考虑锈蚀预应力筋利用强度的PC梁受弯承载弯矩计算  

Calculation of flexural capacity of PC beams considering strength utilization of corroded prestressing tendon

作　　者：羊日华 戴理朝[1] 王磊 张建仁[1] YANG Rihua1,2,DAI Lizhao1,WANG Lei1,ZHANG Jianren1(1. School of Civil Engineering ＆ Architecture,Changsha University of Science ＆ Technology,Changsha 410114,China; 2. School of Civil Engineering,Hunan City University,Yiyang 413000,Chin)

机构地区：[1]长沙理工大学土木与建筑学院,湖南长沙410114 [2]湖南城市学院土木工程学院,湖南益阳413000

出　　处：《中南大学学报（自然科学版）》2018年第6期1526-1532,共7页Journal of Central South University:Science and Technology

基　　金：国家重点基础研究发展规划(973计划)项目(2015CB057705);国家自然科学基金资助项目(51678069);湖南省杰出青年基金资助项目(14JJ1022)~~

摘　　要：针对钢绞线锈蚀导致黏结性能下降造成预应力混凝土(PC)梁抗弯承载弯矩下降的问题,引入锈蚀影响因子研究锈蚀对预应力筋强度利用的影响,基于锈蚀PC梁静载试验,给出预应力筋强度利用率与锈蚀率的关系,进而建立锈蚀PC梁抗弯承载弯矩计算模型并进行验证。研究结果表明:PC梁抗弯承载弯矩随钢绞线锈蚀的增大而降低;在极限状态下,钢绞线屈服与配筋率和锈蚀程度有关,当配筋率小于0.23时,无论锈蚀与否,钢绞线均会屈服,当配筋率大于该临界值(0.23)时,需考虑锈蚀对钢绞线强度利用率的影响;建立的模型具有较高的精度,可以合理地预测钢绞线锈蚀对PC梁抗弯承载弯矩的影响。Considering that strand corrosion can reduce the bond strength and degrade the flexural capacity of prestressed concrete（PC） beam, a corrosion impact factor was introduced to calculate the strength utilization ratio of prestressing tendon under the ultimate load. The relationship between the strength utilization ratio and corrosion loss was proposed based on the loading test of eight corroded PC beams. Considering the strength utilization ratio of prestressing tendon,a model was proposed to predict the flexural capacity of corroded PC beams. The proposed model was verified.The results show that the flexural capacity of PC beams decreases with the increase of corrosion. The yield of prestressing tendon in the ultimate state depends on the reinforcement index and corrosion degree. The corroded strand can yield when the reinforcement index is less than 0.23. For the large reinforcement index, the effect of corrosion on the strength utilization coefficient of the corroded strand should be considered. The proposed model considering the strength utilization coefficient of strand can significantly predict the flexural capacity of corroded PC beams.

关 键 词：预应力混凝土梁 钢绞线锈蚀 配筋率 强度利用率 抗弯承载弯矩 

分 类 号：TU375[建筑科学—结构工程]