摘要
针对现有人行道板结构耐久性、安全性和舒适性不足等问题,提出一种预应力无腹筋预制超高性能混凝土(UHPC)人行道板。为明确新型预应力UHPC人行道板的破坏模式、承载力、刚度和延性等力学性能,开展UHPC人行道板足尺模型抗弯试验并通过ABAQUS软件进行有限元分析,对比UHPC人行道板有限元计算结果与试验结果并验证有限元模型的有效性,考察试验板预应力筋截面积和张拉预应力度等关键参数对试验板抗弯性能的影响。研究结果表明:预应力无腹筋UHPC人行道板破坏模式为弯曲破坏,跨中产生一条主裂缝,支座处板顶有少许裂缝但未发生破坏,开裂承载力富余40%,挠度仅为限值的14%,延性较好,安全系数高,板承载力和刚度均满足规范相应要求;预应力UHPC人行道板的开裂荷载比无预应力板提升28.68%~113.07%,增大预应力筋张拉应力可明显改善UHPC人行道板的抗裂性能,提高开裂后的刚度,降低板的屈服位移;同时,增大预应力筋截面直径可以有效提高结构屈服荷载和极限荷载,屈服荷载增幅13.37%~63.08%,极限荷载提升8.82%~57.96%,综合考虑经济效益和抗裂性能,建议UHPC人行道板采用直径为5 mm的预应力筋。新型预应力无腹筋预制超高性能混凝土人行道板有效提升了人行道板的力学性能,极大改善了传统人行道板的结构问题,满足实际工程的性能需求。
In order to crack the problems of durability,safety,and comfort of the existing pavement slab structure,a prestressed ultra-high performance concrete(UHPC)sidewalk slab without web reinforcement was proposed.To clarify the damage mode,bearing capacity,stiffness,ductility,and other mechanical properties of the new prestressed UHPC pavement slabs,the bending tests of the UHPC pavement slabs were carried out in full-scale model and the finite element analyses were carried out by using the ABAQUS software.To compare the finite element calculation results of UHPC pavement slabs with the test results and verify the validity of the finite element model,the influence of key parameters such as the cross-section area of prestressing tendons and the degree of tension prestressing on the flexural performance of the test slabs was investigated.The results are drawn as follows.The damage mode of the prestressed UHPC pavement slab without web is bending damage,with a main crack in the middle of the span.A little crack at the top of the slab at the support but no damage,the cracking capacity is 40%rich,and the deflection is only 14%of the limit value.The ductility is better,the safety coefficient is high,and the slab capacity and stiffness meet the corresponding requirements of the specification.The cracking load of the prestressed UHPC pavement slab increases by 28.68%~113%compared with that of the slab without prestressing.The cracking load of the prestressed UHPC pavement slab is 28.68%~113.07%higher than that of the non-prestressed slab.Increasing the tension stress of prestressing tendons can significantly improve the cracking resistance of the UHPC pavement slab,improve the stiffness after cracking,and reduce the yield displacement of the slab.At the same time,increasing the diameter of the prestressing tendon cross-section can effectively improve the yield load and ultimate load of the structure,with the increase of the yield load ranging from 13.37%to 63.08%,and the increase of the ultimate load ranging from 8.82%~57.96%.Taking into account the economic benefits and crack resistance,it is recommended that the UHPC pavement slabs use prestressing tendons with a diameter of 5 mm.Therefore,the new prestressed webless precast ultra-high performance concrete pavement slabs can effectively improve the mechanical properties of the pavement slabs,greatly improve the structural problems of the traditional pavement slabs,and meet the performance requirements of the actual project.
作者
杨金栋
张阳
傅玖志
唐浩
张杰
邱俊峰
YANG Jindong;ZHANG Yang;FU Jiuzhi;TANG Hao;ZHANG Jie;QIU Junfeng(Fujian Communications Planning&Design Institute Co.,Ltd.,Fuzhou 350004,China;College of Civil Engineering,Hunan University,Changsha 410082,China)
出处
《铁道科学与工程学报》
北大核心
2025年第5期2205-2217,共13页
Journal of Railway Science and Engineering
基金
国家自然科学基金资助项目(52378154)
福建省交通运输科技示范工程(SF20210101)
福建省住建行业科技项目(2022-K-208)。
关键词
人行道板
超高性能混凝土
模型试验
预应力
有限元分析.
sidewalk slab
ultra-high performance concrete
model test
prestress
finite element analysis
