摘要
现行植筋技术规程要求植筋过程应确保植筋孔干燥、无灰尘,但并非所有工程都能保证植筋条件达到规范要求。为研究植筋安装条件能否影响植筋锚固性能,参照欧洲的建筑紧固件锚栓规范ETAG 001设计植筋胶适用性试验,包括清孔效果试验和孔洞淹水试验。设计植筋直径为12mm和20mm,锚固深度为10d、15d和20d(d为植筋直径)的18组植筋拉拔试件,通过拉拔试验探究钢筋直径、锚固深度及植筋安装条件等因素对植筋锚固性能的影响。试验过程中测量植筋的应变及荷载-位移曲线。试验结果表明:安装条件对无机植筋锚固性能造成不同程度的影响。锚固深度为10d时适用性试验组的极限拉拔荷载最小约为对照组的54.90%,且破坏形式由混合破坏转变为钢筋拔出破坏;随着锚固深度的增加,安装条件对植筋锚固性能的影响逐渐减小,当深度达到20d时,适用性试验组的极限拉拔荷载与对照组相差小于10%。通过拉拔试验过程中钢筋应变的测量和计算,可知植筋试件在拉拔试验过程中粘结应力分布是不均匀的,粘结应力峰值靠近植筋加载段且峰值大小约为其他测点的1.5倍;此外,安装条件对不同试验组粘结应力的分布影响较小。
In the current technical regulations for rebar planting,it is required that the rebar planting process should ensure that the rebar planting hole is dry and free of dust,but not all projects can ensure that the rebar planting conditions meet the specification requirements.In order to study whether the installation conditions of the planting bar can affect the anchorage performance of the planting bar,the applicability test of the planting bar glue with reference to the European standard ETAG 001 for anchor bolts for construction fasteners was designed,including the hole cleaning effect test and the hole flooding test.The effects of anchoring performance affected by planting bar diameters,anchoring depths and installation conditions are explored through pull-off test,18 groups of planting bar pull-out specimens are designed with planting bar diameters of 12mm and 20mm and anchoring depths of 10d,15d and 20d(d is the diameter of the planting bar).The strain and load-displacement curves of the planting bars were measured during the test.The test results show that the installation conditions have different degrees of influence on the anchorage performance of inorganic planting bars.When the anchoring depth is 10d,the minimum ultimate pull-out load of the suitability test group is about 5490%of that of the control group,and the failure mode changes from mixed failure to steel pull-out failure.As anchoring depths increase,the influence of anchoring performance affected by installation conditions gradually decreases.When the depth reaches 20d,the difference between the ultimate tensile load of the suitability test group and the control test group is less than 10%.Through the measurement and calculation of reinforcement strain during the pull-out test,it can be seen that the distribution of bonding stress of the embedded bar specimen during the pull-out test is uneven.The peak value of bonding stress is close to the loading section of the embedded bar,and the peak value is about 15 times that of the other measuring point
作者
陈大川
刘冉
彭勃
CHEN Dachuan;LIU Ran;PENG Bo(College of Civil Engineering,Hunan University,Changsha 410082,China;Hunan Gutebang Civil Engineering Development Co.,Ltd.,Changsha 410205,China)
出处
《建筑结构》
北大核心
2024年第14期153-158,152,共7页
Building Structure
基金
国家自然科学基金资助项目(50778067)。
关键词
结构加固
无机植筋胶
拉拔试验
锚固性能
reinforcement of engineering structure
inorganic rebar planting glue
pull-out test
anchorage performance
