中低加载速率下BFRP筋-混凝土粘结性能研究  

STUDY ON BOND BEHAVIOR OF BFRP BARS AND CONCRETE UNDER MEDIUM AND LOW LOADING RATES

作　　者：袁鹏 陈万祥 郭志昆 王英杰 范鹏贤 YUAN Peng;CHEN Wan-xiang;GUO Zhi-kun;WANG Ying-jie;FAN Peng-xian(State Key Laboratory of Disaster Prevention and Mitigation of Explosion and Impact,PLA Army Engineering University,Nanjing,Jiangsu 210007,China;School of Civil Engineering,Sun Yat-sen University,Zhuhai,Guangdong 519082,China;Southern Marine Science and Engineering Guangdong Laboratory,Zhuhai,Guangdong 519082,China)

机构地区：[1]陆军工程大学爆炸冲击防灾减灾国家重点实验室,江苏南京210007 [2]中山大学土木工程学院,广东珠海519082 [3]南方海洋科学与工程广东省实验室,广东珠海519082

出　　处：《工程力学》2021年第5期131-142,共12页Engineering Mechanics

基　　金：国家自然科学基金项目(51578541,51979280)。

摘　　要：BFRP(basalt fiber reinforced polymer)筋是一种取代钢筋用于土木工程领域的新型纤维复合材料,中低加载速率下BFRP筋-混凝土粘结性能是保证其协同作用承受动荷载的重要前提。该文根据正交试验方法设计了16组粘结试件,利用MTS试验系统对不同加载速率(0.005 mm/s~5 mm/s)下的BFRP筋-混凝土试件进行了中心拉拔试验,研究了加载速率、混凝土强度及BFRP筋直径等因素对粘结性能的影响。在现有粘结强度计算模型的基础上,对粘结特征参数进行了修正,提出了中低加载速率下的BFRP筋-混凝土动态粘结强度计算公式,进一步建立了BFRP筋-混凝土粘结滑移本构关系模型。结果表明:BFRP筋-混凝土粘结试件主要发生拔出破坏与劈裂破坏,粘结滑移过程可分为滑移段、下降段和残余段;粘结强度随加载速率和混凝土强度的增大而增大,而随纤维筋直径的增大却显著减小;理论计算结果与试验结果吻合良好,为预测中低加载速率下BFRP筋-混凝土粘结性能提供了一种有效手段。BFRP bar is a new type of fiber composite material used in civil engineering field instead of steel bar.The bonding performance of BFRP bars and concrete under medium and low loading rates is an important premise to ensure the joint action of BFRP bars and concrete under dynamic loading.16 groups of bonding specimens are designed according to the orthogonal test method,and the pull-out test is carried out on the BFRP bar-concrete specimens under different loading rates(0.005 mm/s-5 mm/s)by using the MTS test system,and the influence of loading rate,of concrete strength and of the diameter of BFRP bars on the bonding performance is studied.Based on the existing calculation model for bond strength,the bond characteristic parameters are modified,a formula is proposed for calculating the dynamic bond strength of BFRP bars and concrete under medium and low loading rates,and the bond-slip constitutive relationship model is further established for BFRP bars and concrete.The results show that the specimens fail due to the pull-out failure or the splitting failure,and bond stress-slip curves can be divided into a sliding stage,a declining stage and a residual stage.The bond strength increases with the increase of loading rate and of concrete strength,but decreases significantly with the increase of the diameter of BFRP bars.The theoretical calculation results are in good agreement with the experimental results,which provides an effective method for predicting the bonding properties of BFRP bars and concrete under medium and low loading rates.

关 键 词：混凝土 BFRP筋 拉拔试验 粘结性能 本构关系 

分 类 号：TU528.572[建筑科学—建筑技术科学]