摘要
为解决传统大尺寸盖梁在装配化施工时需要拆分为2到3段分别吊装,导致制约施工效率且盖梁顶部易开裂的问题,提出了2种新型的装配式高性能混凝土盖梁结构形式:超高性能混凝土(UHPC)+工程用水泥基复合材料(ECC)盖梁方案和全ECC盖梁方案。首先,结合某实际工程背景,应用UHPC,ECC等新材料,给出了上述2种新型盖梁形式对应的结构设计方案。然后,利用杆系数值分析方法,建立了各盖梁方案的计算模型,以普通预应力混凝土盖梁为对照组,对提出的各盖梁方案的受力性能进行了检验与分析。对上述各盖梁方案及之前研究提出的钢-UHPC组合盖梁方案展开了自重、截面尺寸、预应力钢筋数量、制造材料成本等方面的对比分析,给出了各盖梁方案的适用性。结果表明:用UHPC替代普通混凝土可显著改善盖梁的受力性能,并且减小盖梁的截面,降低盖梁的自重;在盖梁顶部采用ECC可避免验算裂缝宽度,降低对预应力的需求,从而实现简化构造及降低成本的目的;钢-UHPC组合盖梁方案可实现最小的吊装重量。综上所述,引入UHPC,ECC等高性能混凝土材料能够在保证受力性能及抗裂性能的前提下显著降低盖梁自重,提升其装配化施工效率;提出的2种装配式高性能混凝土盖梁方案可行有效,为盖梁设计提供了新的选择。
In order to solve the problem that the traditional large-size cap beam needs to be split into 2 or 3 segments to be hoisted separately during assembly construction,lead to restrict construction efficiency and the top concrete is easy to crack,2 new types of prefabricated high-performance concrete cap beam structure,ultra-high performance concrete(UHPC)+engineered cementitious composites(ECC)cap beam scheme and full ECC cap beam scheme,are proposed.First,on the background of a practical engineering,the structural schemes of the above 2 new cap forms are proposed with new the materials such as UHPC and ECC.Then,the calculation models of different cap beam schemes is established by using the bar system numerical analysis method.Taking the ordinary prestressed concrete cap beam as the control group,the mechanical properties of the proposed cap beam schemes are tested and analyzed.The self-weights,cross-sectional dimensions,numbers of prestressed reinforcement and the costs of manufacturing materials of different cap beam schemes and the steel-UHPC composite cap beam scheme proposed before are compared and analyzed,and the applicability of different cap beam schemes is given.The result shows that(1)the replacement of ordinary concrete with UHPC can significantly improve the mechanical properties of the cap beam,reduce the cross-section of the cap beam and reduce the weight of the cap beam;(2)the use of ECC at the top of the cap beam can avoid checking the crack width and reduce the demand for prestress,so as to simplify the structure and reduce the cost;(3)steel-UHPC composite cap beam scheme can can achieve the minimum hoisting weight.In summary,using high performance concrete such as UHPC and ECC can significantly reduce the dead weight of cap beam and enhance the construction efficiency significantly on the premise of ensuring the mechanical performance and crack resistance.The proposed 2 schemes of prefabricated high-performance concrete cap beam are feasible and effective,which provide the new choice for cap beam design.
作者
张志明
朱尧于
方明
ZHANG Zhi-ming;ZHU Yao-yu;FANG Ming(Guangzhou Highway Engineering Group Co.,Ltd.,Guangzhou Guangdong 510075,China;CCCC Highway Bridges National Engineering Research Centre Co.,Ltd.,Beijing 100088,China)
出处
《公路交通科技》
CAS
CSCD
北大核心
2023年第2期64-71,共8页
Journal of Highway and Transportation Research and Development
基金
广东省重点领域研发计划项目(2019B111105002)。
关键词
桥梁工程
高性能混凝土盖梁
数值分析
装配式结构
方案对比
bridge engineering
high-performance concrete cap beam
numerical analysis
prefabricated structure
scheme comparison
