Surface deflection and pavement thickness criteria for the reconstruction of rural roads subjected to heavy log traffic

The growth of the wood chip industry in Tasmania has resulted in a significant increase in the number of log trucks taking timber to the chip mills. These trucks have a control placed on gross weight but not on individual axles. This results in axle loadings commonly exceeding limits placed on other commercial vehicles. When the log trucks use roads, originally designed for low volume traffic with a few commercial vehicles, pavement failure often occurs. In this paper the results of a research project, aimed at establishing surface deflection and pavement thickness subgrade CBR criteria for reconstruction of sections of these failed roads, are discussed (a).