Preservation of Missouri Transportation Infrastructures: Non-Destructive Testing of FRP Materials and Installation, Gold Bridge; Final rept

摘要

The FRP (Fiber Reinforced Polymer) retrofit of a concrete bridge (Gold Bridge, P-0962 in Dallas County) in Missouri provided the opportunity to use new and existing technologies to test the FRP materials installations, and performance. Four different parameters were investigated; concrete surface roughness, FRP fiber alignment, FRP delamination, and FRP bond pull-off strength. Results of testing to date are presented, and longer term monitoring plans will be given. Surface substrate roughness measurement of sand blasted surfaces was made, on selected locations of the bridge abutments and bents, as well as the bridge deck, using a newly developed laser profilometer. The roughness measurements are compared to the 'idealized surface roughness,' and compared against any potential future delamination, from pull-off tests and natural delamination. FRP fiber alignment measurements were made using an imaging technique that measures the angle between control lines and special tracers embedded in the FRP materials. FRP delamination testing was done using a specially modified impact echo tester, on production surfaces and on surfaces with artificially created delaminations. All test sites are referenced with respect to previously determined substrate roughness measurements. Tests were performed periodically for five years. FRP bond Pull-off strength testing was done using a specially designed pull-off tester. Pull-off plugs were installed on selected locations on the bridge and referenced to roughness measurements; pull-off tests were performed periodically for five years.