Evaluation of Load Transfer Restoration Techniques and Undersealing Practices

摘要

The report presents results of an investigation conducted to evaluate the performance of 'retrofit' load transfer devices installed at a test site on I-75 in Georgia. Devices installed include dowel bars placed in slots and Double V devices placed in holes drilled along joints. Measured deflection data at the test site are compared with deflections calculated using a modified version of computer program JSLAB. The modified version of the program allows calculation of deflections of loaded slabs that are initially curled upward. Calculated results indicate that there is no clear difference in calculated responses of joints using retrofitted dowel bars and Double V devices. However, field deflection data and visual observations of test sections indicate that sections retrofitted with dowel bars are generally performing better than sections retrofitted with Double V devices. Poor performance of some of the test sections using the Double V devices is attributed to field problems encountered with use of the patching materials. These problems may preclude achievement of desirable level of performance with Double V devices. Retrofitted dowel bars can be expected to provide a desirable level of long-term performance when used with commonly available patching materials.