irt No. FHWA/RD-80/059 no. hHWA- wu- ao-uby ALUATION OF HIGHWAY CULVERT COATING PERFORMANCE June 1980 Final Report Document is available to the public through the National Technical Information Service, Springfield, Virginia 22161 Prepared for FEDERAL HIGHWAY ADMINISTRATION Offices of Research & Development iED Structures & Applied Mechanics Di\BsW Washington, D.C. 20590 MO ^ ^ RoFHM FOREWORD This report presents the results of an evaluation study and recommends improvements in current practices and procedures on protective coatings for highway culverts. This evaluation consisted of conducting field investigations in nine States and a comprehensive literature review on the following types of coatings: asphalt, asbestos bonded asphalt, asphalt paving, coal tar laminate, polyethylene, PVC, vinyl plasticsol, aluminized, aluminum-zinc, and epoxy coated concrete. Additional coatings and methods of protection are suggested which may be superior to existing coatings, but have not been sufficiently evaluated to justify additional cost. An evaluation program is presented for potential improvement in existing culvert specifications and recommendations. This report will be of primary interest to supervisors and engineers responsible for the design, construction, and maintenance of culverts and pipes used in highway and road drainage systems. This report is being distributed under FHWA Bulletin with sufficient copies of the report to provide a minimum of three copies to each regional office, three copies to each division, and five copies to each State highway department. Direct distribution is being made to the division offices. ( *£#.*' Charles F. Sch^fey Director, Office of Research Federal Highway Administration NOTICE This document is disseminated under the sponsorship of the Department of Transportation in the interest of information exchange. The United States Government assumes no liability for its contents or use thereof. 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 or policy of the Department of Transportation. This report does not constitute a standard, specification, or regulation. The United States Government does not endorse products or manufacturers. Trademarks or manufacturers' names appear herein only because they are considered essential to the object of this document. Technical Report Documentation Page I. Report No. 2. Government Accession No. 3. Recipient's Catalog No. FHWA/RD-80/059 4. Title and Subtitle 5. Report Dare y June 19 80 EVALUATION OF HIGHWAY CULVERT COATING PERFORMANCE 6. Performing Organization Code 8. Performing Organization Report No. 7. Author's) W.T. Young 9. Performing Organization Name and Address 10. Work Un.t No. (TRAIS) PSC Professional Services Group, Inc. 3513-224 , -. Contract or Grant No. 110 Essex Avenue FEB 1J1 Narberth, PA 19072 DOT-FH-11-9425 13. Type of Report and Period Covered 12. Sponsoring Agency Name and Address Final Report Offices of Research and Development June 1978 to November 1979 Federal Highway Administration U.S Department of Transportation 14. Sponsoring Agency Code Washington, D.C. 20590 15. Supplementary Notes FHWA Contract Manager: G. W. Ring (HRS-14) The objective of this study was to evaluate the performance of coatings for highway culverts and to recommend methods of improving culvert service life through improved coating systems and other means. A literature search was conducted through a review of technical literature and interviews with cognizant state officials throughout the United States. The literature and search revealed durability problems with the most commonly used materials coatings. Corrosion and erosion of interior surfaces appear to be the most in serious durability problems in most states. Field investigations conducted nine states confirmed the findings of the literature search. Most coatings exhibit durability problems under conditions of abrasive bed load and extreme corrosivity. Coating types examined at various test sites and actual drainage installations include: asphalt, asbestos bonded asphalt, asphalt paving, coal zinc tar laminate, polyethylene, PVC, vinyl plastisol, aluminized, aluminum - asphalt coated and epoxy coated concrete. The best overall coating appears to be and paved asbestos bonded galvanized steel, although significant deterioration coatings applied is probable with this coating under certain conditions. Organic present complete to local areas where needed might be more cost effective than suggested which coating methods. Other coatings and methods of protection are methods are might be superior to existing coatings. Many of these alternative yet. more costly than existing coatings and their benefits are not defined justified. A