Award of Excellence: Transportation Category
Sunshine Skyway Bridge Trestle Span Repairs
Tampa Bay, Florida
Submitted by Sika Corporation
Intron Technologies, Inc.
Lyndhurst, New Jersey
University of Florida
The Sunshine Skyway Bridge is one of the most recognized structures in the United States. With its signature bright yellow stay cables, the bridge resembles a sailboat, with its towers holding up the triangular sails across Tampa Bay. At the time of construction, it was the world’s longest bridge, having a cable-stay main span with an overall length of 5-1/2 miles (8.8 km). The main span is 1200 ft (366 m) and the vertical clearance is over 190 ft (58 m).
Shear cracking was observed during routine inspections of the trestle span girders. The inspection history indicated that the number of cracked beams had increased over time. In addition to the deficient AASHTO girders, cracks were observed in numerous pier caps. In some cases, these cracks were very large and exhibited visible signs of water penetration and damage.
The shear cracks in the AASHTO girders and the pile caps were epoxy injected. All spalls were patched using a cementitious repair mortar. All uneven surfaces were filled in with a leveling mortar and all bugholes and smaller cavities were repaired using an epoxy paste. In addition, a clear protective sealer was applied to protect the concrete further from moisture and chloride intrusion.
The deficient girders also needed to be structurally strengthened to carry additional loads. The use of a carbon fiber system was chosen to structurally repair the girders.
By planning out the construction sequence and using a well trained work force that had previous experience working with CFRP materials, the job was completed one month ahead of schedule.