受力钢筋在pH = 3的盐酸溶液中的锈蚀及力学性能退化规律

Corrosion and Mechanical Properties Degradation of Stressed Steel in Hydrochloric Acid Solution at pH = 3

本文模拟了实际桥梁的腐蚀环境,使钢筋在受力的状态下进行锈蚀加速模拟试验(用加力架固定钢筋,用液压泵给钢筋试件预加力并做好防腐措施),采取线性极化法进行电化学检测。通过检测分析,初步揭示出受力钢筋的锈蚀度与力学性能退化规律之间的关系。试验结果表明:受力钢筋锈蚀试件的腐蚀速率大于非受力钢筋的锈蚀试件的腐蚀速率,预加力大的试件的腐蚀速率大于预加力小的试件。将锈蚀后的试件做力学性能测试,研究其屈服强度、极限强度的退化规律,并对钢筋的延性以及颈缩程度进行了仔细分析。测试结果表明:锈蚀试件的力学性能比非锈蚀试件的力学性能明显降低,其中,预加力大的试件的力学性能下降程度比预加力小的试件的力学性能下降程度要大得多。由此可见,采用受力钢筋得出的年腐蚀率及力学性能退化规律与实际桥梁情况更加相符合,可为桥梁耐久性预测提供更为准确的科学依据。

This paper simulates the corrosive environment of the actual bridge,so that the steel speeds up stimulated experiment of corrosion under the force(fixing the steel bar with the afterburner,pre-energizing the steel test piece with the hydraulic pump and taking anti-corrosion measures),taking the linear pole chemical method for electrochemical detection.Through the detection analysis,the relationship between the corrosion degree of the stressed steel bars and the degradation law of mechanical properties is revealed.The test result shows that the corrosion rate of the reinforced steel specimens is faster than that of the non-stressed steel reinforced specimens.The corrosion rate of the specimens with large pre-energization is also faster than that of the specimens with small pre-stress.The rusted test piece was tested for mechanical properties,and degradation law of yield strength and ultimate strength were studied,and the ductility and necking degree of steel bars were carefully analyzed.The test result shows that the mechanical properties of the rusted specimens are significantly reduced than those of the non-corrosive specimens.Among them,the mechanical properties of the specimens with large pre-stressing force leads to more shrinking than the mechanical properties of the specimens with less pre-energizing.It follows that the annual corrosion rate and mechanical property degradation law obtained by the stressed steel bar are more consistent with the real bridge condition,which can provide a more accurate scientific basis for the bridge durability prediction.