偏心受拉作用下预应力CFRP筋-型钢混凝土构件抗裂试验  

Experiment on crack resistance of prestressed CFRP tendons-steel reinforced concrete members under eccentric tension

作　　者：张鹏[1] 桂金洋 邓宇[1] 沈民合 孙飞 赵晓冬 ZHANG Peng;GUI Jinyang;DENG Yu;SHEN Minhe;SUN Fei;ZHAO Xiaodong(College of Civil Engineering and Architecture,Guangxi University of Science and Technology,Liuzhou 545006,China)

机构地区：[1]广西科技大学土木建筑工程学院,柳州545006

出　　处：《复合材料学报》2021年第3期920-931,共12页Acta Materiae Compositae Sinica

基　　金：国家自然科学基金(51768008);中国博士后科学基金(2017M613273XB);广西自然科学基金(2019JJA160137)。

摘　　要：为解决我国型钢混凝土桁架转换层拉杆及低层角柱在正常使用阶段易出现大面积拉裂缝的问题,以轻质高强、防腐的碳纤维增强树脂复合材料(CFRP)筋为预应力筋,提出可有效控制裂缝的预应力CFRP筋-型钢混凝土结构体系,并对其偏心受拉作用下的抗裂性能进行系统研究。以预应力水平、偏心距、纵筋直径及型钢翼缘厚度为主要参数制作11个构件,通过自行研发的拉-压转换桁架实现偏拉加载。结果表明:引入CFRP筋后CFRP筋-型钢混凝土构件抗裂度大幅提升,相较于普通偏拉构件,预应力大偏拉构件开裂荷载提高了64.8%~102.3%,预应力小偏拉构件提高了61.7%~117%,其抗裂性能与预应力水平、纵筋直径和型钢翼缘厚度正相关,与偏心距负相关。参照组合结构设计规范,提出构件开裂阶段中和轴的三种位置分布,并推导出开裂荷载公式,与试验值比较吻合度较高,可为其他复合材料筋在预应力偏拉体系的应用提供参考。In our country,there are many eccentric tension members,such as steel reinforced concrete truss transfer layer straining beam,low-rise building corner column.For these members,large-scale cracks easily appear during normal use stage.Aiming at these problems,this paper took the light,high-strength and anti-corrosion carbon fiber reinforced polymer composite(CFRP)tendons as the prestressed reinforcement,the prestressed CFRP-steel reinforced concrete structure system was designed by combining CFRP tendons with prestressed steel reinforced concrete,which can effectively restrain the crack.And on this basis,a systematic study on the crack resistance under eccentric tension was carried out.A total of eleven members were designed and fabricated with the prestress level,eccentricity,longitudinal reinforcement diameter and profile flange thickness as the main parameters,and eccentric loading was achieved through the self-developed tension-compression conversion truss system.The results indicate that the crack resistance of the prestressed CFRP tendons-steel/concrete members is greatly strengthened.Compared with the ordinary eccentric members,the cracking loads of the large tension members with prestressed CFRP tendons are increased by 64.8%–102.3%,the cracking loads of the small tension members with prestressed CFRP tendons are increased by 61.7%–117%.The crack resistance of the member is positively related to the prestress level,longitudinal reinforcement diameter and steel flange thickness,and negatively related to the eccentricity.With reference to the combined structural design specification,three positions of the neutral axis of the prestressed CFRP tendons-steel reinforced concrete members during the cracking stage are proposed,and the calculation formula of cracking load is derived.Compared with the test value,the agreement is perfect,which can provide a reference for the application of other composites in the prestressed eccentric tension system.

关 键 词：预应力 碳纤维增强树脂复合材料(CFRP)筋 型钢混凝土构件 抗裂性能 开裂荷载计算 

分 类 号：TU398.903[建筑科学—结构工程] TU317.1