摘要
对在现场破损桥面进行加固的基础上,采用高温蒸汽和常温养护的方法,对钢筋超高性能混凝土(UHPC)层加固成鳞破损桥面进行了抗弯试验。研究了正弯矩和负弯矩作用下RC-UHPC复合材料的抗裂性能、极限承载力、变形特征和破坏模式,结果表明:在受拉面设置UHPC后,复合材料的抗裂性能和极限承载力分别提高了2.5倍和2倍左右;而受压面超高强混凝土板的抗裂性能没有变化,极限承载力比完整混凝土板高30%。同时,钢筋混凝土板中钢筋的刚度也随拉应力的增大而明显增大,加固后各板的刚度均减小;超高延性和超高强混凝土的应变硬化特性抑制延缓了混凝土板中裂纹的扩展。依试验结果和破坏模式,建立了UHPC-RC板的开裂和极限抗弯承载力的解析表达式,对方程的适用性进行了验证,在某斜拉桥主梁破损桥面加固设计中得到了有效的应用。
Based on strengthening a damaged bridge deck in the field,this paper conducted flexural experiments on a scaled damaged bridge deck strengthened by reinforced ultrahigh performance concrete(UHPC)layer with high temperature steam and normal temperature curing;this paper investigates cracking capacity,ultimate capacity,deformation features and failure mode of RC-UHPC composites under positive bending moment and negative bending moment,respectively.Experimental results indicate that cracking and ultimate capacity of composites increased by about 2.5 and 2 times respectively with UHPC located at tension face comparing with intact RC slab;while for UHPC at compression face,no change in cracking capacity was observed and ultimate capacity was 30%higher than that of intact RC slab.Meanwhile,stiffness also obviously increased with tensile stress in steel reinforcement in RC slabs,decreasing after strengthening for all strengthened slabs;and propagation of cracks in RC slabs was restrained and delayed due to ultrahigh ductility and behavior of strain hardening of UHPC.Based on experimental results and failure mode,analytical equations for cracking and ultimate flexure capacity of UHPC-RC slabs were constructed,and applicability of equations was validated by some experimental results in this paper and other literature with good accuracy by predicted equations.Finally,the research achievements of this paper were effectively applied on the reinforcement design of damaged deck of main girder in a cable-stayed bridge.
作者
蒋维
JIANG Wei(Department of Civil&Environmental Engineering,Imperial College London,London SW72BX,UK)
出处
《粘接》
CAS
2022年第2期6-11,共6页
Adhesion
关键词
超高性能混凝土
受损钢筋混凝土(RC)
桥面
加强
弯曲性能
ultra high performance concrete
damaged reinforced concrete(RC)
bridge deck
strengthen
bending properties
