Accelerated Performance Testing of Category 2 Two-Coat Bridge Coating Systems--Kentucky Highway Investigative Task No. 61

KYTC personnel seek to obtain coatings perfonnance test results on two-coat systems for current and future use on maintenance painting of steel bridges. Those systems shall incorporate an organic zinc primer and barrier/weathering resistant topic. The coatings systems to be tested will be used for blast-cleaned steel to a standard below SSPC SP-6 (Commercial Blast Cleaning). Coatings systems that pass the tests (according to KITC review) will be placed on Category 2 qualified products lists for selection by bridge painting contractors. For paint manufacturers to have coatings systems qualified, they must contact the KITC Division of Maintenance and propose to submit samples of standard coatings that confonn to their standard product data sheets. Samples of coatings systems will be provided to the KITC Division of Materials for compositional testing and characterization. Remaining samples will be supplied to KTC for application on steel test panels and subsequent perfonnance testing and evaluation. KTC personnel will prepare steel test panels for painting and apply the coatings systems in the KTC spray booth. Companion panels will be coated with the KITC standard specification polyurethane coatings system. During and after the coatings application process, KTC technicians will measure the coating thicknesses and detennine the suitability of the painted panels for representative perfonnance testing of the coatings. After curing and preparation for perfonnance testing, 6 panels of the test coating system and 5 panels with the KYTC standard system will be tested for accelerated weathering (QUV) and accelerated corrosion (Prohesion) in accordance with ASTM 5894. Those tests will be perfonned in I 68-hour {l week) time blocks in each chamber in the order: QtN testing followed by Prohesion testing. After each 1,008 hours of tests (6 weeks), the test panels will be removed from the test cycle in evaluated for rusting, scribe undercutting, blistering, gloss retention and color stability. The panels will be photographed and the results reported to KITC paint personnel at each 1,008 evaluation point. The testing will run for 5,040 hrs (30 weeks). KTC personnel have developed 7 Standard Operating Procedures that detail the work to be performed from receipt of the coatings systems through testing, evaluation and reporting (including timelines for report submittal). The SOPs will serve as the basis for all work conducted under this KHIT. The coating manufacturers submitting the coatings systems will pay $3,000 for each coating system tested and KITC will also pay $2,500 (in direct costs). In addition, KYTC will provide $5,000 to provide for start-up (maintenance & calibration) of the test chambers and instrumentation. Up to six coatings systems will be tested under this study.