Fire damaged box girder inspection and assessment and strengthening treatment

Abstract

Based on a fire accident in a bridge of the Jinan-Qingdao high-speed railway, the preliminary damage assessment of the box girder was conducted through surface inspection, concrete strength testing, concrete carbonation depth testing and reinforcement protective layer thickness testing methods. Then a corresponding numerical model of the fire damaged box girder was created by the Midas software, and the heat transfer analysis and thermal stress analysis were carried out. The results showed that the fire damaged level of the box girder were Grade II (moderate damage). Finally, the corresponding reinforcement measures were recommended.