基于阳极梯传感器的高桩码头耐久性监测研究

Study on the long-term durability monitoring data for a high-piled wharf in a harbor with anode-ladder sensors

为了获取沿海高桩码头结构的耐久性能参数,基于阳极梯传感器在天津港一新建高桩码头设计部署了结构耐久性监测(SDM)系统,用于钢筋混凝土结构的耐久性监测。通过监测数据分析可知,阳极之间的电阻随环境温度的升高而降低,随环境温度的降低而升高;阳极梯传感器会受到温度和湿度的共同影响,导致传感器的某些阳极相对于阴极的电流出现异常,导致误判钢筋脱钝的情况。因此,需要结合电流、电压、电阻、温度等监测数据综合确定阳极的极化状态,不能简单地仅靠电流值来确定。

One structural durability monitoring(SDM)system for a high-piled wharf in the Tianjin Port of China is devised and deployed with anode-ladder sensors.The system can monitor the structural durability of reinforced concrete,which provides a means to monitor the state of steel corrosion for the wharf.After the installation,the monitoring data from the anode-ladder sensors was collected for 4 years.The appropriate signal from each sensor set in the site demonstrates the efficacy of the sensor setup methods used for the full-scale,continuous,autonomous SDM system deployed on the high-piled wharf in the harbor.Based on the monitoring data of 4 years,it is proven that the resistance of concrete will be significantly affected by the change in temperature,and the increase in temperature will cause the drop in concrete resistance.Furthermore,the anode ladder sensor will be affected by temperature and humidity,resulting in some of the sensor anode rod relative to the cathode current will exceed 15μA(rebar depassivation limit),reaching the rebar depassivation criteria,and the duration is up to 4-6 months.Therefore,the monitoring data for current,voltage,resistance,and temperature should be combined to determine the activation state of the anode,and cannot be determined simply using the current value.