Expedient Spall Repair Methods and Equipment for Airfield Pavements

Abstract

Selected equipment and procedures were evaluated to expedite repair of spalls with rapid-setting materials. The objective was to develop one or more methods to excavate and prepare a 2-ft2 × 4-in. deep spall for placement of a rapid-setting repair material in 15 min or less. A secondary objective was to correlate various excavation methods with a relative life expectancy of the repair. For five excavation methods, 2-ft2 × 4-in. deep spalls were excavated in triplicate. The spalls were subsequently repaired with a commonly used rapid-setting spall repair material. The efficacy of the repair methods and equipment were evaluated on the basis of petrographic examination of the substrate excavation, production rate, total production rate, in situ tensile pull-off strength, direct shear bond strength, and performance under simulated F-15E wheel loading. Each of the methods evaluated had a significant improvement in production rate over the 30-lb jackhammer, the standard Department of Defense spall repair excavation method. The most efficient method was a cold planer, which, on average, was approximately 58% more efficient than the jackhammer. Of the methods evaluated, only the cold planer could meet the requirement of excavating a 2-ft2 × 4-in. deep spall in no more than 15 min.