旧有输电铁塔混凝土基础主柱老化损伤修复研究

发布时间：2018-04-17 06:23

本文选题：输电铁塔 + 基础主柱　；参考：《中国矿业大学》2017年硕士论文

【摘要】：旧有高压输电线路(如运行25年以上)的部分铁塔混凝土基础主柱因长期受自然环境的侵蚀而产生老化损伤,使得其承载性能和耐久性能大幅降低。针对不同损伤程度的铁塔基础主柱,本文提出建议采用修复剂修复和增大截面加固两种修复方法,并对两种修复方法的修复效果进行了试验研究。对徐州地区运行的500kV典型输电线路铁塔混凝土基础主柱进行检测,分析了铁塔基础主柱的损伤原因及机理。对不同龄期的混凝土试块涂抹修复剂后的抗压强度和碳化深度进行了试验研究,分析了龄期、混凝土强度等因素对混凝土抗压强度修复效果及混凝土抗碳化性能影响作用的影响规律。结果表明,修复剂对混凝土抗压强度的修复效果随着龄期的增长呈现出先增强后减弱的规律,龄期28d时,修复效果最佳;修复剂对混凝土抗碳化性能的影响作用随着龄期的增长基本呈现出逐渐减弱的规律。对涂抹修复剂后的低强混凝土短柱试件极限承载力进行了试验研究,分析了修复剂用量、混凝土强度等因素对短柱试件承载性能修复效果的影响规律。结果表明,修复剂对低强混凝土短柱试件承载性能的修复效果随着修复剂用量的增加而不断增强。对短柱试件增大截面加固后的轴心受压及双向偏心受压极限承载力进行了试验研究,分析了加固厚度、加固材料强度、双向偏心偏心距等因素对试件加固后轴心受压及双向偏心受压承载性能的影响规律。结果表明,加固厚度增加可大幅提高试件加固后轴心受压承载性能;加固材料强度增大可提高试件加固后轴心受压承载性能,但加固材料强度与原试件强度相差较大时,试件加固后轴心受压承载性能提高效果不增反减;试件加固后双向偏心受压承载性能随偏心距的增大而降低。提出了增大截面加固后的试件双向偏心受压极限承载力的计算公式,并结合试验结果对公式的正确性进行了分析。结果表明:本文提出的公式基本可用,可为加固方案设计及工程应用提供参考。
[Abstract]:The aging damage caused by the erosion of the old high voltage transmission lines (such as more than 25 years operation) of the main column of the concrete foundation of the iron tower caused by the erosion of the natural environment for a long time, the bearing capacity and durability of the tower can be greatly reduced.Aiming at the main column of tower foundation with different damage degree, this paper puts forward two kinds of restoration methods, that is, repairing agent and strengthening with enlarged section, and carries on the experimental research on the restoration effect of two kinds of repair methods.The main column of concrete foundation of typical 500kV transmission line in Xuzhou area is tested, and the damage cause and mechanism of main column of tower foundation are analyzed.The compressive strength and carbonation depth of concrete samples of different ages after smearing the repair agent were studied, and the age of concrete was analyzed.The influence of concrete strength and other factors on the effect of compressive strength repair and carbonation resistance of concrete.The results show that the repair effect of the repairable agent on the compressive strength of concrete increases firstly and then weakens with the increase of age, and the best effect is at the age of 28 days.The effect of the repair agent on the carbonation resistance of concrete is gradually weakened with the increase of age.The ultimate bearing capacity of low strength concrete short column specimens coated with repairable agent is studied experimentally. The influence of the amount of repair agent and the strength of concrete on the repair effect of short column specimens is analyzed.The results show that the effect of the repairable agent on the load-bearing performance of the low strength concrete short column specimens is enhanced with the increase of the amount of the repairable agent.The ultimate bearing capacity of axial compression and biaxial eccentricity compression of short column specimens strengthened with increased cross-section is studied experimentally. The strengthening thickness and strength of strengthening materials are analyzed.The influence of biaxial eccentricity and other factors on axial compression and biaxial eccentric bearing capacity of specimens strengthened.The results show that the axial compression bearing capacity of the specimens can be greatly improved with the increase of the strengthening thickness, and the axial compression bearing capacity of the specimens can be improved with the increase of the strength of the strengthening materials, but when the strength of the strengthening materials is different from the strength of the original specimens,After strengthening, the bearing capacity of axial center is not increased but decreased, and the biaxial eccentric bearing capacity decreases with the increase of eccentricity.A formula for calculating the ultimate bearing capacity of biaxial eccentric compression of reinforced specimens with increased cross-section is proposed, and the correctness of the formula is analyzed in combination with the experimental results.The results show that the formula presented in this paper can be used as a reference for the design of reinforcement scheme and engineering application.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU755.7

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