This paper presents the results of a field investigation performed to determine the impact of dowel misalignment on joint movements and potential for joint lockup on a section of a newly constructed concrete pavement in Florida. This section of the pavement, built under a design-build (D-B) contract, exhibited various types and degrees of dowel misalignment as determined by the MIT Scan device. Some of the joints in this pavement section exhibited dowel misalignments that were over Florida Department of Transportation’s (FDOT’s) specification limits. Lacking a widely accepted rejection criteria, the joint score methodology published by the Federal HighwayAdministration (FHWA) was used to identify joints that were considered problematic. Joint scores were computed for each of the joints as indicatedin the procedure. The scores generally ranged from 1 to 40 with a joint score of 1 indicating a perfectly aligned joint and 40 indicating a joint with a high degree of misalignment in multiple bars. The rejection criteria were initially planned to be based on the Joint Scores, however, based on a meeting between the owner, the designer, and the builder, it was decided that a novel approach to arriving at the criteria based on a direct measurement of the joint movements in the field was decided to be followed.This approach included measuring movements of joints with severely misaligned dowels and well-aligned dowels over a 48-hour period. The resulting data showed unexpected but conclusive evidence that suggested that more work needs to be done in establishing rejection criteria and corrective actions when dowel misalignment is detected in the field.
Samenvatting