Effect Of The Temperature Field Induced By The High-temperature Asphalt Paving On The Concrete Box-girder Bridge

Bridges are great symbols of mankind's conquest of space and they are the enduring expressions of mankind's determination to remove all barriers in its pursuit of better and freer world. With the rapid development of the economy, the transportation has made great progress, and the highway mileage is increasing fast. At the meantime, many different types of bridges, include lightweight, long-span, irregular bridges and new types of composite bridges, have been built around our country. Recently, temperature fluctuation effect on bridges have raised public concern. Most bridges experience daily and seasonal temperature variations which causes the material to shorten with temperatures decreasing and lengthen with temperature increasing. It has been observed that these temperature fluctuations have caused structurally deficient or functionally obsolete. Based on the theory of heat conduction, the theory of finite element method and field observation, contributions in the development of temperature fluctuations theory were made by various researchers, and many development in this field have been achieved. Due to anti-sliding property and the high degree of driving comfort, asphalt concrete pavement exhibit advantages over traditional cement concrete pavement, and has been widely used in newly built bridges. In order to improve the property of the pavement, many experiments have been conducted on asphalt concrete pavement based on field observation and finite element theory, but most of which are concentrated on short-span bridges. The research on long-span bridges is very scarce, and yet not well-rounded. This paper presents a case study by using finite element method on the Lunzhou Bridge, a long-span continuous box-girder bridge, also, a rigid frame prestressed concreted bridge, located in Qingyuan, Guangdong, China. The results will provide a theoretical reference for the follow-up of the real bridge test. And the research mainly concentrated on the following parts:(1) In the research a finite element analyses for the concrete box-girder had been performed, which was based on the Lunzhou Bridge by using ANSYS. And the parametric analysis was carried out depending on the contributing factors of temperature field of the finite element model. Also, optimal parameters of this high temperature paving finite element model were compared and selected, and the optimum temperature gradient has been achieved.(2) By using finite element method with Midas Civil, the structure is divided into the plane frame model, to take temperature gradient analysis and explore the high temperature paving impact on the integrity of the Lunzhou Bridge.(3) The data of temperature gradient has been collected, during the high temperature paving and a period of time after the paving was finished. The field observed internal stress results and the theoretical results based on the General Code for Design of Highway Bridges and Culverts has been compared and analyzed.