Highway $ Tmansportation Reseamch Council. opinions, findings, and conclusions expressed in this

Transcription

1 D. Shepard F. Scientist Research opinions, findings, and conclusions expressed in this (The are those of the authom and not necessarily those of mepomt Highway $ Tmansportation Reseamch Council Virginia Omganization Sponsomed Jointly by the Vimginia Cooperative of Highways g TransportaZion and Depamtmenr Univemsiry of Vimginia) the 1980 August 81-R7 VHTRC COMPARISON OF HIGHWAY STRIPING MATERIALS by the sponsoring agencies.) (A Cham!otZesvil!e, Virginia

2 H. E. PATTERSON, Senior Traffic Engineer, Norfolk Department MR. Public Works of TRAFFIC RESEARCH ADVISORY COMMITTEE MR. L. C. TAYLOR II, Chairman, District Traffic Engineer, VDHgT MR. L. H. DAWSON, JR., Assist. Traffic $ Safety Engineer, VDH$T MR. J. B. DIAMOND, District Traffic Engineer, VDHST MR. J. E. GALLOWAY, JR., Assist. State Materials Engineer, VDHgT DR. JAMIE HURLEY, Assist. Professor of Civil Engineering, VPI $ SU MR. C. 0. LEIGH, Maintenance Engineer, VDHgT MR. R. F. MCCARTY, Safety Coordinator, FHWA MR. J. P. MILLS, JR., Traffic $ Safety Engineer, VDHST MR. W. C. NELSON, JR., Assist. Traffic $ Safety Engineer, VDH$T MR. R. L. PERRY, Assist. Transp. Planning Engineer, VDH$T MR. F. D. SHEPARD, Highway Research Scientist, VHgTRC ii

3 study was undertaken to investigate problems relating This the durability of pavement striping materials used by the to The research was limited to an evaluation of the Department. and retroreflectance characteristics of selected paints, durability and prefommed tapes recommended by the Materials thermoplastics, for use as centerline and edgeline striping. The report Division that the state adopt a performance specification wherein tion would be required to submit their traffic paints for on- suppliers evaluation and the product exhibiting the best overall the-road considering general appearance, durability, night performance, SUMMARY the installation procedure and presents the results of the details of the selected materials. Included is a recommenda- evaluation visibility, and cost, would be purchased. iii

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5 D. She pard F. Scientist Research a result of a discussion of various problems relating to As durability of the traffic paint used by the Department at the the Upon meeting, the task force recommended that field tests lems. selected traffic striping materials be initiated. Also, it was of that an investigation should be made into questions con- thought paint specifications, drying times, and performance versus cerning specifications. At subsequent meetings of the task force, materials was established that the Materials Division would select the it to be tested and the Research Council would perform the materials and prepare a final report. evaluation state has used various highway striping materials with The degrees of success; however, at no time have all the varying materials been applied at the same time and place for com- various The primary purpose of this study was to field test traf- parisons. striping paints to investigate questions concerning the overall fic with emphasis on durability, appearance, and night visi- performance As an afterthought it was decided to include various thermo- bility. formulations and preformed tapes to compare categories of plastic study was limited to the testing of those highway striping The recommended by the Materials Division as used for center- materials and edge!ine striping. The materials were applied at one loca- line on bituminous pavement and one on concrete pavement. tion COMPARISON OF HIGHWAY STRIPING MATERIALS by INTRODUCTION 31, 1978, meeting of the Traffic Research Advisory Committee, May was recommended that a task force be formed to study the prob- it PURPOSE Also, it was hoped that the investigation would provide materials. basis for evaluating the Department's specifications for the com- a and purchasing of such materials and lead to improvements position warranted. if SCOPE

6 site chosen for placement of the materials was on Inter- The 95 southbound, just south of the Route 301 exit in Richmond. state pavement in this area transitions from concrete to bituminous The thereby allowed placement of materials on both surface types and almost identical traffic conditions. This site has an under annual daily traffic of approximately 25,000 vehicles. average A-702" Virginia's conventional white. A i. conventional paint with a soya-tung oil minute TM-5368: New Jersey's type IV 2. A cold applied paint. white. TM-9216" Virginia's fast-drying white (thick). 4. as #3, but with double thickness. Same High durability two-minute dry white. 6. as #3, but with 2-minute drying time. Same TM Virginia's fast-drying yellow (thick). 8. as #?, but with double thickness. Same PROCEDURE Site n el. Marking Materi...a s Selec..t...i by the Materials Divison and subsequent con- Recommendations by the task force led to the selection of 14 traffic sideration 6 thermoplastics, and 7 tapes. A list of these materials paints, in the order they are placed on the road is given below. Traffic Paints vehicle. chlorinated rubber TM-9216 Virginia' s 3. drying time fast-drying white. Has a and linseed oil vehicle. 50-second " Virginia's fast-drying white. Has 5. oil rather than linseed oil in the alkyd. soya TM-9217 Virginia' s fast-drying yellow. Same 7. #3, but in yellow. as " Virginia's fast-drying yellow. Same 9. #5, but in yellow. as

