EXPERIMENTAL RESEARCH ON MECHANICAL PROPERTIES OF NEW AND OLD CONCRETE JOINTS OF PREFABRICATED STRUCTURE
-
摘要: 装配式桥梁结构中,由于既有的预制桥墩与承台间的承插式连接方式,接缝界面无钢筋穿过,存在黏结性能不足的问题。为此,提出一种新型界面连接形式,即界面预埋分布式钢纤维的连接技术。为研究此新型接缝对新旧混凝土界面黏结性能的影响,分别设计双面剪切试验和轴心拉伸试验,制定6种试验工况,包括素混凝土整体浇筑、钢筋混凝土整体浇筑、C40-C40界面凿毛连接、UHPC-C40界面凿毛连接、UHPC-C40界面预埋波浪型或端钩型钢纤维连接,测试界面的抗剪、抗拉承载力。结果表明:界面预埋钢纤维连接试件的抗剪承载力较凿毛处理和素混凝土整体浇筑有显著提高,最高达到钢筋混凝土整体浇筑的86.5%;预埋钢纤维连接试件的抗拉承载力也明显提高,试件受拉破坏时UHPC-C40界面没有开裂。所得结果初步验证了超高性能混凝土-普通混凝土(UHPC-NC)新旧界面预埋分布式钢纤维工艺可行,并且可有效提高接缝的抗剪强度和抗拉强度。Abstract: In the prefabricated bridge structure, the existing socket connection between the prefabricated pier and the bearing platform has no reinforcement passing through the joint interface, which has the problem of insufficient bond performance. In the paper, a new type of interface connection was proposed, namely the interface embedded distributed steel fiber connection technique. In order to study the influence of this new type of joint on the bond performance of new and old concrete interface, double-sided shear test and axial tensile test were designed respectively, and six test conditions were formulated, including integral pouring of plain concrete, integral pouring of reinforced concrete, chiseled connection of C40-C40 interface, chiseled connection of UHPC-C40 interface, embedded wave-shaped/end-hook-shaped steel fiber connection of UHPC-C40 interface, and the shear and tensile capacity of the interface were tested. The results showed that the shear bearing capacity of the steel fiber connection specimen was significantly higher than that of the chiseling treatment and the whole pouring of plain concrete, which is up to 86.5% of the whole pouring of reinforced concrete; the tensile bearing capacity of the steel fiber connection specimen was also significantly improved, and the UHPC-C40 interface was not cracked when the specimen was broken. In this paper, the feasibility of embedded distributed steel fiber technique for UHPC-NC new and old interface was preliminarily verified, and the shear strength and tensile strength of the joint could be effectively improved.
-
Key words:
- prefabricated structure /
- UHPC-NC interface /
- embedded steel fiber /
- interfacial adhesion
-
HARALDSSON O S, JANES T M,EBERHARD M O, et al. Seismic Resistance of Socket Connection Between Footing and Precast Column[J]. Journal of Bridge Engineering, 2013, 18(9):910-919. 耿佳硕.采用UHPC现浇湿接缝连接的装配式桥墩抗震性能研究[D].郑州:郑州大学,2019. BU Z Y, WU W Y. Inter Shear Transfer of Unbounded Prestressing Precast Segmental Bridge Column Dry Joints[J]. Engineering Structures, 2018, 154(1):52-65. 陈金彪.装配式桥梁预制空心桥墩与承台连接的研究与应用[D].合肥:合肥工业大学,2019. MARSH M L, STRINGER S J, STANTON J F, et al. Precast Bent System for High Seismic Regions:FHWA-HIF-13-037[R]. Washington D.C.:Federal Highway Administration, 2013. HARALDLSSON O S, JANES T M,EBERHARD M O,et al. Precast Bent System for High Seismic Regions:Laboratory Tests of Column-to-Footing Socket Connections[J].Bridge Construction, 2013. DOI: 10.21949/1506041. 刘国梁. RPC/NC粘结试件的收缩性能研究[D]. 北京:北京交通大学,2018. WANG B, SHI L, LIU F, et al. Evaluation of Tensile Bonding Strength Between UHTCC Repair Materials and Concrete Substrate[J]. Construction and Building Materials, 2016,112:595-606. 王孟伟. ECC与既有混凝土粘结性能的影响因素研究[D].南京:东南大学,2018. DIAB A M, ELMOATY A E M A, ELDIN M R T. Slant Shear Bond Strength Between Self Compacting Concrete and Old Concrete[J]. Construction and Building Materials, 2016, 130:73-82. TAZARV M, SAIIDI M S. UHPC-Filled Duct Connections for Accelerated Bridge Construction of RC Columns in High Seismic Zones[J]. Engineering Structures, 2015, 99(15):413-422. TAZARV M, SAIIDI M S. Design and Construction of UHPC-filled Duct Connections for Precast Bridge Columns in High Seismic Zones[J]. Structure and Infrastructure Engineering, 2016,13(6):1-11. HUSSEIN, HUSAM H. Interfacial Properties of Ultrahigh-Performance Concrete and High-Strength Concrete Bridge Connections[J]. Journal of Materials in Civil Engineering, 2016, 28(5). DOI: 10.1061/(ASCE)MT.1943-5533.0001456. BASSAM A, TAYEH B H, ABU B. Mechanical and Permeability Properties of the Interface Between Normal Concrete Substrate and Ultra High Performance Fiber Concrete Overlay[J].Construction and Building Materials, 2012, 36:538-548. CARBONELL M A. Bond Performance Between Ultrahigh-Performance Concrete and Normal-Strength Concrete[J]. Journal of Materials in Civil Engineering, 2014, 26(8). DOI: 10.1061/(ASCE)MT.1943-5533.0000890. 吴香国, 张孝臣. 预制超高性能混凝土修复层与既有混凝土界面黏结短期性能研究[J]. 建筑结构学报, 2018, 39(10):156-163. 苏庆田, 胡一鸣, 田乐, 等.用于组合梁桥面板湿接缝的弧形钢筋连接构造[J]. 中国公路学报, 2017, 30(9):86-92. ZHAO C, WANG K, ZHOU Q, et al. Full-Scale Test and Simulation on Flexural Behavior of Dovetail-Shaped Reactive Powder-Concrete Wet Joint in a Composite Deck System[J]. Journal of Bridge Engineering, 2018, 23(8). DOI: 10.1061/(ASCE)BE.1943-5592.0001265. PAN W H, FAN J S, NIE J G, et al. Experimental Study on Tensile Behavior of Wet Joints in a Prefabricated Composite Deck System Composed of Orthotropic Steel Deck and Ultrathin Reactive-Powder Concrete Layer[J]. Journal of Bridge Engineering, 2016, 21(10). DOI: 10.1061/(ASCE)BE.1943-5592.0000935. 王景全, 王震, 高玉峰, 等. 预制桥墩体系抗震性能研究进展:新材料, 新理念, 新应用[J]. 工程力学, 2019, 36(3):1-23. SONG P S, HWANG S. Mechanical Properties of High-Strength Steel Fiber-Reinforced Concrete[J]. Construction and Building Materials, 2004, 18(9):669-673. 张正先. 配有钢筋的新旧混混凝土界面连接试验研究[J]. 华南理工大学学报(自然科学版), 2002(10):98-102.
点击查看大图
计量
- 文章访问数: 222
- HTML全文浏览量: 43
- PDF下载量: 11
- 被引次数: 0