This study investigates the stability technical condition of patina formed on the long lasting weathering steel plate girder bridge in the inland semi-arid areas.The Longfang Overpass of Huangling-Yan'an Expressway in Shaanxi Province is applied as a case.By analyzing the corrosion resistance mechanism of weathering steel patina and the environmental factors influencing the patina layer stability,periodic in-situ detections of patina stability on the Longfang Overpass(conducted in October 2021 and August 2023,respectively,with an interval of nearly two years)were carried out,and an evaluation model of the stability technical conditions of patina layers in bridges of such type was proposed.The results show that the adhesion force of patina layers on the Longfang Bridge has been enhanced over a period of near two years,and conditions such as sufficient sunlight,good ventilation,dry surfaces,and free of debris accumulation are conducive to the formation of a stable patina layer.Additionally,the vertical surface of the main beam,which is not prone to accumulating water and dust,is more likely to form stable patina layers than the horizontal upper surface.As the service life of the long lasting weathering steel plate girder bridge extends,the stability of weathering steel patina continues to improve at its formation stage.A patina layer maintenance strategy for the long lasting weathering steel plate girder bridge that suggests daily maintenance and patina grading maintenance is proposed.It is recommended to set up a V-shaped water baffle on the lower surface of the bottom flange of the steel girder near the girder ends,and a drip sink or water baffle for the concrete cantilever deck.
维普
万方数据