Investigations have confirmed that most bridge deck expansion joints leak and contribute more than any other factor to deck and substructure corrosion from de-icing salts. For this reason joint-free integral bridges, with the abutments structurally connected to a continuous deck, are more durable and cheaper to maintain. However, thermal strains in an integral deck cause cyclic loading on the soil behind the abutments, which may result in the development of passive soil pressures. One method of avoiding the development of high lateral pressures is to use a low stiffness but compressible elastic backfill as a stress absorbing layer behind the abutment. This report identifies various compressible materials, for example polymeric and geocomposite materials, which may be suitable for use as innovative structural backfill behind integral bridge abutments. (A)
Abstract