Report No. CDOH-DTD-R-90-4 PAVEMENT MARKING MATERIALS Richard G. Griffin Colorado Department of Highways 420 1 East Arkansas Avenue Denver, Colorado 80222 F in a I Report July 1990 Prepared in cooperation with the U.S. Department of Transportation Federal Highway Administration The contents of this report reflect the views of the author who is responsible for the facts and the accuracy of the data presented herein. The contents do not necessarily reflect the official views of the Colorado Department of Highways or the Federal Highway Administration. This report does not constitute a standard. specification. or regulation. i Technical keport Documentation Page 1. Report No. 2. Goy.rnment Accession No. 3. Recipient'. Catalog No. COOH-~R-90-4 4. Tit!e and Subtitle S. Report Date Pavement MarkL"'lg Materials 6. Perfarming Organization Code 1529A(90.11J I-:::---~---,--:--______________________--! S. Performing Orgoni zotion Report No. 7. Author's) R; r.h;nTl G. Griffin CL'OH-DID-R-90-4 9. Performinll Organization Nome and Address 10 . Worle Unit No. (TRAIS) Colorado Department of Highways Division of Transportation Development 11 . Contract or Grant No. 4201 East Arkansas Avenue Denver, CO 80222 13. Type of Report and Period Covered- ~~~~~~~~~~~------12. Sponsoring Agency Nome and Address ----------------------~ Colorado Department -of Highways Final Report 4201 East Arkansas Avenue Denver, CO 80222 14 . Sponsorinll Agency Code 1 S. Supplementary Notes Prepared in Cooperation with the U. S. Department of Transportation, Federal Highway Administration 16. Abstract '!his is a final report for a study to review and evaluate the perfonrance of pavement marking in Colorado. '!he report covers the perfonnance of materials installed transverse to the road and panel review of several long-line striping projects with higher-type pavement marking. '!he transverse test deck included mnnerous brands of both pe:rmanent and removable grades of preforined plastic, extnIded the:nnoplastic, epoxy paint, staOOard alkyd traffic paint, and .fast dry alkyd traffic paint. 'lhese materials were applied on both asphalt and concrete. Conclusions in this report are: 1. 100% solids epoxy paint is a durable marking material which outlasts numerous applications of standanl alkyd traffic paint both on asphalt and concrete. 2. catalyzed polyester paint seems to be unsuitable for the severe envirornnent of Colorado Mountain interstate highways. 3. Extruded thennoplastic is a durable marking material, maintaining its retroreflectivity throughout its life when applied to asphalt. On the test deck on asphalt, -the extnIded thennoplastic I s perfonnance was equivalent to that of the better prefonned plastics. When applied to concrete, however, extruded thennoplastic breaks up and debonds quickly. Implementation Epoxy paint is now used statewide on rural interstate l ane lines. '!hennoplastic is not recannnended on concrete pavement. 17. KeyWords 18. Distribution Statement Retroreflectivity, Mirolux, Alkyd Paint No Restrictions: Epoxy Paint, Polyester Paint, Preformed '!his report is available to the public Plastic, Extruded 'lhermoplastic through the National Infonnation service, Springfield, Vil:ginia 22161 19. Security Classi!. Cof this report) 20. Security Clossi!. (of this page) 21. No. of Page. 22. Price Unclassified Unclassified Form DOT F 1700.7 (8_72) Reproduetion of completed page authorized ii ACKNOWLEDGMENT The author is most grateful to the following panel members for their review of the pavement markings in the field, and the review and input they had to this report. Johan Bemelen staff Traffic Engineer colorado Department of Highways Robert LaForce Chemical and Bituminous Engineer Colorado Department of Highways Maurice Mitchell Assistant Engineering Coordinator Federal Highway Administration Colorado Division iii TABLE OF CONTENTS I. Introduction .................................... -. .. 1 II. Background ... 3 III. Panel Review •••••.. 9 IV. Transverse Pavement Marking Test Site ...........•... 25 V. Future Direction for Pavement Marking Research ...... 44 VI. Conclus ion .......................................... 47 VII. Implementation ...................................... 49 Figures ............................................. 53 Photos .............................................. 85 Appendix A Epoxy Paint Spec •••••••••.••...•••••••• A-l Appendix B Retroreflectometer Correlation •.