UHPC加固锈蚀钢筋混凝土柱轴心受压性能试验研究  

Experimental study on the performance of UHPC reinforced corroded reinforced concrete column under axial compression

作　　者：周建庭[1,2] 王蔚丞 杨俊[1,2] 王宗山 徐安祺 ZHOU Jianting;WANG Weicheng;YANG Jun;WANG Zongshan;XU Anqi(School of Civil Engineering,Chongqing Jiaotong University,Chongqing 400074,China;State Key Laboratory of Mountain Bridges and Tunnels Jointly Built by Province and Ministry,Chongqing Jiaotong University,Chongqing 400074,China)

机构地区：[1]重庆交通大学土木工程学院,重庆400074 [2]重庆交通大学省部共建山区桥梁及隧道国家重点实验室,重庆400074

出　　处：《混凝土》2021年第12期44-50,共7页Concrete

基　　金：中国工程院咨询研究项目(2019-CQ-ZD-4);国家自然科学基金青年基金项目(51908093);重庆市自然科学基金创新群体科学基金(cstc2019jcyj-cxttX0004);贵州省交通运输厅科技项目(2018-123-001)。

摘　　要：为研究在轴压荷载作用下,UHPC对锈蚀钢筋混凝土柱加固前后的裂缝开展情况、破坏形态、竖向和横向变形、极限荷载的影响,共设计了9根试件,通过电化学的方式对所有试件通电锈蚀,再采用UHPC对部分试件加固,最后采用控制变量法分别对锈蚀率为10%、20%、30%的试验柱进行轴压破坏试验研究。试验结果表明:钢筋混凝土柱的表观裂缝随锈蚀率提高逐渐发展,UHPC可以有效的抑制锈蚀裂缝的开展,采用UHPC加固后不会对原RC柱产生围压作用;未加固试件破坏形态主要表现为试验柱表面出现大量裂缝后混凝土被压碎,加固后试验柱破坏形态主要表现为UHPC加固层劈裂破坏;加固后构件极限压应变值平均提高了24.8%,极限拉应变值平均提高了34.1%,极限承载力约为原试验柱的2倍;对UHPC加固锈蚀RC柱进行了理论模型验证,考虑了核心约束区混凝土强度的增强、锈蚀后混凝土的有效截面面积、锈蚀钢筋屈服强度的折减系数等,研究结果表明该理论模型与实测值较为符合。在考虑核心约束区混凝土强度的增强、锈蚀后混凝土的有效截面面积、锈蚀钢筋屈服强度的折减系数的基础上,提出了UHPC加固锈蚀RC柱的理论模型,理论值与实测值符合较好,可供实际工程参考。A total of 9 specimens were designed to study the influence of UHPC on crack development,failure modes,vertical and horizontal deformation,and ultimate load of corroded reinforced concrete columns before and after reinforcement under axial compressive loads.Firstly,all specimens are electrochemically corroded with electricity,then UHPC is used to reinforce some specimens,and finally,the control variable method is used to conduct axial compression failure test research on test columns with corrosion rate of 10%,20%and 30%respectively.The test results show that the apparent cracks of reinforced concrete columns develop gradually with the increase of corrosion rate,and UHPC can effectively restrain the development of corrosion cracks,and the reinforcement with UHPC will not produce confining pressure on the original RC columns.The failure modes of unreinforced specimens mainly show that the concrete is crushed after a large number of cracks appear on the surface of the test column,and the failure modes of the test column after reinforcement mainly show the splitting failure of the UHPC reinforcement layer.After the reinforcement,the ultimate compressive strain value and ultimate tensile strain value of the members increased by 24.8%and 34.1%on average,and the ultimate bearing capacity was about twice that of the original test column.The theoretical model of UHPC reinforced corroded RC column is verified,and the enhancement of concrete strength in the core confined area,effective section area of corroded concrete and reduction coefficient of yield strength of corroded reinforcement are considered.On the basis of the enhancement of concrete strength in core confined area,effective section area of corroded concrete and reduction coefficient of yield strength of corroded steel bar,a theoretical model for UHPC reinforcement of corroded RC column is proposed.

关 键 词：桥梁工程 UHPC 加固 锈蚀 极限承载力 

分 类 号：TU528.01[建筑科学—建筑技术科学]