A research project at Silver Bay Municipal Airport evaluated six different repair methods alternated along the 3,200-foot bituminous runway. In 1986, the runway developed significant transverse cracks and needed repair to maintain aircraft operations. The Minnesota Department of Transportation (Mn/DOT) and Ralph Burke Associates (RBA) identified 17 cracks for repair and analysis. Over the past seven years, Mn/DOT, RBA, and others monitored the repair behavior of the methods.
The 17 patches experienced variable behavior since the first inspection in 1987. Although most repairs experienced differential heaving, one type of repair moved with the surrounding pavement. The method used similar base material and a T-shaped cross section to distribute any movement over a larger area. The T-section, the repair that performed consistently well, was chosen to replace three of the badly faulted patches.
These second-generation repairs were completed in October 1994 and monitored over the next 15 months. The results further confirmed the consistently good performance of the T-section repair, making it the clear recommendation over the other designs evaluated in this project.
