预应力锚固区FBG螺旋筋的研制  

Development of FBG spiral reinforcement in prestressed anchorage zone

作　　者：邓成伟 陶奇[3] 苏泳旗 朱万旭[1,2] DENG Chengwei;TAO Qi;SU Yongqi;ZHU Wanxu(College of Civil and Architectural Engineering,Guilin University of Technology,Guilin 541004,China;Guangxi Engineering Research Center of Intelligent Structural Material,Guilin University of Technology,Guilin 541004,China;China Railway Eryuan Engineering Group Co.,Ltd.,Chengdu 610031,China;Guangxi Hanximing Technology Co.,Ltd.,Guilin 541004,China)

机构地区：[1]桂林理工大学土木与建筑工程学院,广西桂林541004 [2]桂林理工大学广西壮族自治区智慧结构材料工程研究中心,广西桂林541004 [3]中铁二院工程集团有限责任公司,四川成都610031 [4]广西汉西鸣科技有限责任公司,广西桂林541004

出　　处：《中国测试》2024年第10期113-119,共7页China Measurement & Test

基　　金：国家自然科学基金项目(52068014);广西创新驱动发展专项项目(桂科AA 20302006)。

摘　　要：预应力锚固区的应力集中复杂,其承载和抗裂性能对预应力混凝土结构的安全耐久至关重要。针对锚固区应力应变检测难题,在其螺旋筋中径位置嵌入分布式的FBG,制备能可靠监测环向应变的FBG螺旋筋,并按国标GB/T 14370—2015对M15-9型锚具锚固区进行三组荷载传递试验。试验结果表明:FBG螺旋筋的全部测点均存活有效,能够全程跟踪锚固区应力变化;随着荷载的增加,其内部拉应变逐渐增大,在1.2倍极限荷载下实测出三个试件的螺旋筋实际最大拉应变分别为777.15、710.29、785.50με,其应力均未超过其材料屈服强度,螺旋筋尚处于弹性变形阶段。在0.6~0.8F_(ptk)加载过程中,试件侧表面开始出现竖向劈裂裂缝;1.0~1.2F_(ptk)加载过程中,首条裂缝均发展为主裂缝,同时加载端面出现斜裂缝,裂缝宽度最大值为0.15 mm,均满足规范要求。FBG螺旋筋应变传感器可为锚固区的服役期应力应变监测、预警及其设计方案提供一种有效手段。The stress concentration in the prestressed anchorage zone is complex,the bearing capacity and crack resistance of prestressed anchorage are vitally important for the safety and durability of prestressed concrete structure.Directing at the challenge of stress and strain detection in anchorage zone,distributed FBGs were embedded in the middle diameter of the spiral reinforcements to develop FBG spiral reinforcements,which could reliably monitor the circumferential strains.According to the national standard GB/T 14370—2015,three sets of load transfer tests were carried out on the anchorage zone of M15-9 anchorages.The test results show that all measuring points of the FBG spiral reinforcements are alive and effective,which can track the stress change of the anchorage zone in the whole process.The internal tensile strain of the FBG spiral reinforcements are increased gradually with load increasing.The actual maximum strains of the spiral reinforcements of the three sets are 777.15,710.29 and 785.50 με under 1.2 times of the ultimate load.The stresses do not exceed the yield strength of the material,and the spiral reinforcements are still in the elastic deformation stage.During the loading process of 0.6-0.8F_(ptk),the vertical split cracks appeared on the side surface of the specimens.During the loading process of 1.0-1.2F_(ptk),all the first cracks developed into the main crack on the surface,and oblique cracks appeared in the loading end surface.The maximum crack width is 0.15mm,all the cracks width meet the specification requirements.The FBG spiral reinforcement strain sensor can provide an effective means for the service period stress and strain monitoring,early warning and design scheme in anchorage zone.

关 键 词：预应力锚固区 FBG螺旋筋应变传感器 荷载传递试验 应力应变 竖向劈裂裂缝 

分 类 号：TB9[一般工业技术—计量学] TP212[机械工程—测试计量技术及仪器]