The federal, state, and local highway authorities in the United States invested $3.9 billion in therehabilitation of roughly 8,000 miles of pavement in 2008. This significant investmentemphasizes the importance of ensuring that rehabilitation techniques perform well to help reducethe high annual cost for repairs.The repair of pavement base layers using compacted lifts of crushed aggregate requiresspecialized labor and equipment, contributes significantly to total construction time, and is verydifficult to perform, particularly in restricted access areas, often resulting in a poorly constructedrepair and loss in performance. Flowable fill technology has shown some success when used forbackfilling patches and utility cut repairs.The purpose of this paper is to present the performance and cost advantages of using pre-blended flowable fill for rapid repair of damaged areas in highway and airfield pavements.Eleven commercially available flowable fill blends were evaluated using both laboratory andfield testing methods. The laboratory evaluation consisted of standard material characterizationtesting including compressive strength, flowability, hardening time, and excavatability. Fieldtesting included constructing and trafficking simulated utility cuts and full-depth patches inexisting pavements. An examination of structural capacity, surface deformation, and visiblesurface distress was conducted for each repair at regular traffic intervals. Additionally,construction time, difficulty, and cost were compared to a traditional aggregate repair.Testing results indicate that backfilling utilities and patches in pavements using flowablefill reduces the potential for premature failure, reduces construction time, and reduces totalproject cost while increasing repair performance.
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