Durability Assessment of Concrete Bridge Slab Rehabilitated by Joint-Elimination Method

摘要

Expansion joints in bridge slabs are designed to absorb horizontal displacement due to the temperature fluctuation and moving vehicular load. The expansion joints, however, are very often damaged due to a repeated loading of the moving vehicles. The joints in the existing simple span structures can be eliminated by converting the structural types into continuous spans. When existing simple span bridges are converted into continuous spans, rigid (pin and roller) support conditions have to be changed to elastic supports in order to absorb and distribute the energy of horizontal motion due to an earthquake loading. However, development of additional reaction forces and stresses on the concrete slab due to the unequal displacement of the elastic supports have been overlooked. In this study, two-span continuous specimen, which is converted from two simple span structures is tested and analyzed to investigate the stress distributions of the concrete slab. Durability of the concrete slab under the service load is also discussed. The results of this study show that the change of strain in the longitudinal direction can be reduced by using the elastic supports and the vertical shear stress increases, directly affecting the fatigue life of the concrete slab.