7 High durability two-minute dry yellow " as #6, but in yellow. Same Virginia's conventional yellow. A-701" but in yellow. #I, TM-5367" yellow. Jersey's type IV chlorinated rubber New as #2, but in yellow. Same Fast dry waterborne white " in white. but Thermopl_ stics. 2-component hard resin and color Yellow conforming to the current Virginia 9HM31- specifications. High performance white. 9HM33" thermoplastic. performance Lower cost white. 9HM30: specification. Polamide experimental. Differ ent resin 9PLM35 as thick. "Between a paint and a thermoplastic." not Federal Highway Administration's epoxy 9HM34" A 2-component epoxy. Is precatalized, thermoplastic. Also, it is basically the same type material roads. that applied around Williamsburg. as Same as Water emulsion Fast dry waterborne yellow " latex acrylic. or Same as #13, 9HM3 2 Same as #15, but in white. Supposedly a high Lower than Virginia pre-coated and only when heat is applied do the i.e.,.mix and react. It can be applied to damp components 257 3M Durable tape, yellow. 5361" 3M Scotchlane tape, yellow. 5731" 3M Sta-Mark tape, yellow. 5730" 3M S ta-mark tape, white.

8 of the variety of materials selected for test, coupled Because the desired location, the uniform and controlled application with the materials presented a problem, especially if state forces of to be used. However, it was learned that the Baltimore Paint were for the desired paint coverage, paint film thickness equipment 16 mils, wet) and glass bead coverage is shown in (approximately 2 and 3. After calibration of the equipment, paint stripes Figures applied to the pavement as shown in Figures 4 and 5. Figure 6 were shown in Figure 9, two lines 12 inches apart were applied As each type material. Figures i0 and Ii show the test stripes for on concrete and bituminous pavements, respectively. Close- placed of the lines are shown in Figures 12 and 13. ups 2, 1979, by members of the Research Council and Materials Divi- ber personnel. The characteristics evaluated were (I) general sion (2) dumability, and (8) night visibility. The general appearance, was judged by viewing the lines from the side of the appearance took into account such factors as fading, yellowing, darkening, and dirt accumulation. It was mated on a scale of 0 (complete failure) and M Durable tape, white " 3M Scotchlane tape, white " 3M Sta-Mark tape (Va.), white. Placement Chemical Company had the equipment and expertise to apply all and desired materials, and they were contracted to install all the the sections with the exception of the pavement tapes. Since the test are preformed, no special apparatus was required for their tapes It is noted that the pavement was primed prior to the placement. of the thermoplastics and preformed tapes. placement equipment used for application of the paint striping is The in Figure 1 (all figures are attached). Calibration of the shown the equipment used for placement of the thermoplastic mate- shows and Figure 7 shows the thermoplastic being applied. Figure 8 rials shows the preformed tapes being applied to the pavement. Evaluation lines weme evaluated by inspecting each line and wheel The The field observations were made pemiodically from Septem- path. to i0 (perfect).

9 durability was rated by estimating, from examination with The unaided eye, the percentage of line remaining in the wheel the These ratings were made on a scale of 0 (no line remaining) tracks. i0 (no film loss). For the ratings, ASTM designations D to resistance) and D (chipping resistance) were used (abrasion standards for comparison. Details of the rating scale are shown as Table I. The percentage of line remaining on the pavement is in as the percentage of the wheel track area in which the considered is not exposed. The term "wheel track" is defined as the pavement of greatest wear caused by the tire and the 9 inches to either area Therefore, each line has two wheel tracks approximately 18 side. wide as shown in Figure 9. inches i0 Durability Rating Scale night visibility designates the brightness of the mate- The obt.ained by utilizing photometric readings taken with a rials meter placed on each line in the wheel tracks. retroreflectance paints, the night visibility at each inspection was taken as For percentage of the original average night visibility for each a color, as measured by the photometer; i.e., the original paint of night visibility for all white paints on both concrete values bituminous pavements were averaged and individual paint values and at each inspection thereafter were presented as a percent- obtained of the original average. The same procedure was followed for age paints. Night visibility values at each inspection for the yellow and preformed tapes were taken as a percentage of thermoplastics I I Table i Percentage Scale De scr iption!n.tact_t_ ASTM.Design o perfect condition intermediate failure 77% 60% requires restriping complete failure the original brightness of each individual material. The night

