利用Wiener过程探究镁水泥混凝土中涂层钢筋在盐类环境下的腐蚀寿命

采用氯盐溶液和硫酸盐溶液浸泡镁水泥钢筋混凝土构件,使构件中的涂层钢筋加速锈蚀,并利用电化学工作站进行电化学试验;以腐蚀电流密度作为钢筋耐久性退化指标,建立一元Wiener过程预测模型进行钢筋腐蚀寿命预测.结果 表明:在氯盐溶液环境下,镁水泥混凝土构件中的钢筋受腐蚀问题较之硫酸盐溶液环境更为突出,且涂层在2种盐溶液环境中均对钢筋起到了较好的防护效果;在氯盐溶液环境中,涂层钢筋在1500 d附近进入中等腐蚀阶段,在硫酸盐溶液环境中,涂层钢筋在22000 d进入中等腐蚀阶段.

Corrosion Life Investigation of Coated Steel Bars in Magnesium Cement Concrete under Salt Solution Environment Using Wiener Process

Ordinary silicate concrete cannot meet the durability demand of saline soil in northwest China. Magnesium cement, as a kind of special cement, has a good resistance to salt corrosion in the environment of salt erosion, but its use is limited because magnesium cement concrete has a certain corrosive effect on reinforcement. To solve this problem, a coating is used to protect the reinforcement in magnesium cement concrete. In the experiment, chlorine salt and sulfate solution were used to soak magnesium cement reinforced concrete members to accelerate the corrosion of reinforcement in the members. Electrochemical test was carried out by electrochemical workstation. The corrosion current density of electrochemical test parameter was used as the durability degradation index to establish a single Wiener process prediction model for corrosion life prediction. The results show that the corrosion problem of steel bars in magnesium cement concrete is more prominent than that in sulfate solution, and the coating has a better protective effect on steel bars in both salt solution environments. In the chlorine solution environment, the coated steel bar entered the medium corrosion stage around 1500d, while in the sulfate solution environment, the coated steel bar entered the medium corrosion stage at 22000d.