Naples Bay Yacht Storage River Point Drive, Naples, Florida
Pavement between (3) buildings serving as the runway for a mobile boat-lift weighing 170,000 lbs. when fully loaded carrying boats to and from the loading dock on the bank of the Gordon River.
Lack of weather protection at the construction cold joints along the perimeter allowed corrosion of the post-tension cable live ends and subsequent sudden release of their stored potential energy. The explosive nature of this defect was determined to be a safety hazard after several impacts at the opposing ends. Reduced capacity due to loss of induced compression combined with the 80% concentrated load distributed to the solid front wheels of the lift resulted in permanent deformation of the slab and eventual punching shear failure.
The remaining post-tensioned cables were carefully neutralized by controlled cutting allowing the existing 8" concrete slab to be broken into segments and removed. The open area was then excavated deeper to receive a compacted sub-base of crushed stone followed by installation of a two-way mat of reinforcing at the top and bottom consisting of epoxy coated bars. To control cracking the large expanse of the drive slab was subdivided by contraction joints at regular intervals that were saw-cut over designed gaps in the reinforcing. Isolation joints were installed along the outer perimeter with asphalt impregnated fiberboard against the existing adjacent building foundations. All joints were fit with backer rod and / or topped with an industrial traffic grade sealant.
30,000 Square Feet Slab Replacement
7,000 Lineal Feet Control Joint Installation
80 Lineal Feet Heavy Duty Trench Drain Retrofit
Start to Finish: (3) Months
Total Cost : $1.5 Million