A novel composite thermal insulation system for concrete bridge box girder and its influence

Abstract

The temperatures of a concrete box girder were observed through a field test, and the finite element method (FEM) model of the concrete box girder was established. The unknown parameters were inversed by using the constriction coefficient particle swarm optimization (CCPSO) algorithm, and hence the optimized numerical model of the temperature field close to the real-world temperature field was obtained. A novel set of composite thermal insulating system for a bridge is developed for the first time, in which the insulation coating on the outside surface of the box girder web and bottom plate is combined with the thermal insulation deck pavement layer of the bridge. The coating is insulating mortar consisting of gelatinous power and expanded polystyrene (EPS) pellets, and the insulation deck pavement layer is made of ceramsite asphalt mixture. The research results show that the proposed thermal insulation system can effectively reduce the average temperature and temperature gradient of the concrete box girder. In addition, the influence of the materials and thickness of deck pavement and coating on box girder temperature is analyzed. It provides theoretical guidance for reducing bridge temperature.

Keywords

• Concrete box girder
• Thermal insulation
• Thermal insulation material
• Coating
• Deck pavement
• Temperature field