缆索桥梁拉索钢丝腐蚀测试方法

Corrosion Test Method for Cable-stayed Bridge Steel Wire

针对缆索桥梁腐蚀监测难的问题,以平行钢丝拉索镀锌高强钢丝为对象开展加速腐蚀试验,采用电阻法与传统称重法进行了腐蚀试件截面损失率对比测试,并分析了腐蚀物与温度对腐蚀电阻的影响,以此对电阻法进行钢丝腐蚀的监测和评估工程中应用的可行性进行论证。结果显示,电阻法与称重法测试具有相近的结果,在坑蚀时,两种测试法的偏差均值为3.8%,而在均匀腐蚀时的偏差均值仅为2.5%,两种腐蚀类型误差均较小,满足工程要求,因此,通过电阻法测试与评估拉索钢丝腐蚀率是可靠的。拉索钢丝温度和腐蚀物对腐蚀电阻的影响试验结果表明,腐蚀前后钢丝试件的温度系数与普通钢材接近,其值为0.00605,腐蚀物对腐蚀电阻的测试结果无明显影响,即在进行缆索桥梁拉索腐蚀监测时,腐蚀传感器的温度补偿及腐蚀量的计算时可不考虑腐蚀物的影响。

To solve the problem of difficult corrosion monitoring for cable-stayed bridges,the accelerated corrosion test was conducted on the galvanized high-strength steel wire used in the parallel steel wire suspension cables.The corrosion loss rate of test specimens was compared by using electric resistance method and the traditional weighing method.The influence of corrosion products and temperature on the corrosion resistance was analyzed to verify the feasibility of using electric resistance method for monitoring and evaluating the corrosion rate of steel wires in engineering applications.The result indicates that the resistance method and the weighing method have similar test results.The average deviation between two methods in pitting corrosion is 3.8%.The average deviation in uniform corrosion is 2.5%.The errors in both corrosion types are small and meet the engineering requirements.Therefore,it is reliable to monitor and evaluate the corrosion rate of suspension cable steel wires by using the resistance method.The experimental results on the influence of temperature and corrosion products on the corrosion resistance of steel wire specimens show that the temperature coefficient of steel wire specimens before and after corrosion is close to that of ordinary steel,with a value of 0.00605.The corrosion products have no significant influence on the test result of corrosion resistance.Therefore the temperature compensation and calculation of corrosion in cable-stayed bridge suspension cable corrosion monitoring can be ignored when the corrosion sensor is used.