AN EVALUATION OF RETROFIT LOAD TRANSFER MATERIALS AND DOWEL BAR CONFIGURATIONS

Abstract

The Minnesota Department of Transportation (Mn/DOT) constructed experimental test sections of retrofit load transfer across transverse cracks in concrete pavement on U. S. Highway 52 near Zumbrota, Minnesota. The test sections were constructed in September of 1994 to evaluate retrofit load transfer and the effects of different dowel lengths and configurations, and patching materials on performance. The retrofit dowels improved the load transfer efficiency (LTE) of the worst cracks from 23% to more than 80%. After 6 years, the LTE has remained above 80% for all of the test sections, there have been no visible failures of the repairs and very little additional faulting has occurred in any of the configurations, although several repairs exhibited plastic shrinkage cracks and bond failures along the vertical faces of the slots.