MDOT - Michigan Department of Transportation

Transverse Post-Tensioning of Side-by-Side Box Beam Bridges

Multicell box sections are one of the most common types of cross-sections adopted for the construction of Michigan highway bridges due to their distinctive advantages over other typical T-beam and I-beam sections. However, several issues need to be addressed to improve the performance of side-by-side box beam bridges. These issues include: (1) replacement of interior/exterior damaged bridge beams due to deterioration or high load impact (2) longitudinal cracks in the deck slabs between the box beams due to lack of adequate post-tensioning and joint detail , (3) deterioration of concrete and corrosion of steel strands resulting from leakage,(4) unbonded transverse post-tensioning(5) alignment of post-tensioning ducts due to differential camber of box beams of skew bridges, and (6) part-width construction for wide bridges. These issues mandate significant increase in maintenance cost to replace damaged beams and to restore the load carrying capacity of this type of bridge. Therefore, a practical approach to address these issues needs to be researched for successful and practical field implementation. To address these issues, a research investigation comprised of an experimental program and theoretical analysis is proposed.