•••.... B-l iv I. INTRODUCTION Pavement markings are exposed to severe punishment in many areas of Colorado. Heavy traffic, hard granite and silica based abrasives, and snow plowing down to the bare pavement place tmUSUal.ly high demands on pavement markings. Because of these severe conditions, even the use of the best marking materials means less than desirable delineation during some times of the year. Conversely, on some roadways in the state, the traffic volmne is so lOW" that the most basic and economical marking materials will serve adequately for several years. With the lcu:ge variety of pavement marking material available today and the broad range of conditions to which they can be exposed, engineers are constantly struggling with selecting the most cost-effective material for a particular location. The selection of the most cost-effective material is further corrplicated by the fact that even when traffic, envirornnent, and winter maintenance is constant for a stretch of highway, the same pavement marking seems to perfonn better in some areas than in others. Almost every roadway has certain areas which receive nore wear, nore plowing, or nore sand than the section 1/2 mile d",oJl1 the road. Pavement marking on high spots, in the middle of tun1s, and in shaded areas tends to experience more damage and wear. Consequently, a pavement marking research program was established. The objectives of this program are: 1. To determine the most suitable, cost-effective pavement marking material for Colorado I s streets and highways. 2. To establish a Colorado construction standard to provide design and maintenance personnel with a guide for selecting the pavement marking material to be used on any new construction, overlay, or restriping job. 3. To provide a continuous evaluation program that will accept new materials to be evaluated against material currently in use so that the use of iInproved striping material can be quickly assimilated into Colorado standards. This report dc::cuments the installation and evaluation of a pavement marking transverse test section, established to systematically evaluate various pavement marking materials, and the pavement marking panel review of numerous long-line proj ects. 2 II. BACKGROUND various pavement mar1d.nJ systems are being evaluated in the pavement marking researd1 program. A discussion of each type is included here as background for the reader. Further, it is also inp:>rtant that the reader understand the tem. "retroreflectivity" and the instnnnents used to measure it; therefore, a discussion on this subject is included. Arrl, finally, discussion on the glass beads, which provide the retroreflectivity, is included. A. PAVEMENT MARKING MATERIAL SYSTEMS 1. Epoxy Paint '!he prilnary change in the pavement marking program in Colorado in recent years has been the use of 100% solids epoxy paint. '!his ma.terial is a two-part chemistry based on two parts of eIX>XY resin to one part epoxy hardener. 'Ihe materials are mixed in a chamber just before they are sprayed onto the pavement followed by glass beads distributed by pressurized air. '!he epoxy is heated to 80 - 140 degrees Fahrenheit to inprove flow and mixing and to accelerate the curing rate. '!he ma.terial is applied at 15 mils (15/1000 inches) with beads being blown on at the rate of 25 pounds per gallon or 0.20 pounds per square foot. Dry t:bne depends on temperature and htnnidity but is typically 40 minutes to complete cure. Since this ma.terial is a 100% solid formulation there is practically no VOC (volatile organic c::anp:mnd) emissions, and the wet thickness is equivalent to the dry thickness. See Appendix A for Colorado's latest specification. '!his eIX>XY formulation has been used successfully in other states including: Illinois, Wisconsin, Kentucky, Ohio, IOINa, New Mexico, Arizona, and Utah. Agent and Pigman1 (1984) fourxl the epoxy still had good retroreflectivity after two years of service but the gray-white appearance created a daytime contrast problem on concrete. H. Gillis of the Minnesota ror indicated that the eIX>XY lasted over one year on a high-traffic roadway where conventional paint would only last three months (Ma;rath2). 3 2 . Preformed Plastic 'Ihe use of preformed plastic has also increased in Colorado for both short tenn and pennanent pavement marking. Pennanent markings have been installed on new asphalt by layi.n;J the material in place just before the final pass of the compaction roller. Material installed by this process is referred to as inlaid preformed plastic, because it ends up partially embedded in the surface of the pavement. CIXlH has experienced gocx:i perfonnance with these inlaid preformed marking materials. '!hey remain over 90% intact and in place after several years of service on freeways with over 100,000 vehicles per day. Performance has varied, somewhat, between different brands of preformed material. Re,'l,ovable grades of preformed marking materials are also being employed through constru.ction projects where detour or short-term markings on the final roadway surface are necessary. '!his allows removal of these short-tenn