Shrinkage and creep effect analysis of beam-arch composite bridge based on field test

To study the time-dependent behavior of the beam-arch composite bridge under the effects of shrinkage and creep, this paper conducted field tests on C55 concrete with different reinforcement ratios at the bridge site environment. Based on the experimental results, the commonly used CEB-FIP-90 model in engineering was modified, and new shrinkage strain and creep coefficient values were proposed. These modifications allowed for an analysis of the long-term performance of the bridge. Finally, the influence of the arch rib stiffening on longterm performance was discussed. The results indicate that the modified model aligns better with the actual structure compared to the CEB-FIP-90 value. During the operation stage, the bridge exhibits an overall significant compressive stress reserve. Specially, it is worth noting that the concrete footings experience tensile stress, which indicates a risk of cracking during the operation stage. Furthermore, the deflection of the beam-arch composite bridge is 1/7 of that of the continuous rigid frame bridge while the stress distribution in the beam-arch composite bridge is more uniform. This paper provides important reference value for the maintenance and management of beam-arch composite bridges during their operation period.