化学植筋黏结性能的抗冻性试验研究

Experimental study on the anti-freezing property of bonding of chemical steel bar fixation

混凝土化学植筋是工程界广泛应用的一种后锚固连接技术。有关混凝土等单一材料的抗冻性能研究及试验方法已较成熟,但对混凝土植筋系统特别是黏结界面的抗冻性研究国内外均极少见。本文分析了混凝土、胶粘剂等材料的抗冻性能,提出植筋与混凝土的黏结抗冻性试验方案。根据混凝土植筋黏结受力特点设计了两组试件:金属套筒植筋试件和混凝土立方体植筋试件。试件经历50次冻融循环后,进行轴向拉拔试验,并将拉拔试验结果与自然状态下养护的同类拉拔试验结果进行对比。结果表明,植筋系统黏结界面具有与混凝土和胶粘剂相一致的抗冻性能,混凝土化学植筋经历50次冻融循环后其拉拔承载力基本不变。

Chemical adhesive steel bar in concrete is a post-installation fixing technique widely used in engineering. Although there are many studies on the anti-freezing behavior of materials such as concrete, study on the durability of chemical steel bar fixing system, especially the interface bonding durability, is insufficient. After analyzing the anti- freezing behaviors of concrete and adhesive, respectively, a test method is proposed. According to the bonding performance of adhesive bars in concrete, two groups of specimens are designed： metal tube specimen and concrete cubic specimen. After 50 cycles of freezing and thawing, pull-out test are performed. The pull-out test results are compared with those of similar specimens prepared in natural atmosphere. The result indicates that chemical adhesive fixing may keep the antifreezing performance of concrete and adhesive. The pull-out capacity of chemical adhesive steel bars in concrete would not decrease much, after 50 cycles of freezing and thawing.