10 overall rating, R : appearance rating, A durability rating, and D- night visibility rating. N failure, it is felt that sufficient data are available for the to of this evaluation. purposes overall rating for each paint stripe is shown in Table 2 The with the "days to failure", which was based on the length of along required for the overall rating to reach time value of 4.0. Also, a plotting the rating of each paint type considered versus that graphs on the results obtained from these test applications, Based were differences in the quality of paints. Using "days to there as a criterion, the white paints failure" concrete pavements show- on the highest rating were Virginia's fast drying white with linseed ing in place of soya oil (#5), and the high durability, two-minute oil paint (#6). For the yellow paint on concrete pavement, Virgin-. dry fast drying yellow (thick #8), and New Jersey's Type IV chlo- ia's rubber yellow (#12) were the best. rinated the white paints tested on bituminous pavements, Virginia's Of drying paint (thick #4); high durability, two-minute dry paint fast and Virginia's fast drying paint with linseed oil in place of (#6); oil (#5) were superior. Of the yellow paints on bituminous soya mating (N) was on a scale of 0 (no night visibility visibility to 10 (100% of initial night visibility Peading). reading) Rating (R) 0.I0 A D N, where RESULTS results are presented on the basis of the overall rating The discussed above. Although all test strips have not deteriorated as Paint Virginia's current standard paint (No. 3, white and No. 7, yellow) of shown in the Appendix. are Virginia's fast drying (thick #8) and New Jersey's Type IV pavements, rubber (#12) were the best. chlorinated

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12 the "days to failure" for both pavement types, the Averaging paints having the highest rating were Virginia's fast drying white linseed oil in place of soya oil (#5) and the high durability, with dry (#6). For the yellow paints, Virginia's fast drying two-minute #8) and New Jersey's type IV (#12) chlorinated rubber were (thick superior. applied to the concrete pavement deteriorated faster Paints those placed on the bituminous surface. With the exception of than yellow paint placed on bituminous pavement, the traffic paint the currently uses (white #3, yellow #7) had relatively low Virginia comparison of paints using soya oil instead of linseed oil A a vehicle showed that those with soya oil were superior in the as ratings for white and yellow paints on both concrete and overall pavements, with the exception of yellow on bituminous bituminous T.. er op.la.s t i c s 3 gives the overall rating for each thermoplastic placed. Table materials placed on bituminous pavement rated higher than those Those on concrete; however, the primary reason for this was the ear- placed spailing of those materials placed on the concrete pavement. Be- ly ratings.. 0il...ys, _Linseed.Oil pavement. Paint Thickness Virginia's standard paint (#3 white and #7 yellow) at Placing wet thickness of 15 mils and 26 mils resulted in higher overall a for the thicker paints. A 32% increase in the overall rat- ratings was found for white paints and a 103% increase for yellow. Also, ing is noted that a higher night visibility was maintained throughout it the observation period for the thicker paints. of this excessive spailing of thermoplastics, especially on cause it is felt that insufficient results are available to allow concrete, conclusions concerning the overall effectiveness of the thermo- any materials used. plastic

13 October 23, 1979 Class Designation 9HM HM HM HM I 5.4 Pr e formed_.tap e s overall ratings for preformed tapes are shown in Table 4. The of the tapes considered had high overall ratings without de- Most to the point of failure (R = 4.0) as of May i, teriorating high overall rating is primarily due to the durability rating The is reiterated that the night visibility factor is based on It percentage loss of night visibility relative to the initial the of preformed tapes were much brighter initially than the colors or thermoplastics, with the white tape being twice the value paints yellow. Values for the white paint and thermoplastic were about of same when the materials were applied (September 24, 1979). Also, the yellow paint was about half as bright as the white. After ap- the two months, all materials had substantailly decreased proximately night visibility, with the exception of the thermoplastics, which in about the same. The night visibility values for the tapes remained at least triple those for comparable colors in the paint cate- are however, they show a lower percentage of initial night visi- gory; Also, the tapes were still brighter after two months than bility. initial readings for paints and thermoplastics. the Table Overall Rating for Thermoplastics November 28, 1979 January 16, 1980 Conc. Bitum. Conc.-! Bitum. Conc. Bitum. 9HM HM '.0 high since the tapes are relatively intact. The night remaining rating decreased steadily for all tapes except numbers visibility 24, and 27, which increased between the January 16 and May!, 23, inspections. Graphs showing the overall rating versus time 1980, are shown in the Appendix. upon placement. Table 5 gives an example of the average visibility visibility readings for all materials in each category. Both night

