Thermal Field Investigations and Applications to Integral Abutment Bridges with FRP Panels

Abstract

Expansion joints are often considered as one of the most vulnerable elements affecting the sustainability of traditional jointed bridges. Over the past several decades, a new type of integral abutment bridge (IAB) has been proposed, where the joints are eliminated at the abutments and/or along the length of the bridges. Although with wide acceptances, the IABs have not been largely applied in practice. Many arguments are unsettled and there are no national design guidelines currently. Among all, the thermal behavior is one of the most concerned issues, and that, to a large extent, limits the maximum length of IABs that can be constructed. Under this circumstance, a new type of fiber reinforced polymer (FRP) materials, with special material properties, are considered as an alternative to replace the traditional concrete and steel materials. However, the studies on the performances of both IABs and FRP bridges are not adequate. Therefore, an investigation on the thermal behaviors of IABs and FRP bridges is conducted. Then, an effort is made to analyze the responses by combining the FRPs with IABs, and to verify that such a configuration will help resolve the thermal issues of IABs. For FRP bridges, (1) the temperature distributions of a GFRP panel are discussed based on a field monitoring program conducted at the state of Kansas; (2) the influencing factors on the temperature distributions are studied, including the material property, environmental condition, and section hollowness; (3) the thermal gradients of the FRP panel bridges are proposed referring to the AASHTO LRFD design code; and (4) the jointed bridges’ performances, after replacing traditional slabs by FRP panels, are numerically analyzed. For IABs, (1) the thermal responses of the first full IAB in the state of Louisiana, Caminada Bay Bridge, are discussed based on a field monitoring program; (2) a parametric study is employed to analyze the effects of different parameters on the thermal performances, including the soil types, bent-pile connections, loading types, and support conditions; and (3) a numerical study is performed to verify the assumption that applying FRP panels on IABs will help resolve the thermal issues of IABs.