摘要
铁路钢桥面板防水、防腐要求极高,为制备满足铁路钢桥面铺装性能要求的超高性能混凝土(UHPC),以浩吉铁路洞庭湖大桥为背景,根据UHPC流变性能与施工性能要求,优选UHPC配合比,研究优选的UHPC抗渗性能与微结构特征,并在实桥上进行UHPC铺装应用。结果表明:UHPC流变性能变化特征符合Herschel-Bulkley模型,降粘剂能改善UHPC流变性能,使UHPC的屈服应力接近100 Pa,塑性粘度接近70 Pa·s,进而提升了施工性能;优选的UHPC微结构致密,钢纤维与基体结合紧密,抗水渗透和抗氯离子渗透性能良好;通过自动化摊铺设备可实现UHPC高质量铺装,采用完善的保湿养护措施使得UHPC表面无裂纹,效果良好。
As the waterproof and corrosion protection requirements for railway steel bridge deck are very critical,the ultra-high performance concrete(UHPC)has increasingly been an option to address this issue.In the Dongting Lake Bridge of Haolebaoji-Ji′an Railway,the UHPC that owns superior impermeability and microstructure is applied to the deck pavement,which was prepared considering the rheological properties and constructability of UHPC,with modified mixing proportion.The engineering practice proves that the rheological properties of the UHPC prepared conform to the Herschel-Bulkley model,the viscosity reducer can upgrade the rheological properties of the UHPC and allow the yielding stress and plastic viscosity of UHPC to be near 100 Pa and 70 Pa·s,respectively,thereby enhancing the constructability of the UHPC.The UHPC prepared also has compact microstructure,in which the steel fibers and matrix are closely combined,resulting in good waterproof ability and chloride ion impermeability.The utilization of automatic paving equipment ensured the high-quality placement of UHPC,and the effective moisturizing and curing measures were taken to prevent the occurrence of surficial cracks and improve the quality of UHPC pavement.
作者
许斌
童欢
陈露一
XU Bin;TONG Huan;CHEN Lu-yi(China Railway Major Bridge Engineering Group Co.,Ltd.,Wuhan 430050,China;School of Civil Engineering,Architecture and Environment,Hubei University of Technology,Wuhan 430068,China;China Railway Britech Co.,Ltd.,Wuhan 430034,China;State Key Laboratory for Health and Safety of Bridge Structures,Wuhan 430034,China)
出处
《世界桥梁》
北大核心
2022年第3期87-93,共7页
World Bridges
基金
湖北省科技厅创新发展项目(2021BLB155)
中国中铁股份有限公司科技研究开发计划项目(2019-重大-05)。
关键词
铁路桥
钢桥面板
桥面铺装
超高性能混凝土
流变性能
施工性能
抗渗性能
工程应用
railway bridge
steel bridge deck
deck pavement
ultra-high performance concrete
rheological property
constructability
impermeability
engineering practice
