东莞东江大桥防腐涂装设计

Design of Corrosion Protection Coating for Dongguan Dongjiang River Bridge

东莞东江大桥为刚性悬索加劲连续钢桁梁桥,桥位处于较严重的腐蚀环境。通过对环氧富锌底漆、醇溶性无机硅酸富锌底漆、水性无机硅酸富锌底漆和喷涂金属等钢结构外表面常用防腐体系的性能指标比较,针对不同结构部位的特点,综合考虑耐久性、环保性、经济性和可维护性,主桁外表面和螺栓头采用环氧富锌体系防腐;纵、横梁和检查车采用水性无机富锌体系防腐;高强螺栓摩擦面采用电弧喷铝防腐;箱形杆件内表面采用淡色改性环氧沥青漆防腐;钢防撞栏采用镀锌层加封闭漆防腐;人行道栏杆采用涂塑防腐;泄水钢管采用热浸锌防腐。

Dongguan Dongjiang River Bridge is a continuous steel truss girder bridge stiffened by rigid suspension members and the site where the bridge is located is in the severe corrosion environment.Through comparison of the performance indices of the epoxy zinc rich premier,alcohol-soluble inorganic silicate zinc rich premier,water-base inorganic silicate zinc rich premier and spraying metal that have been commonly used as the corrosion protection systems for the exterior surfaces of steel structure,in the light of the characteristics of the different structural parts of the bridge and also in comprehensive consideration of the durability,environmental protection,cost-saving and maintainability,it was determined that the epoxy zinc rich coating system was to be used for the corrosion protection of the exterior surfaces and high-strength bolt heads of the main trusses,the water-base inorganic silicate zinc rich coating system for the stringers,cross beams and inspection trolley,the electric arc spraying aluminum for the frictional surfaces of the bolts,the light color modified epoxy asphalt for the interior surfaces of the box members,the galvanization layer and sealing paint for the steel crush barriers,the resin coating for the balustrades on the sidewalks and the hot-dipped galvanization for the drainage steel pipes of the bridge.