UHPC-T梁抗弯疲劳性能试验研究及剩余承载能力评估  

Experimental Research on Bending Fatigue Performance of UHPC-T Beams and Evaluation of Their Residual Bearing Capacity

作　　者：朱琦 徐茂虎 叶力豪 蔡玮[1] 谢文[1] ZHU Qi;XU Maohu;YE Lihao;CAI Wei;XIE Wen(School of Civil&Environmental Engineering and Geography Science,Ningbo University,Ningbo 315211,China;China Construction Eighth Engineering Division Co.,Ltd.,Shanghai 200112,China;School of Civil Engineering,Jiangxi University of Engineering,Xinyu 338000,China)

机构地区：[1]宁波大学土木工程与地理环境学院,浙江宁波315211 [2]中国建筑第八工程局有限公司,上海200112 [3]江西工程学院土木工程学院,江西新余338000

出　　处：《工业建筑》2023年第11期131-138,共8页Industrial Construction

摘　　要：为了研究配筋率和预应力筋对UHPC-T梁抗弯疲劳性能及剩余承载能力的影响,以常规T梁为研究对象,设计并制作了6根UHPC-T梁与2根普通混凝土T梁,其中4根T梁进行三等分点抗弯疲劳试验,余下4根T梁进行三等分点抗弯静载试验,着重研究配筋率和预应力筋等因素对其挠度(残余挠度)、应变(残余应变)以及剩余承载能力等抗弯疲劳性能的影响。结果表明:增大配筋率和施加预应力对T梁混凝土疲劳应变影响较小,增大配筋率可有效降低钢筋疲劳应变,而施加预应力对钢筋疲劳应变影响不大;配筋率为0.372%和1.14%的UHPC-T梁及预应力UHPC-T梁疲劳试验后的剩余承载能力比相应的静载极限承载力分别下降了14.0%、6.7%和16.7%,表明疲劳荷载作用降低了其承载能力;当材料性能改善和配筋率增大时,UHPC-T梁的剩余承载力逐渐上升,相应的挠度及残余挠度降低;疲劳荷载作用下,施加预应力提升了T梁的剩余承载能力,减小了最大裂缝宽度。To study the influence of reinforcement ratio and prestressing tendon on the bending fatigue performance and residual bearing capacity of UHPC-T beams,six UHPC-T beams and two concrete T beams were designed and constructed.Four of the beams were subjected to three-point bending fatigue tests,while the other four beams were subjected to three-point bending static load tests,The impacts in order to study the influence of the reinforcement ratio and prestressing tendon on the deflection(residual deflection),strain(residual strain),and residual bearing capacity.were highlighted using the third point bending static load tests and fatigue tests,respectively.The results showed that increasing the reinforcement ratio and adding prestressing force had little effect on the concrete strain of the T beams based on a series of fatigue tests.Increasing the reinforcement ratio could reduce the rebar strain,whereas adding the prestressing tendon did not influence the rebar strain.The residual bearing capacity of the UHPC-T beams with 0.372%and 1.14%,and the prestressed UHPC-T beam decrease by 14.0%,6.7%,and 16.7%compared to the corresponding static ultimate bearing capacity,respectively.It was indicated that the fatigue load decreased the bearing capacity of UHPC-T beams.The residual bearing capacity of UHPC-T beams gradually increased with the increasing of reinforcement ratio increasing or the material performance,improving,and the corresponding deflection and residual deflection decreased.The prestressing force tendon application significantly improved the residual bearing capacity and mitigated the maximum crack width of UHPC-T beams under fatigue loads.

关 键 词：UHPC-T梁 配筋率 预应力筋 疲劳性能 剩余承载能力 

分 类 号：U441.4[建筑科学—桥梁与隧道工程]