Thermoplastic SeparationThis typeof separation is caused by int
16、ernal cohesive failure of thethermoplastic. This separation is acceptable when it exceedsthe specified bond strength.6.3 Thermoplastic to Cement Brick SeparationThis typeof separation is caused by the failure of the bond between thethermoplastic specimen and the cement brick.6.4 Cement Brick to Ceme
17、nt BrickThis type of separationis caused by the internal cohesive failure of the brick. This isdue, in most cases, to a bond between the thermoplastic andcement brick that exceeds the cohesive strength of the cementbrick. This separation is not acceptable when the bond strengthvalues are lower than
18、specified.7. Apparatus7.1 Agitator Blade, 150 mm (6 in.) long with a 10 mm(12-in.) steel shaft and a 45 by 25 by 3 mm (134 by 1 in. by18-in.) straight horizontal steel blade.7.2 Capped Bolts, two, 16 mm (58 in.) in size.7.3 Cement Bricks,9by5by19cm(312 by2by712-in.) insize with a compressive strengt
19、h of 3000 to 5000 psi (Note 1).NOTE 1Concrete bricks conforming to Test Method C 109/C 109Mhave been used but proved more variable due to migration of a thin veneerof cement to the top of the brick making determinations erratic. Thecement bricks may be obtained from local block plants. The term“ceme
20、nt” brick is common for the industry and is used in this test methodextensively.NOTE 2The unit should be fitted with a steel frame to hold the cementbrick for testing.7.4 Dynamometer,3with a capacity of 6000 lbs in 2700 kgin 10 kg (25-lb) divisions having a pull-rate capability of14in./min. (6 mm/mi
21、n) (Note 2) (See Fig. 1, Fig. 2, Fig. 3, andFig. 4).7.5 Draw Down Blade, 5 by 2.5 by 10 cm (2 by 1 by 4 in.)in size capable of laying down a 125 mil (0.125 in.) wetthermoplastic film 2-in. wide.7.6 Drill Press, or other apparatus capable of agitating thethermoplastic during meltdown to the applicati
22、on temperatureat 600 to 800 r/min in the jacketed electric pots.3The sole source of supply of a Dillon Dynamometer known to the committeeat this time is WeighTranex, 1000 Armstrong Drive, P.O. Box 1000, Fairmount,MN 56031. If you are aware of alternative suppliers, please provide this informationto
23、ASTM International Headquarters. Your comments will receive careful consid-eration at a meeting of the responsible technical committee,1which you may attend.FIG. 1 Bond Strength Testing ApparatusFIG. 2 Tension BedFIG. 3 Load Plate (2 Required)D 4796 88 (2004)27.7 Epoxy Resin and Hardener, Type I or
24、II, Grade 2, ClassC in accordance with Specification C 881/C 881M.7.8 Hot Plate, capable of maintaining 537C.7.9 Gravity Convection Oven, capable of maintaining260C.7.10 Electric Pots, Jacketed, for heating and melting thethermoplastic to 218C.7.11 Spatulas, for cutting, stirring, and shaping the th
25、ermo-plastic.7.12 Steel Cubes, two, 50 by 50 by 50 mm (2 by 2 by 2 in.)in size threaded in the center of one side for a 16-mm (58-in.)capped bolt.8. Sampling8.1 Samples may be obtained by an appropriate quarteringor riffle sampling method where deemed necessary consideringthe physical form of the ma
26、terial.9. Procedure9.1 Under continuous agitation melt a specimen of thethermoplastic to be tested to a temperature of 218C. If thespecimen is a dry powder mix, allow the specimen to cool to193C under continuous agitation and reheat under agitation to218C.NOTE 3Dry powder mixed thermoplastic must be
27、 conditioned toensure a homogeneous melt necessary for consistent results. Premeltedblock thermoplastic does not require this conditioning. The specimen maybe melted on a hot plate set at 537C or in a jacketed electric pot.Continuous agitation is necessary to prevent scorching and settling. If thesp
28、ecimen is melted in an oven set at 260C, the specimen must be agitatedevery 15 min until 218C is reached.9.2 Heat the draw down blade to 218C.9.3 Obtain a dry room temperature cement brick that hasbeen brushed or textured on the side to be coated withthermoplastic.9.4 Heat one 50 by 50 by 50 mm (2 b
29、y 2 by 2 in.) steel cubein an oven or on a hot plate to 49C for 2 h prior to making thethermoplastic draw down on the cement brick.9.5 When the thermoplastic specimen is melted to 218Cunder continuous agitation, remove the agitator blade from thethermoplastic.9.6 Remove the draw down blade from the
30、hot plate andimmediately place it on the cement brick and make the drawdown the full length of the brick with the melted thermoplasticon the brushed or rough textured side of the brick.9.7 Immediately place two room temperature steel cubes onthe thermoplastic approximately 25 mm (1 in.) from each en
31、dof the brick and trim the plastic from around the two steelcubes before the plastic cools and hardens.9.8 Remove the steel cubes by hand and allow the thermo-plastic to cool for 1 h.9.9 Prepare the epoxy solution using the proper resin andhardener ratio and mix thoroughly.9.10 Remove the steel cube
32、 heated to 49C from the ovenand place a small amount of epoxy on the heated cube. Placethe steel cube on the thermoplastic square and rub to ensure aneven coating and good adhesion. To ensure an even coating,remove the steel cube from the thermoplastic square andvisually inspect the square and cube
33、and then replace the steelcube on the square and rub. Do not allow any excess expoxysolution to flow from the steel cube and thermoplastic squareonto the cement brick.NOTE 4Only one steel cube can be epoxied at a time to thethermoplastic on the brick because the shock of the first pull will cause ap
34、remature release of the second thermoplastic square.9.11 Place a weight such as a cement brick on the steel cubeepoxied to the thermoplastic square and allow to cure for aminimum time of 8 h.9.12 Screw the 15.9-mm (58-in.) capped bolt into the steelcube epoxied to the thermoplastic and place the bri
35、ck into thesteel frame mounted onto the dynamometer.9.13 Set the dynamometer to zero and pull the steel cube at6 mm/min (14 in./min).9.14 Two tests are run on each brick. Separations involvingat least 80 % of the thermoplastic area to the cement brick,thermoplastic to thermoplastic, and cement brick
36、 to cementbrick are acceptable for reporting bond strengths.10. Calculations10.1 Calculate the bond strength as follows:10.1.1 Average the readings obtained in 9.13 if the condi-tions in 9.14 are met.10.1.2 Divide the average reading obtained by 4. The resultis the bond strength in pounds per square
37、 inch.10.1.3 If one of the two tests fails then that test is repeateduntil the conditions of 9.14 are met.11. Report11.1 Report the following information:11.1.1 The type of separation and bond strength, the batchnumber, color, and type of thermoplastic.11.1.2 The determination of the area of separat
38、ion is sub-jective. The area not involved in the separation is usuallyattached to the steel cube or cement brick.FIG. 4 Coupling HitchD 4796 88 (2004)312. Precision and Bias12.1 PrecisionNo general statement of precision can bemade because of lack of sufficient data at this time.12.2 BiasNo statemen
39、t of bias can be prepared for thistest method since there is no absolute method for use as acomparative basis.12.3 Experience dictates that test results with 650 psi areacceptable.13. Keywords13.1 bond strength; cement brick; thermoplastictrafficmarkingASTM International takes no position respecting
40、 the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standar
41、d is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International
42、 Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.Thi
43、s standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).D 4796 88 (2004)4
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