Thermal Field Distributions of Girder Bridges with GFRP Panel Deck versus Concrete Deck

Abstract

Temperature effects have always been considered to be one of the critical issues that affect the performance of traditional concrete and steel bridges. Currently, glass fiber-reinforced polymer (GFRP) composite panels, with the advantages of high strength, light weight, good corrosion resistance, long-term durability, etc., have been applied to slab replacements in bridge engineering. The thermal behaviors of these GFRP bridges, however, have not been fully understood. More specifically, the current temperature design specifications in the AASHTO LRFD may no longer be valid for GFRP bridges. Therefore, this paper presents the thermal field distribution behaviors through studying an as-built bridge with GFRP sandwich panels. First, a transient-state numerical modeling method is proposed. This method is capable of predicting the temperature field of a GFRP bridge based on local environmental conditions. Then, a parametric study is conducted to analyze the thermal responses of bridges with different structure combinations (i.e., GFRP panels, concrete slabs, concrete beams, and steel girders). The mechanical and physical properties of GFRP panels are predicted using the micro-macro mechanics theory and validated by a field measurement and an experimental study. Based on the results from the present study, the temperature distribution patterns for GFRP panel bridges are proposed, referring to the available AASHTO LRFD sign code. The thermal strains and stresses caused by temperature gradients along the depth of bridge superstructures are examined.