RESTORATION OF JOINT LOAD TRANSFER

Load transfer at joints and cracks in concrete pavements greatly affects faulting, cracking, and spalling. The restoration of load transfer has been attempted recently by several highway agencies. The results of field performance studies of 369 restored joints and cracks located in 9 states are presented. Four retrofit load transfer devices were evaluated: round steel dowels, double-vee shear devices (without precompression or grooving), figure-eight devices, and miniature I-beam devices. Extensive field and office data were collected and analyzed. Models were developed to predict the relative performance of the devices. Results indicate that the round steel dowel bar did the best job of reducing faulting, and it showed no device or matrix failure. Additional research is under way to provide improved performance data. A recommended retrofit dowel design for joints and cracks is provided.