Joint Base San Antonio (JBSA) Lackland’s Kelly Airfield (Figure 1) has only one runway. Major expansion of the airfield was conducted during the early 1940s. In the mid1950s, Runway 15- 33 was constructed and the airfield was expanded to its present-day configuration. In some cases, World War II-era or earlier pavements were overlaid with additional concrete to achieve final thicknesses and elevations. Since the 1950s, airfield pavements have been removed and replaced, overlaid, or repaired. Substantial repairs to the runway keel sections occurred in the late 1980s. Apparently, airfield construction records were not transferred to JBSA-Lackland when the real property was transferred in 2001. It is open 24 hours a day 7 days per week. It has concrete slabs that are sinking due to pour subbase. These slabs are located at the intersection of Taxiway Hotel and Delta and the runway. These slabs are 14 inches thick and are original construction.
FedCon/South Bay Joint Venture is tasked to:
Stabilize subgrade and lift slabs of JBSA-Lackland’s Kelly Runway at the intersection of Taxiway Golf, Taxiway Delta and the runway. Stabilize subgrade and lift slabs of about 36,000 square feet of slabs through the use of deep injection of Uretek or equivalent.
Independent Testing shall be done on the whole project site prior to first drill at the cost of the contractor. Written test results shall be submitted and will be reviewed by the Government.
For bidding purposes use one injection at 4 feet and one injection at 7 feet. After all slabs have been tested government engineers will verify the number of injections and the depth of those injections needed.
Drilling shall begin during immediately after testing.
The slabs are non-reinforced at 14 inches thick Portland Cement Concrete. The contractor shall inject at depth determined by the test results to consolidate the subgrade, fill voids, remove water away from these areas and lift the slab to level within a 1/16th of an inch with surrounding stabled slabs. If the slab is too high the contractor at their own expense shall grind down the high points and reestablish the concrete grooves to the proper depth. If the slab is too low more material shall be injected to raise the slab. Injections shall be made based on test results.
The runway hard closure is only a few days per month. When the runway is opened after a hard closure there shall not be any debris, loose concrete chips, spider cracks, rocks, greater than 1/8” difference between slab elevations or greater than 2 inch crack. Plan ahead and review the survey to make sure there will not be a greater than 1/8” difference between slab elevations. This paragraph is not referring to final inspection but only during construction between hard closures.
Spall repair 3 inches deep and 6 inches beyond any surface cracks created by the hammer drill or any other work done due to this project. It is the contractor’s responsibility to take pictures of existing conditions in order to not be held reasonable for existing cracks, or spalls. Use CTS Rapid Set or equivalent for spall repairs.
Clean, insert backer rod and asphaltic joint seal that meets the FS-SS-S- 1401C requirements per specifications to repair full length of all joints due to movement of the slabs, age of joint seal or existing damage.
No Foreign objects (rocks, sand, trash…) shall be left on the runway for any length of time. Sweep continually. No supplies, tools, materials shall be left outside of the laydown year overnight All objects shall be placed in the lay down yard.
Testing (36,000 square feet)
Drilling, injection, raising the slabs and spall repair (36,000 square feet)
Assume 4 and 7 feet injections over the whole 36,000 square feet.
Spall repair caused due to breaking slab (4 inches deep and 6 inches from the bad concrete edge)
Slab replacement (25 X 25 ft slab being demoed and replace with four 12.5 X 12.5 ft slabs)
Dowels (1 inch dowels at 12 inch centers)
650 Flex Mix design with 7 day cure time
Clean, backer rod and Joint seal
Grinding and reestablishing the grooves
Route, clean and asphaltic seal cracks