首页|体外预应力节段式UHPC无腹筋梁抗剪性能试验研究

体外预应力节段式UHPC无腹筋梁抗剪性能试验研究

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体外预应力节段式超高性能混凝土(UHPC)无腹筋桥梁由于其施工工业化水平高且构造简单,得到广泛地关注,但其抗剪性能研究尚不成熟,相关规范也相对滞后.为了研究体外预应力节段式UHPC无腹筋梁的抗剪性能,开展了静力破坏试验,共制作了 5 根体外预应力节段式UHPC无腹筋梁、2 根体外预应力节段式UHPC有腹筋梁和 1根体外预应力整体式UHPC无腹筋梁,选取了剪跨比、钢纤维掺量、箍筋间距为研究参数进行试验.结果表明:接缝张开后梁刚度明显下降;添加钢纤维的试验梁的裂缝多而密;钢纤维的掺入可以提高梁的开裂强度、极限强度和裂后性能,2%钢纤维掺量的梁开裂强度比 1.5%和 0%掺量的增大 8.20%和 1.16 倍;配箍筋的梁在钢纤维失效后箍筋开始受力,并且很快达到屈服,箍筋的存在可以提高梁极限承载力,无腹筋梁的极限承载力比箍筋间距为 150 mm和 75 mm的梁低 15.9%和 19.6%.采用AASHTO GSCB INTERIM-2003 标准中计算干接缝节段式梁的折减系数 0.85.在不考虑安全系数的情况下,法国规范NF P 18-710 中UHPC梁抗剪承载力计算公式可以准确地预测含钢纤维体外预应力节段式UHPC无腹筋梁的抗剪强度,其试验值和预测值比值的平均值为 1.04,标准差为 0.28.
Experimental Study on Shear Behavior of Externally Prestressed Segmental UHPC Beam without Stirrup
Externally prestressed segmental UHPC beams without stirrups has attracted extensive attention because of its high level of construction industrialization and simple structures,but its shear performance study is not mature and the standards update stagnantly.In order to study the shear performance of segmental UHPC beams without stirrups,5 externally prestressed segmental UHPC beams without stirrups,2 externally prestressed segmental UHPC beams with stirrups and 1 externally prestressed monolithic UHPC beam without stirrups are fabricated.The shear-to-depth ratio,steel fiber content and stirrup spacing are selected as the research parameters.The result shows that(1)the stiffness of the beam decreases obviously after the joint is opened;(2)there are many and dense cracks in the test beam with steel fiber;(3)the crack strength,ultimate strength and post-crack performance of the beams can be improved by steel fiber addition,the cracking strength of beams with 2%steel fiber content is 8.20%and 1.16 times higher than that of beams with 1.5%and 0%steel fiber contents;(4)the stirrup begins to bear force after the steel fiber fails,and soon reaches yield,the existence of stirrup can improve the ultimate bearing capacity of the beam,the ultimate bearing capacity of beams without stirrup is 15.9%and 19.6%lower than that of beams with stirrup spacing of 150 mm and 75 mm.The AASHTO GSCB INTERIM-2003 standard is used to calculate the reduction factor of 0.85 for the dry-jointed segmental beams.With no consideration for safety factor,the formula for calculating the shear capacity of UHPC beams in French standard NF P 18-710 can accurately predict the shear strength of externally prestressed segmental UHPC beams without stirrup,the average value of the ratio of experimental value to predicted value is 1.04,and the standard deviation is 0.28.

bridge engineeringshear behaviorfour-point loadingultra-high performance concrete(UHPC)beam without stirrupprecast segmental beam

姜海波、胡泽彬、曹志鹏、田月强、孙向东

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广东工业大学 土木与交通工程学院,广东 广州 510006

中路杜拉国际工程股份有限公司,广东 广州 510627

广东省交通规划设计研究院集团股份有限公司,广东 广州 510507

桥梁工程 抗剪性能 四点加载 超高性能混凝土(UHPC) 无腹筋梁 预制节段梁

国家自然科学基金广东省自然科学基金广州市科技规划项目

517781502016A030313699201804010422

2024

10.3969/j.issn.1002-0268.2024.02.011

公路交通科技
交通运输部公路科学研究院

公路交通科技

CSTPCD北大核心
影响因子：1.007
ISSN：1002-0268
年,卷(期)：2024.41(2)
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