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为了研究路用混凝土中的钢筋在冻融循环-氯盐侵蚀-荷载多因素耦合作用下的锈蚀行为,利用开路电位法和动电位扫描法测定钢筋的自腐蚀电位、腐蚀电流密度和腐蚀速率。结果表明:与施加0.3应力比的相比较,施加0.4应力比的试件钢筋脱钝时间提前了50多个循环,高应力比缩短了钢筋脱钝的时间,增大了钢筋发生锈蚀的风险;极化曲线整体负移,阴极反应被抑制,在脱钝后钢筋的阳极溶解过程阻力变小,反应朝易于腐蚀的方向进行;腐蚀速率与腐蚀电流密切相关,100次冻融循环后,腐蚀电流密度和腐蚀速率分别表明钢筋将在10～15年内发生锈蚀,并在2年后,混凝土表面产生腐蚀裂纹。
In order to study the corrosion behavior of steel bars in pavement concrete under the action of freeze-thaw cycles - chloride salt erosion-load coupling, the self-corrosion potentials, corrosion current density and corrosion rate of rebars were measured by open circuit potential and potentiodynamic scanning. The results show that compared with the 0.3 stress ratio, the time of applying the 0.4 stress ratio is more than 50 cycles, the high stress ratio shortens the time of steel de-duction and increases the risk of steel corrosion. The negative polarization reaction is negative and the cathodic reaction is inhibited. The resistance of anodic dissolution of the steel becomes smaller after the blunt bluffing, and the reaction proceeds in a direction easy to corrode. The corrosion rate is closely related to the corrosion current. After 100 freeze-thaw cycles, the corrosion current Density and corrosion rates respectively indicate that steel bars will rust in 10 to 15 years and corrosion cracks on the concrete surface after 2 years.