复合材料科学与工程 ›› 2024, Vol. 0 ›› Issue (5): 66-75.DOI: 10.19936/j.cnki.2096-8000.20240528.010

• 应用研究 • 上一篇    下一篇

CFRP-PCPs复合筋加固钢-混组合梁负弯矩区抗裂试验与理论计算

邓宇, 凌道远*, 倪淼   

  1. 广西科技大学 土木建筑工程学院,柳州545006
  • 收稿日期:2023-05-25 出版日期:2024-05-28 发布日期:2024-06-17
  • 通讯作者: 凌道远(1999—)男,硕士研究生,研究方向为预应力型钢混凝土组合结构,2401968039@qq.com。
  • 作者简介:邓宇(1978—),男,博士(后),教授,研究方向为新型复合材料及预应力混凝土结构。
  • 基金资助:
    国家自然科学基金资助项目(52268021,52168016);广西自然科学基金项目(2019GXNSFAA245061)

Experimental and theoretical calculation of cracking resistance in the negative moment zone of steel concrete composite beams strengthened with CFRP-PCPs composite reinforcement

DENG Yu, LING Daoyuan*, NI Miao   

  1. College of Civil Engineering and Architecture, Guangxi University of Science and Technology, Liuzhou 545006, China
  • Received:2023-05-25 Online:2024-05-28 Published:2024-06-17

摘要: 为解决钢-混组合梁负弯矩区混凝土板易开裂而造成刚度减弱的行业难题,以预制的CFRP-PCPs(carbon fibre reinforced polymer-prestressed concrete prisms)复合筋作为中支座的腹筋,并以复合筋的数量、预应力张拉水平和截面尺寸为主要参数设计制作了五根复合筋钢-混组合连续梁和一根普通组合连续梁,研究其在单跨单点荷载下负弯矩区的抗裂性能。结果表明:复合筋能显著增强中支座截面刚度,对负弯矩区的裂缝控制能力提升显著;与普通组合梁相比,复合筋梁的开裂荷载提高近30%,裂缝数量与裂缝宽度减少近50%;复合筋面积是提高裂缝控制能力的主要因素,预应力水平和截面尺寸对开裂荷载的影响较弱;复合筋的开裂荷载与预应力水平、面积正相关,其中预应力水平是影响复合筋效用时长的关键因素。基于现有理论和试验数据,本文提出CFRP-PCPs复合筋钢-混组合梁负弯矩区开裂荷载和复合筋的开裂荷载计算公式,计算结果与试验值较为吻合,可为复合筋在钢-混组合梁桥实际工程中应用提供参考。

关键词: CFRP-PCPs复合筋, 钢-混组合梁, 负弯矩区, 抗裂性能, 复合材料

Abstract: In order to overcome the industry problem that the concrete slab in the negative moment region of the steel-concrete composite beam is prone to cracking causing weakening of stiffness. Prefabricated CFRP-PCPs (carbon fiber reinforced polymer-prestressed concrete prisms) composite reinforcement is used as the web reinforcement of the middle support. Five steel-concrete composite continuous beams with composite reinforcement and one ordinary composite continuous beam are designed and manufactured with the number of composite reinforcement, prestressed tension level and section size as the main parameters, the crack resistance in the negative moment zone under single-span single-point load is studied. The results show that: The composite reinforcement can significantly enhance the section stiffness of the middle support, the crack control ability in the negative bending moment zone is significantly improved; compared with ordinary composite beams, the cracking load of composite reinforcement beams is increased by nearly 30%, the number and width of cracks are reduced by nearly 50%; the area of composite reinforcement is the main factor to improve the crack control ability, the influence of prestress level and section size on cracking load is weak; the cracking load of composite reinforcement is positively related to the level and area of prestress. Among them, the level of prestress is the key factor affecting the effective duration of composite reinforcement. Based on the existing theoretical and experimental data, in this paper, the calculation formulas of the cracking load in the negative moment region of the steel-concrete composite continuous beam with CFRP-PCPs composite reinforcement and the cracking load of the composite reinforcement are proposed, the calculated results are in good agreement with the test values, it can provide reference for the practical engineering application of composite reinforcement in steel-concrete composite beam bridges.

Key words: CFRP-PCPs composite reinforcement, steel-concrete composite beam, negative moment region, crack resistance, composites

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