Innovative Use of Flowable Fill for Short-Span Bridge Rehabilitation

摘要

This project investigated the use of a liquid concrete-like material commonly referred to as flowable fill, to rehabilitate short span bridges and culverts commonly under the jurisdiction of local governments. The various methods in which this material can be used for bridge rehabilitation were explored and evaluated. The project entailed a comprehensive investigation into how other states have used flowable fill for bridge rehabilitation, study of a large-scale culvert-bridge rehabilitation conducted by the Alabama Department of Transportation Fourth Division near Wadley, Alabama, and four field demonstrations in Shelby County, Alabama. The study included the determination and discussion of the material properties of the flowable fill used in the demonstration projects, the development of methodology for bridge rehabilitation using flowable fill, and a costs and benefits analysis. The study found that there are several very important advantages offered by the use of flowable fill as backfill material for bridge rehabilitation including (1) cost efficiency, (2) expediency in returning traffic flow to normal, and (3) enhanced structural integrity and safety. Construction costs were found to decrease by approximately 40-50% compared to total replacement in most cases. The need to construct expensive detour bridges was eliminated.