MR87-1_REDUCED.pdf

Evaluation of Hi ghway Culvert Coating Performance; Report No .FHHA/BD- 80/059, June 1980 , Final Report.CONCLUSIONS1. Durability problems a re ,e ncountered with all protectivecoatings now commonly used .2.Al ternate methodsother than organicadvantage at r:lanyfield study .are available tocoatings and couldof the locationsprotect culvertshave been used toinspected in the3 .Organic coatings are,under abrasive streamby themselves ,flow conditi ons .not: satisfactory(4 .The durability of polymer coatings depends o n thealllount of salts in the soil o r water, the continuity ofthe coating, the pil and the abrasiveness of the bed ­load . Improvements are needed in production techniquesto prevent damage which adversel y affects performance.Polymer coatings a re satisfactory where abrasive f l O\~sand high salt conditions are not encountered.5.Asphalt adhesion to aluminum is poor.would not be satisfactory in abrasiveenvironments .This coatingor corrosive6. Epoxy coatings and vitrified clay liners are effectivewhen used on concrete i n acidic streams . They mighta l so be useful on corrugated metal under certain severeconditions .7 .Adhesion between asphalt and galvanized steel can beimproved through the use of s urface treatments andprimers . The benefits of improved adhesion should beeval uated .8 .Asbestos bonded aspha l t coating isab l e than plain aspha l t coating butdeterioration in abrasive or highsomeHhat more dur ­is also subject tosal t env ironments.9. The durability of asphalt coatings is influenced byapplication procedure , adhesion to the substrate ,seasonal temperature changes, water asorption, turbul ence in the stream flow and abrasiveness of thebedloilrl. Asphalt iE satisfactory ...,here abrasive flmoJ5and high sa1.t conditions arc not encountered.10. Asphalt mastic is not a durab l e coating.11. Asphalt compositionsource of crude oil.var ies Vlidely dependingPerformance variations ofon theculvert- 93 -