Twist behavior of high-strength concrete hollow beams–Formation of plastic hinges along the length

2009 ◽  
Vol 31 (1) ◽  
pp. 138-149 ◽  
Author(s):  
S.M.R. Lopes ◽  
L.F.A. Bernardo
Keyword(s):  
High Strength Concrete ◽  
High Strength ◽  
Plastic Hinges ◽  
Strength Concrete ◽  
Hollow Beams

scholarly journals Experimental Study on the Torsional Behaviour of Prestressed HSC Hollow Beams

2020 ◽  
Vol 10 (2) ◽  
pp. 642 ◽  
Author(s):  
Luís Bernardo ◽  
Sérgio Lopes ◽  
Mafalda Teixeira
Keyword(s):  
Experimental Study ◽  
High Strength Concrete ◽  
Concrete Beams ◽  
Concrete Strength ◽  
High Strength ◽  
Experimental Program ◽  
Pure Torsion ◽  
Strength Concrete ◽  
Hollow Beams

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.

scholarly journals HIGH-STRENGTH CONCRETE HOLLOW BEAMS STRENGTHENED WITH EXTERNAL TRANSVERSAL STEEL REINFORCEMENT UNDER TORSION / SUKTINĖS STIPRIOJO BETONO DĖŽINIO SKERSPJŪVIO SIJOS, SUSTIPRINTOS IŠORINE PLIENINE SKERSINE ARMATŪRA

2011 ◽  
Vol 17 (3) ◽  
pp. 330-339 ◽  
Author(s):  
Luis F. A. Bernardo ◽  
Sergio M. R. Lopes
Keyword(s):  
High Strength Concrete ◽  
High Strength ◽  
Steel Reinforcement ◽  
Experimental Results ◽  
Pure Torsion ◽  
Strength Concrete ◽  
Box Beam ◽  
Torsion Moment ◽  
Hollow Beams ◽  
Transversal Reinforcement

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.

Study on Strength Development of High Strength Concrete Containing Alccofine and Fly-Ash

2012 ◽  
Vol 2 (3) ◽  
pp. 102-104 ◽  
Author(s):  
Suthar Sunil B ◽  
◽  
Dr. (Smt.) B. K. Shah Dr. (Smt.) B. K. Shah
Keyword(s):  
Fly Ash ◽  
High Strength Concrete ◽  
High Strength ◽  
Strength Development ◽  
Strength Concrete

Applications of High Strength Concrete for Highway Bridges

PCI Journal ◽  
1984 ◽  
Vol 29 (3) ◽  
pp. 44-73 ◽  
Author(s):  
Harold J. Jobse ◽  
Saad E. Moustafa
Keyword(s):  
High Strength Concrete ◽  
High Strength ◽  
Highway Bridges ◽  
Strength Concrete
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