Thermal response analysis of reinforced concrete box girder during hot-mixed asphalt mixture paving

Abstract

Hot-mixed asphalt (HMA) concrete has been extensively used in the concrete box-girder bridge deck pavement due to its excellent performance and driving comfort. Nevertheless, during HMA concrete construction, the high paving temperature may disturb the thermal field of the bridge, thereby causing the significant thermal response throughout the box girder. Therefore, this research aims to investigate the temperature behavior and thermal stress of a reinforced concrete box girder segment during HMA concrete paving. The transient thermal field theory and element deletion method were first adopted to establish a three-dimensional finite element model of a reinforced concrete box girder segment and simulate the dynamic paving process, respectively. Subsequently, the bridge monitoring data was used to validate the thermal field model and then the temperature distribution analysis was conducted. Finally, the thermal stress in the bridge was studied in cross-sectional area. Results demonstrate that the vertical temperature of the concrete box-girder during the paving process is declined with the increasing vertical distance to SFRC leveling layer, and its highest value occurs at 36min after starting to paving. Furthermore, in the vertical direction, the west web-plate is subjected to compressive stress at locations of two ends and tensile stress at locations of the middle. Meanwhile, the thermal stresses undergo a decline trend after short-term growth both in the box and flange slab in the transversal direction.