机荷高速公路高性能耐候桥梁钢适应性关键技术

Research on Key Technologies of Adaptability of High Performance Corrosion Resistant Bridge Steel at Jihe Expressway

与普通钢相比,耐候钢具有少涂或免涂装、环境友好等特点。为研究其在我国华南地区的适应性,以正在进行改扩建的机荷高速公路为例,对沿线具有典型代表的福民、白泥坑和荷坳3地的环境数据及腐蚀因子数据进行采集,并同步开展3个钢种挂片曝晒试验。结果表明,机荷高速公路沿线腐蚀性等级属于C2类,具备免涂装使用耐候钢建造桥梁的环境条件;1年的大气曝晒结果表明,3种耐候桥梁钢在白泥坑的腐蚀最重,3%Ni钢的耐蚀性最好,1%Ni钢的锈层最致密,但3种钢的腐蚀速度均小于0.02mm/a;将实测Cl-沉积率数据进行回归,得出Cl-沉积率与海岸线距离的关系。

Being compared with ordinary steel,weathering steel has the characteristics of less coating or no coating,and environmental friendliness.In order to study its adaptability in South China,taking Jihe Expressway which is undergoing reconstruction and expansion as an example,environmental data and corrosion factor data of Fumin,Bainikeng and Heao which are representative of the typical along the line have been collected,and simultaneously three steel strip exposure tests have been carried out.The results have shown that the corrosive grade along Jihe Expressway line belongs to the C2 category which has the environmental conditions for the construction of bridges without the use of weathering steel;the one-year atmospheric exposure results have shown that the three weather-resistant bridge steels are the most heavily corroded in Bainikeng,3%Ni steel has the best corrosion resistance,and the rust layer of 1%Ni steel is the densest,but the annual corrosion rate of the three steels is less than 0.02mm/a;the measured Cl-deposition rate data is regressed to obtain the relationship between the Cl-deposition rate and the coastline.