English：

Through the investigation of the damage of the anti⁃collision walls of 10 old bridges alongBeijing section of Beijing⁃Lhasa Expressway,it is found that the surface concrete of these anti⁃collisionwalls has undergone severe carbonation and spalling. This has led to extensive corrosion and exposure ofreinforcing steel, with the component deficiency condition rated as grade 2 ( the most severe). Suchdeterioration adversely impacts the service life and structural safety of the bridges. This paper analyzesthe damage mechanisms of the anti⁃collision walls in this section and subsequently conducts experimentalsimulations on the application of ultra⁃high performance concrete (UHPC) for their repair. Emphasis isplaced on evaluating the workability of UHPC under non⁃standard curing conditions. Additionally,mechanical influencing factors of the UHPC⁃NC interface are analyzed using samples from actualengineering practice. Finally, a comparative analysis is performed between UHPC and various repairmortars in the design phase. A refined treatment plan is proposed, along with corresponding constructionmethods and requirements, to enhance the repair quality of anti⁃collision walls.