Durability evaluations are needed to deterimine if their use is for improvement review of existing State culvert specifications and recommendations presented.pre -axur^ j nolnrlprl . An evaluation program is 17. Key Words 18. Distribution Statement Culverts Corrosion No restrictions. This document is avail- Drainage Pipe Erosion able to the public through the National Materials Technical Information Service, Springfield, Coating Virginia 22161 19. Security Classif. (of this report) 20. Security Classif. (of this page) 21- No. of Pages 22. Price Unclassified Unclassified 157 (8-72) Form DOT F 1700.7 Reproduction of completed page authorized OBJECTIVE The objective of this study was to evaluate the performance of coatings for highway culverts and to recom- mend methods of improving culvert service life through improved coating systems and other means. A literature search was con-ducted through a review of technical litera- ture and interviews with cognizant state officials through- out the United States. The literature search, revealed durability problems with the most commonly used materials and coatings. Corrosion and erosion of interior surfaces appear to be the most serious durability problems in most states. Field investigations conducted in nine states confirmed the findings of the literature search. Most coatings exhibit durability problems under conditions of abrasive bed load and extreme corrosivity. Coating types examined at various test sites and actual drainage installa- tions include: asphalt, asbestos bonded asphalt, asphalt paving, coal tar laminate, polyethylene, PVC, vinyl plasti- sol, aluminized, aluminum - zinc and epoxy coated concrete. The best overall coating appears to be asphalt coated and paved asbestos bonded galvanized steel, although significant deterioration is probable with this coating under certain conditions. Other coatings and methods of protection are suggested which might be superior to existing coatings. Many of these alternative methods are more costly than existing coatings and their benefits are not defined yet. Durability evaluations are needed to determine if their use is justified. A review of existing state culvert specifica- tions and recommendations for improvement are included. An evaluation program is presented. PREFACE This study is part of a continuing effort to improve the performance of highway culverts, and in doing so, lower the cost of highway maintenance. We wish to thank all of those individuals in the various State highway departments for their cooperation in giving the experiences of their States with regard to culvert performance and for supplying specifications and technical data. The cooperation and assistance of those States in which we performed the field inspections is most appreciated. We also thank those coating fabricators and coating suppliers that we contacted for their cooperation. 11 TABLE OF CONTENTS PAGE SUMMARY 1 INTRODUCTION 3 DISCUSSION 5 Literature Review 5 Field Investigation 7 Procedures 7 Results, General 10 Results, Individual Coating Types 14 Asphalt 14 Asphalt Coated Aluminum 17 Asbestos Bonded Asphalt Coated 17 Coal Tar Laminate 18 Polyethylene 20 Polyvinyl Chloride 20 Epoxy Coated Concrete 21 Others 21 Coating Test Sites 23 Asphalt Coating Performance 24 Coating Need and Alternative Means of Protection 29 Alternative Coatings 32 Galvanizing 35 Specification Review 37 CONCLUSIONS 39 RECOMMENDATIONS 41 FIGURES 1-42 42 TABLES I-XI 66 APPENDIX A - Corrosion and Erosion Effects on Culverts 103 APPENDIX B - Literature Review Summary 106 APPENDIX C - References 135 iii PAGE APPENDIX D - Corrugated Steel Pipe Fabricators 143 Interviewed and Visited, Asphalt Refiners Interviewed APPENDIX E - Suggested Culvert Coating Specification 145 APPENDIX F - Recommended Test Program 150 IV List of Tables Table Title Page I Literature Review Results 66 II Summary of Culverts Inspected 67 III Culvert Test Sites - Description and 68 Location IV Summary of Field Test Data 79 V Typical Culvert Asphalt Specification Limits 92 VI Variation in Asphalt Composition Within AASHTO Specification Limits 93 VII Criteria for Using Metallic Coated Pipe Without Supplemental Organic Coating 94 VIII Typical Material Costs for Flame Spray Coatings for Abrasion Resistance 96 IX Alternative Coating Costs Compared to Existing Coating Systems 97 X Primer Adhesion to Galvanized Culvert Sheet 99 XI Asphalt Adhesion to Galvanized Culvert Sheet 101 XII Summary of State Specifications 102 . SUMMARY One of the primary methods of extending highway culvert life is to apply a protective coating. The purpose of this study is to evaluate the performance of the coatings used and to determine if better performance can