摘要
为解决钢-混凝土组合连续梁负弯矩区桥面板的开裂问题,提出了采用超高性能混凝土(UHPC)代替负弯矩区桥面板的部分普通混凝土(NC),利用UHPC超高的力学性能解决负弯矩区桥面板的开裂问题,对其抗裂性能进行研究;设计并完成了3片钢-UHPC组合梁负弯矩区抗裂试验,获得开裂荷载、跨中位移、裂缝宽度和应变等试验数据。结合国内外裂缝宽度计算公式,提出了简易的适用于钢-UHPC组合梁的桥面板裂缝宽度计算公式,并根据已有钢-UHPC组合梁文献的裂缝宽度试验数据,验证了提出的桥面板裂缝宽度计算公式的可靠性和适用性。结果表明:UHPC能提高组合梁负弯矩区的开裂荷载,具有抑制桥面板裂缝发展的能力,能明显提高桥面板负弯矩区的抗裂性能,有效解决负弯矩区桥面板的开裂问题;根据试验结果计算的名义应力均大于工程实际设计值,负弯矩区采用UHPC代替NC的结构具有优异的抗裂性能;建议组合梁负弯矩区UHPC纵向铺设长度宜为0.2L~0.25L(L为计算跨径),铺设厚度宜为60~70 mm。
In order to solve the cracking problem of bridge deck slab in the negative bending moment zone of steel-concrete continuous girders,it was proposed to use ultra-high performance concrete(UHPC)to replace part of normal concrete(NC)of bridge deck slab in the negative bending moment zone.The ultra-high mechanical property of UHPC was used to solve the cracking problem of bridge deck slab in the negative bending moment zone,and its crack resistance was studied.Three steel-UHPC composite beams were designed and tested for crack resistance in the negative bending moment zone,obtaining experimental data on crack load,mid-span displacement,crack width,and strain.A simple formula for calculating the crack width of bridge deck slab suitable for steel-UHPC composite beams was proposed based on domestic and foreign crack width calculation formulas.The reliability and applicability of the proposed formula for calculating the crack width of bridge deck slab were verified based on crack width test data from existing literature on steel-UHPC composite beams.The results show that UHPC can increase the cracking load in the negative bending moment zone of composite beams,and has the ability to suppress the development of cracks in bridge decks,which can significantly improve the crack resistance of bridge deck slab in the negative bending moment zone and effectively solve the cracking problem of bridge deck slab in the negative bending moment zone.The nominal stresses calculated based on the experimental results are all greater than the actual design values of the project,indicating that the structure using UHPC instead of NC in the negative bending moment zone has excellent crack resistance performance.It is recommended that the longitudinal laying length of UHPC in the negative bending moment zone of composite beams should be 0.2 L-0.25L(L is the calculated span)and the laying thickness should be 60-70 mm.
作者
李立峰
彭浩
邹德强
黄心仪
李凌霄
LI Lifeng;PENG Hao;ZOU Deqiang;HUANG Xinyi;LI Lingxiao(College of Civil Engineering,Hunan University,Changsha 410082,Hunan,China;China Construction Fifth Engineering Bureau Co.,Ltd.,Changsha 410004,Hunan,China)
出处
《建筑科学与工程学报》
北大核心
2025年第3期15-25,共11页
Journal of Architecture and Civil Engineering
基金
国家自然科学基金项目(51978257,52278176)
中建五局科技研发计划项目(cscec5b-2020-17)。
作者简介
李立峰(1971-),男,工学博士,教授,博士生导师,E-mail:lilifeng@hnu.edu.cn。
