CFRP筋新型机械夹持-黏结型复合式锚具短期静力性能试验  

Short-term Performance of a Novel Mechanical-bond Composite Anchorage with CFRP Tendons

作　　者：梅葵花[1] 孙亚民[1,2,3] 孙晨然 孙胜江 任翔[2] MEI Kui-hua;SUN Ya-min;SUN Chen-ran;SUN Sheng-jiang;REN Xiang(School of Highway,Chang'an University,Xi'an 710064,Shaanxi,China;School of Architecture and Civil Engineering,Xi'an University of Science and Technology,Xi'an 710054,Shaanxi,China;Postdoctoral Research Station of Civil Engineering,Xi'an University of Science and Technology,Xi'an 710054,Shaanxi,China;North China Municipal Engineering Design and Research Institute Co.Ltd.,Tianjin 300202,China)

机构地区：[1]长安大学公路学院,陕西西安710064 [2]西安科技大学建筑与土木工程学院,陕西西安710054 [3]西安科技大学土木工程博士后流动站,陕西西安710054 [4]中国市政工程华北设计研究总院有限公司,天津300202

出　　处：《中国公路学报》2021年第1期66-78,共13页China Journal of Highway and Transport

基　　金：国家自然科学基金项目(51778059,51408484);中国博士后科学基金项目(2020M673608XB);陕西省重点研发项目(2018SF-359)。

摘　　要：为充分发挥CFRP筋高强轻质的特性,设计了一种新型机械夹持-黏结型复合式锚具,通过改变锚具的黏结长度、黏结介质倾角和黏结介质掺合料,以及是否设置夹片等参数,对6组锚具进行试验研究,测试CFRP筋新型锚具的极限荷载、荷载-滑移曲线、筋材应力和锚具钢套筒应力分布,分析不同参数对新型锚具锚固性能的影响规律,并与未设置夹片的对照组锚具进行比较,最后对3根CFRP筋材的复合式锚具锚固效果进行了试验验证。试验结果表明:新型锚具最终失效形式均表现为筋材破断破坏,且锚具锚固效率系数均满足规范规定的大于0.9的要求;筋材滑移量随着锚具黏结部分长度的增大而减小,合适的锚固长度宜为30~40倍筋材直径;锚具黏结部分倾角的减小会造成顶推力的减小,并造成锚具加载端与自由端滑移量差值增大;黏结介质中适度的掺砂量能够提升锚具的锚固性能,但当掺砂量超过一定程度时,将影响黏结介质本身的胶结性能,建议掺砂量不超过10%;无夹片组失效模式为筋材与胶体黏结滑移失效,锚固效率低,而新型复合式锚具由于顶推力的存在不仅能够减小锚具的整体滑移量,而且能够有效避免锚具在加载端的应力集中现象,极大改善锚具受力性能,提高锚具的锚固效率;该新型复合式锚具对多根CFRP筋材同样具有良好的锚固效果。In order to make full use of the advantages of high tensile strength and lightweight of CFRP tendons,a novel mechanical-bond composite anchorage was proposed and designed. By changing the anchoring length,the inclination of the grout,the dosage of additive in the grout,and by setting of clamps,the load carrying capacity,load-slip relationship,and stress of the CFRP tendon and steel sleeves of six groups of anchorages were tested to study the influences of different parameters on the anchoring performance. The anchoring performance of the novel composite anchorage was also compared with the referenced one,which had no clamps. The anchoring performance of this novel anchorage for three CFRP tendons was also tested. The test results show that all the novel composite anchorages fail with tendon rupture,and the anchoring efficiency is above 0. 9 and satisfies the code provision. The slip decreases with the anchoring length,with the optimal anchoring length for this novel composite anchorage being 30-40 times the diameter of the CFRP tendon. A decrease in the inclination of the grout results in a decrease in the pre-tightening force,thus leading to an increase in the difference of slips between the free and loaded ends. In addition,a moderate dosage of sand into the grout can improve the anchoring performance. However,a large dose of sand weakens the bond property of the grout and the anchoring performance. The proposed dosage of sand should not exceed 10%. Moreover,the referenced anchorage with no clamps fails with debonding between the CFRP tendon and the grout with a low anchoring efficiency. However,the novel composite anchorage can not only reduce the overall slip of the CFRP tendon but also avoid stress concentration at the loaded end. Thus,the anchoring performance is largely improved,and the load-carrying capacity is greatly enhanced. The test results also show that this novel anchorage can successfully grip multiple CFRP tendons.

关 键 词：桥梁工程 CFRP筋 试验研究 新型锚具 锚固性能 参数分析 荷载-滑移 

分 类 号：U443.38[建筑科学—桥梁与隧道工程]