14 Conc. Bi. Conc. -Bitum Conc Bitum. Conc Bitum Cost per and Foot Classification S731 2t S Q q , Average Nigh Visibility Values , ,2, S O i" '79 (}45. 28, ( Sept.- 2'4!.'..'I' Visibility 35 Tab le 4 Overall Rating for Preformed Tapes I I Table 5 Percent Initial Night Visibility CaZegomy N.,,ish Paint white yellow Paint 38 white i0.0 Themmoplastic white Tape 21 Tape yellow i0

15 The method of placing transverse lines across the pavement I. the purpose of determining the performance of marking for has merit. It should be noted that the time materials for sufficient deterioration to determine their required was considerably longer for preformed tapes and performance than for paints. thermoplastics The white paint exhibiting the highest overall rating was 2. fast drying (50 second) paint that has soya oil Virginia's Paints using soya oil in place of linseed oil as a vehicle 3. exhibited higher overall ratings. generally compamison of paint thicknesses showed higher ovemall A for thicker paints (2 mils wet vs. 15 mils wet). ratings Paints applied to the concrete pavement deteriorated faster 5. those placed on bituminous pavement. than results were available to allow conclusions Insufficient the performance of the thermoplastic materials. concerning Most of the preformed tapes were still intact on both pave- 7. types and exhibited acceptable overall performance. It ment that the performance of each tape is related to its seems cost. Upon initial installation, there was little difference in 8. visibility for paints and thermoplastics; however, night After two months, thermoplastics and pmefommed tapes generally 9. night visibility ratings 3 to 4 times those for comparable had Overall, it is believed that the results were very beneficial i0. learning about the. relative performance of selected paints in a controlled environment and are a major step in ensuring under the state is getting the best product for its expenditures. that CONCLUSIONS than linseed oil in the alkyd. The best yellow paint rather Virginia's fast drying (50 second) paint having a linseed was oil vehicle and placed at double thickness. preformed tapes were 5 to 8 times as bright. in the paint category. Also after two months, the tapes colors brighter than were the paints and thermoplastics when they were were initially installed. ii

16 is recommended that the state adopt a performance specifi- It wherein suppliers would be required to submit their traffic cation for on the road evaluation and the product exhibiting the paints overall performance, considering general appearance, durability, best is recommended that the Department change the Road and Bridge It Zo allow the use of soya oil as well as linseed 0il. Specifications should be given to the testing of preformed tapes Attention on the road performanc e techniques. It is noted that such an using would take considerably longer than the evaluation of traf- evaluation paints; therefore, conditions leading to a rapid deterioration fic RECOMMENDATIONS night visibility, and cost, would be purchased. should be considered. Minimum values for night visibility of traffic markings should be considered. 12

17 Figure i. Paint striping machine. Figure 2. Calibrating for paint thickness. 13

18 Figure 3. Checking test plate for paint thickness. Figure 4. Beginning of test stripe application. 14

19 Figure 5. Applying test stripe on pavement and sample plates. Figure 6. Machine for applying thermoplastic. 15

20 Figure 7. Applying thermoplastic material. Figure 8. Applying preformed tapes. 16

21 Sample No. 2 Sample No. i area wheel t aek of approximate Figure 9. Placement of test materials. Shoulder...:::::::: :)::::::::::ii?!iii!iii?ii :::::::::::::::::::::::::: Traffic flow 17

22 Figure i0. Test section on concrete pavement. Figure ii. Test section on bituminous pavement. 18

23 Figure 12. Typical test stripes. Figure 13. Close-up of test strmpe. 19

24 Figure 14. Retroreflectance meter. 2O

25 APPENDIX GRAPHS SHOWING OVERALL RATING VS. TIME FOR STRIPING MATERIALS

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27 z Z

28

29

30

31

32

33 0

34 A-IO

35 i!-- A-II

36 A-12

37 A-13

38 A-14

39 A-15

40 A-I6