锈蚀钢筋与钢纤维混凝土的黏结性能试验研究

发布时间：2018-01-06 04:01

本文关键词：锈蚀钢筋与钢纤维混凝土的黏结性能试验研究　出处：《建筑结构学报》2017年07期 　论文类型：期刊论文

【摘要】：钢纤维混凝土具有良好的开裂后拉伸性能和韧性,已被广泛用于工程结构的修复加固中。对于所修复的锈蚀构件,钢纤维混凝土与锈蚀钢筋的黏结性能是影响其力学性能的关键因素。首先通过电化学方法对钢筋进行预锈蚀,进而采用清理干净的预锈蚀钢筋制作拉拔试件,然后通过中心拉拔试验研究锈蚀钢筋与钢纤维混凝土的黏结性能。试验结果表明:钢纤维的掺入能够使试件从劈裂破坏转变为拔出破坏,同时黏结强度比提高4.4%~7.5%;随着黏结长度的减小,加载端与自由端的相对滑移也逐渐减小,而峰值黏结应力对应的平均滑移却逐渐增大;锈蚀率对黏结强度的影响与黏结长度相关,与未锈蚀试件相比,当锈蚀率达到约15%时,黏结长度为3d(d为钢筋直径)试件的黏结强度减小21%,而黏结长度为7d试件的黏结强度基本不变。基于试验结果,建立了以锈蚀率和黏结长度为参数的黏结强度经验公式,计算结果与试验结果吻合较好。
[Abstract]:Steel fiber reinforced concrete (SFRC) has been widely used in the repair and reinforcement of engineering structures because of its good tensile properties and toughness after cracking. The bonding property of steel fiber reinforced concrete and corroded steel bar is the key factor to affect its mechanical properties. Firstly, the steel bar is pre-corroded by electrochemical method, and then the clean pre-corroded steel bar is used to make drawing test piece. Then the adhesion properties of corroded steel bar and steel fiber concrete were studied by central drawing test. The results show that the steel fiber incorporation can change the specimen from split failure to pull-out failure. At the same time, the bond strength ratio increased by 4.4% and 7.5%; With the decrease of bonding length, the relative slippage between the loading end and the free end decreases gradually, while the average slip corresponding to the peak bonding stress increases gradually. The effect of corrosion rate on the bond strength is related to the bond length. When the corrosion rate reaches about 15, the bonding strength of the specimen is reduced by 21% when the corrosion rate is about 15. On the basis of the experimental results, an empirical formula for bond strength with corrosion rate and bond length as parameters is established, and the calculated results are in good agreement with the experimental results.
【作者单位】：河海大学海岸灾害及防护教育部重点实验室;浙江大学高性能建筑结构与材料研究所;
【基金】：国家自然科学基金项目(51408186) 江苏省自然科学基金项目(BK20140853) 水利部公益性行业科研专项(201501036)
【分类号】：TU375
【正文快照】： 0引言钢筋与混凝土之间良好的界面黏结是保证钢筋混凝土协同受力的基础。在碳化和氯盐侵蚀等外界环境作用下,导致混凝土内部的钢筋发生锈蚀,钢筋表面锈渣的润滑效应、钢筋肋纹的锈蚀损伤以及混凝土的锈胀裂缝等均会影响钢筋和混凝土之间的摩阻力和机械咬合力[1-3],从而导致其

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