基于开裂混凝土箱梁挠度变化分析其氯盐腐蚀情况  

Chloride Corrosion Analysis of Cracked Concrete Box Girder Based on Its Deflection Variation

作　　者：李昭辉 LI Zhao-hui(Gansu Gonghanglu Road Industry Co.,Ltd.,Lanzhou,Gansu,730000,China)

机构地区：[1]甘肃公航旅路业有限公司,甘肃兰州730000

出　　处：《建材技术与应用》2024年第4期23-26,共4页Research and Application of Building Materials

摘　　要：氯盐的侵蚀作用会加速混凝土梁体中钢筋的锈蚀,而裂缝会加速Cl-的入侵速率,从而使钢筋锈蚀提前和进程加快。通过长期浸泡法对开裂的缩尺混凝土箱梁进行氯盐腐蚀加载研究其有效承载截面的变化;采用三分点加载试验对浸泡试验梁施加荷载,研究荷载与氯盐腐蚀联合作用下的挠度变化情况。基于点蚀不均匀系数的计算得到箱梁抗弯惯性矩与点蚀坑深度的关系,结合力学分析得到氯盐环境下混凝土箱梁的荷载-挠度曲线,并与试验结果进行对比。研究结果表明:理论计算值与试验结果具有较高的吻合度;在计算腐蚀后的截面特性时,可忽略锈蚀钢筋截面面积的影响;在施工过程中可减少施工裂缝和减缓钢筋接触氯盐来减小氯盐的影响。The corrosion effect of chlorine salts will accelerate the corrosion of steel bars in the concrete beam body,and the crack will accelerate the invasion rate of Cl-,which will advance the corrosion of steel bars and accelerate the process.The chloride corrosion loading was carried out on the cracked scale concrete box girder by long-term immersion method,and the change of effective bearing section of concrete box girder was studied.The three-point loading test was used to apply load to the immersion test beam,and the deflection change under the combined action of load and chloride corrosion was studied.Based on the calculation method of pitting non-uniformity coefficient,the relationship between bending inertia moment and pitting pit depth of box girder was obtained.Combined with mechanical analysis,the load-deflection curve of concrete box girder under chloride environment was obtained and compared with the test results.The results show that the theoretical calculation values are in good agreement with the experimental results.When calculating the cross-sectional characteristics after corrosion,the cross-sectional area of corroded steel bars should be ignored.In the construction process,two methods of reducing construction cracks and slowing down the contact of steel bars with chloride salt can be used to reduce the influence of chloride salt corrosion.

关 键 词：氯盐侵蚀 挠度 惯性矩 点蚀坑 施工措施 

分 类 号：TU528.01[建筑科学—建筑技术科学]