scholarly journals Numeric Analysis on Shear Behavior of High-Strength Concrete Single-Keyed Dry Joints with Fixing Imperfections in Precast Concrete Segmental Bridges

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2914 ◽  
Author(s):  
Haibo Jiang ◽  
Mingzhu Chen ◽  
Zhijun Sha ◽  
Jie Xiao ◽  
Jiahui Feng

Fixing imperfections in keyed dry joints between the concrete segments compromise the performance of precast concrete segmental bridges (PCSBs), which needs to consider carefully. In this study, a finite-element model on high-strength concrete single-keyed dry joints in PCSBs was established and validated by experimental results. Parametric studies on fixing imperfections in key, concrete strengths, and confining pressures were carried out based on that model. The numeric results included crack patterns, load–displacements and shear strength. Fixing imperfections—especially at lower surface of keys—reduced shear strength of single-keyed dry joints by the different shear transfer mechanism. Higher confining pressure and concrete strength improved the shear strength, but they mitigated and aggravated the effect of fixing imperfections at lower surface of key on shear strength, respectively. Compared with simulating results, AASHTO standard overestimated the shear capacity of single-keyed dry joints with fixing imperfections at lower surface of key by up to 0.602–22.0%, but greatly underestimated that of the rest. A modified formula with a strength reduction factor was proposed. For six experimental three-keyed dry-joint specimens and 30 numeric single-keyed dry-joint specimens with or without fixing imperfections, the average ratio of code predictions to experimental results was 90.4% and 81.6%, respectively.

2005 ◽  
Vol 8 (2) ◽  
pp. 101-116 ◽  
Author(s):  
Sumei Zhang ◽  
Lanhui Guo ◽  
Zaili Ye ◽  
Yuyin Wang

This paper presents an experimental study of the separated behavior of short ( L/H=3) high strength concrete-filled rectangular hollow section (RHS) tubes concentrically loaded in compression to failure. A total of 50 specimens were tested. Experimental results showed that the concrete strength influenced the failure pattern of the specimen. The height-to-breadth ratio of the rectangular tube (varying from 1.0 to 1.6) had no evident influence on the ultimate bearing capacity of the specimen. Then based on the experimental results, a numerical separation method was successfully used to separate the compressive load carried by the steel tube and the core concrete. The equivalent One-Dimensional nonlinear stress-strain models of the steel and the confined concrete were suggested, which can be used to determine the overall behavior of the high strength concrete-filled RHS tubes. The stress-strain models have been used to numerically analyze the behavior of high strength concrete-filled RHS tubes. The numerical results are compared with the experimental results and they agreed well with each other.


2012 ◽  
Vol 166-169 ◽  
pp. 3298-3301
Author(s):  
Shan Suo Zheng ◽  
Xie Han ◽  
Qing Lin Tao ◽  
Wei Wang

Based on the tests of 5 steel reinforced high strength concrete (SRHSC) frame interior joint specimens, this paper discusses the mechanism of load transference in the joints. Shear effect of each part of the joints including concrete, steel web, band, flange frame and stirrup is analyzed. And then, the shear capacity equation of SRHSC frame joints is presented. Comparing the calculation results with the test results, it is indicated that the shear capacity equation proposed can correctly evaluate the ultimate shear strength for SRHSC joints.


2016 ◽  
Vol 22 (5) ◽  
pp. 1019-1038 ◽  
Author(s):  
Haibo Jiang ◽  
Ying Chen ◽  
Airong Liu ◽  
Tianlong Wang ◽  
Zhuangcheng Fang

2008 ◽  
Vol 400-402 ◽  
pp. 857-863
Author(s):  
Wei Jian Yi ◽  
Yan Mei Lv

19 RC beams with shear span-to-depth equal to 3 were tested under a stiff testing facility, and complete load-deflection curves including the post-peak branch were obtained. Based on the test results the effects of concrete strength, stirrups strength, inclined stirrup angle, the amount of longitudinal reinforcement on failure mode, shear ductility index and shear capacity were analyzed. The test results were compared with the shear design approaches of Chinese Code and American Code. The results indicate that the shear failure of beam with appropriate web reinforcement has finite ductility. High-strength concrete beams with high-strength stirrups can increase not only the shear capacity, but also the shear ductility. The shear capacity of beams with high-strength concrete and stirrup can be designed with Chinese Code, but shear capacity of high-strength concrete beams without stirrups, or with the smaller amount of longitudinal reinforcement, and normal strength concrete beams with high-strength stirrups may be over-estimated by the Code.


Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3345
Author(s):  
Fangwen Wu ◽  
Shuo Liu ◽  
Chengfeng Xue ◽  
Kangkang Yang ◽  
Yanpeng Feng ◽  
...  

Perfobond rib (PBL) shear connectors, made up of the perforated steel plates with the penetrating rebars passing through the holes, are extensively adopted in steel-concrete composite structures for their excellent performance. The adequate understanding of mechanical properties for PBL connectors is of great significance for their reasonable design. In this study, a push out experiment, including 12 specimens with the parameters of concrete strength, diameter of penetrating rebars and the number of holes on perforated steel plate, was performed to explore the mechanical behavior of PBL connectors with steel fiber high strength concrete (SFHSC). The experimental results showed that the shear capacity of the PBL connectors increased with the increase in concrete strength, diameter of the penetrating rebars and the number of holes. Furthermore, a general prediction formula for the shear capacity of PBL connectors was developed, which considers the shear contribution of concrete dowels, concrete end-bearing, interfacial bonding between the perforated steel plates and concrete and the penetrating rebars as well as the enhancement effect of steel fibers. The prediction results of the equation are in good agreement with the experimental data and could provide a reference for the design of PBL connectors.


2020 ◽  
Vol 10 (2) ◽  
pp. 642 ◽  
Author(s):  
Luís Bernardo ◽  
Sérgio Lopes ◽  
Mafalda Teixeira

This article describes an experimental program developed to study the influence of longitudinal prestress on the behaviour of high-strength concrete hollow beams under pure torsion. The pre-cracking, the post-cracking and the ultimate behaviour are analysed. Three tests were carried out on large hollow high-strength concrete beams with similar concrete strength. The variable studied was the level of longitudinal uniform prestress. Some important conclusions on different aspects of the beams’ behaviour are presented. These conclusions, considered important for the design of box bridges, include the influence of the level of prestress in the cracking and ultimate behaviour.


2011 ◽  
Vol 17 (3) ◽  
pp. 330-339 ◽  
Author(s):  
Luis F. A. Bernardo ◽  
Sergio M. R. Lopes

Some bridges have to withstand high levels of torsion forces. As a consequence, box type beams are often the obvious solution. It could be possible that the balance of transversal to longitudinal torsion reinforcement is not fully reached. If the transversal reinforcement is somehow underestimated, the box beam needs to be transversally strengthened. From the various solutions, external transversal reinforcement is certainly one possibility. The investigation presented here aimed to study such solution. The authors tested four hollow beams under pure torsion. The level of the non balanced ratio between internal longitudinal and transversal torsion reinforcement was one of the parameters that were considered in this investigation. Other parameter was the existence or the no existence of external transversal strengthening reinforcement. The experimental results of the tests have shown the effectiveness of the use of the external transversal strengthening steel reinforcement to compensate the lack of balance of internal transversal to longitudinal torsion reinforcement with respect to various behaviour aspects, such as: increasing of torque strength, increasing of ductility, increasing of cracking torsion moment, and better distribution of cracking. Santrauka Kai kurie tiltai turi atlaikyti dideles sukimo jėgas. Tam tikslui dažnai naudojamos dėžinio skerspjūvio sijos. Gali būti, kad tarp sukimui atlaikyti naudojamos skersinės ir išilginės armatūros ne visada pasiekiamas tinkamas balansas. Jei skersinė sija armuota nepakankamai, dėžinio skerspjūvio sijas gali tekti papildomai stiprinti. Vienas iš įvairių galimų stiprinimo variantų – armavimas išorine skersine armatūra. Šiame straipsnyje pateikiama tokio stiprinimo analizė. Autoriai išbandė keturias grynojo sukimo veikiamas dėžinio skerspjūvio sijas. Vienas iš tyrimo parametrų – skersinės ir išilginės sukimo armatūrų santykio nesubalansuotumo lygis. Kitas parametras – išorinės skersinės stiprinimo armatūros buvimas arba nebuvimas. Eksperimentinių tyrimų rezultatai parodė stiprinti naudojamos išorinės plieninės skersinės armatūros veiksmingumą, kompensuojant vidinės skersinės ir išilginės suktinės armatūrų tarpusavio nesubalansuotumą. Efektyvumas buvo įrodytas tokias aspektais: padidėjusi sukamoji galia ir elastingumas, padidėjęs plyšių atsiradimo sukimo momentas bei geresnis plyšių pasiskirstymas.


2003 ◽  
pp. 75-91
Author(s):  
Motoyuki SUZUKI ◽  
Mitsuyoshi AKIYAMA ◽  
Wei Lun WANG ◽  
Masayoshi SATO ◽  
Naomi MAEDA ◽  
...  

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