Temperature Distribution And Effect Analysis Of Steel Bridge Deck During Asphalt Pavement Paving

Asphalt concrete is the mainly material that widely used in long-span bridge, however, local temperature deformation of steel deck plate incited by the high-temperature paving appears constantly, and the local temperature deformation has an adverse effect on the performance of bridge deck layered composite system, while the temperature effect is not taken seriously at this present stage. Therefore, this paper relies on the National Natural Science Foundation of China "Study on Temperature Effect of Steel Deck Plate Paving Based on Transient Heat Transfer Theory" (No.51378122), using the in-situ monitoring and numerical simulation to analyze the thermal field characteristics of the steel bridge deck during the asphalt pavement paving. Moreover, the interface temperature effect induced by the high-temperature asphalt pavement paving was subsequently analyzed.Firstly, the in-situ monitoring of a steel bridge in China was conducted to monitor the temperature changes of the steel bridge deck during the gussasphalt pavement paving, and the 3-D temperature distribution of the steel bridge deck was summarized. Monitoring results show that, the temperature of steel deck plate increases first and then decreases over time, and the temperature of the steel bridge deck in the paving area reaches the highest at 20min after the paving, approximating 120℃. Moreover, the transversal and longitudinal temperature distributions of the steel bridge deck present distinct hysteresis, and the temperature differences among the cross-sections depend on the paving speed, the initial temperature of pavement and the steel deck is in the heating-up condition or pull-down condition.Secondly, a thermal field numerical model of steel box girder was established based on the transient thermal field theory and the heat-conduction theory, and the element deletion method was applied to simulate the paving construction process. Subsequently, the model was validated based on the measured results, and the validated model was used to further analyze the thermal field characteristic of the steel bridge deck during the paving. The numerical results show that, the maximum temperature difference occurs in the stiffener at 14min after the paving, when the structure undergoes the worse stress. The temperature distributions of the steel bridge deck in different cross-sections present a similar regularity, and the transversal temperature changing area of the steel bridge deck lies in the region that is about 0.4m on both sides of the pavement edge. In addition, the temperatures of the bridge deck around the stiffener and diaphragm plate are lower than the other regions, but the influence of the stiffener and diaphragm plate is slight.Thirdly, the effects of the construction reason, paving materials, pavement thickness, et al., on the temperature distribution of the steel bridge deck during the paving were analyzed by the numerical simulation. The results show that construction season, paving materials, pavement thickness, solar radiation and the winds have some effect on the paving temperature field. Therefore, the temperature effect in the steel bridge deck during the paving could be reduced by the optimization design of the steel bridge pavement system and the reasonable selection of construction conditions. Moreover, the critical temperature load equation considered construction season, paving materials, pavement thickness, solar radiation and the winds was established based on the numerical results, which is expected to aid further development of thermal design criteria in bridge codes.Lastly, a steel box girder mechanics model combined with the composite solid was established, in order to analyze the interlaminar shear stress during pavement paving, and the shear test was taken simultaneously to discuss the influence of paving temperature field on the interlaminar shear performance. Besides, an orthotropic plate model based on the cohesive zone model was established to analyze the residual stress between the steel bridge deck and the waterproof bonding system during pavement paving. The results show that, the maximum interface shear stress between the steel bridge deck and the waterproof bonding layer lies at the pavement edge, and the construction season have a great influence on the interface shear stress distribution. The maximum interface shear stress is 185.4kPa when paving in the high-temperature season, and which is 347.5kPa when paving in the low-temperature season. Moreover, the shear strength of the waterproof bonding system is small during the high-temperature paving. Therefore, it needs to notice that the early damage may occur in the waterproof bonding system. In addition, the construction season have no influence on the interlaminar residual stress distribution, and the maximum interlaminar residual stress is 1.8kPa, which is conservative.The findings in this paper could provide a theoretical basis for the calculation of the temperature load of the steel bridge deck during the paving. Meanwhile, the findings could be applied to the reasonable selection of the bonding materials and the safety design of the bridge structures.