FIELD PERFORMANCE OF EXPERIMENTAL FULL-DEPTH REPAIR JOINT LOAD-TRANSFER SYSTEMS IN ILLINOIS

The Illinois Department of Transportation (IDOT) constructed 28 full-depth repairs with various dowel load-transfer system designs on I-70 in 1984. Design variables included dowel diameter, number of dowels per wheelpath, dowel anchor material, and the use of tie bars in lieu of dowels. IDOT and the University of Illinois monitored the faulting performance and loss of load-transfer efficiency of these repairs through 1988, when the project was overlaid. In general, it appeared that greater quantities of larger-diameter dowels improved leave-joint load-transfer efficiency; faulting improvements were less noticeable. Tied approach joints improved the load-transfer efficiency of both the approach and leave joints, presumably because repair movement was inhibited. The performance of repairs constructed using epoxy mortars was mixed. Repair leave joints generally performed more poorly than approach joints and were determined to be critical for design purposes. Repair leave-joint faulting was modeled as a function of load-transfer efficiency. Traffic and other important variables could not be introduced because they were relatively constant over the data base. The model that was developed was shown to have applications in repair load-transfer system design.