Abstract:
The Benkelman beam, a device for measuring the rebound of a roadway pavement after passage of a loaded truck wheel, has been used widely in Canada to aid in the design of high-quality asphaltic pavements. Its acceptance is due mainly to its simplicity, reliability, and ease of use in the field. The beam's use was proposed for both thickness design and evaluation of construction uniformity on lower quality, shorter lived, non-hard-surfaced forest roads in Canada, and a research program to meet this objective was begun in 1967. Preliminary trials conducted on a low- quality road used mainly for access traffic revealed no problems in using the beam without modification. The spring-fall rebound ratio was found to be generally higher than on public highways, and the effects of precipitation on rebound were found to be almost immediate. These findings were confirmed in further testing on a private hauling road. A full-scale test road has been developed to determine the beam's application in the design of forest roads. Difficulty was encountered in correlating road base thickness with rebounds measured immediately after compaction. Rebounds tend to reduce with use of the road.
Supplemental Notes:
Proceedings of a work shop held June 16-19, 1975, in Boise, Idaho by the Transportation Research Board.
