Assessment of shear capacity of prestressed concrete members with insufficient web reinforcement using AASHTO LRFD general shear design method

2021 ◽  
Vol 242 ◽  
pp. 112530
Author(s):  
Jongkwon Choi ◽  
Jarrod Zaborac ◽  
Oguzhan Bayrak
Keyword(s):  
Prestressed Concrete ◽  
Design Method ◽  
Shear Capacity ◽  
Concrete Members ◽  
Shear Design ◽  
Web Reinforcement ◽  
Aashto Lrfd

Background to the general method of shear design in the 1994 CSA-A23.3 standard

1999 ◽  
Vol 26 (6) ◽  
pp. 827-839 ◽  
Author(s):  
Khaldoun N Rahal ◽  
Michael P Collins
Keyword(s):  
Prestressed Concrete ◽  
Structural Design ◽  
Design Method ◽  
Bending Moment ◽  
Shear Capacity ◽  
Shear Design ◽  
Standard Design ◽  
Modified Compression Field Theory ◽  
Compression Field ◽  
General Method

The 1994 CSA-A23.3 standard "Design of concrete structures" includes a new shear design method based on the equations of the modified compression field theory (MCFT). This "general method" is a simplification which casts the MCFT in the traditional "Vc + Vs" format resulting in a set of six general equations and two tables. This new method unifies the treatment of reinforced, partially prestressed and fully prestressed concrete and accounts, in a rational manner, for the effects of axial load and bending moment on shear capacity. Simplifying the MCFT while maintaining acceptable generality and accuracy involved a number of considerations and assumptions. This paper gives the background to the development of these shear design equations and tables of the general method.Key words: beams, building codes, crack width and spacing, diagonal cracking, reinforced concrete, shear strength, size effect in shear, structural design.

Einheitliches Querkraftmodell für Stahl- und Spannbetonbrücken – erweiterte Grundlagen/Uniform Shear Design Method for Existing Reinforced and Prestressed Concrete Bridges – Extended Background

Bauingenieur ◽  
2016 ◽  
Vol 91 (12) ◽  
pp. 487-495
Author(s):  
Martin Herbrand ◽  
Martin Classen ◽  
Alexander Stark ◽  
Dominik Kueres
Keyword(s):  
Prestressed Concrete ◽  
Design Method ◽  
Concrete Bridges ◽  
Prestressed Concrete Bridges ◽  
Shear Design ◽  
Uniform Shear

Während das Biegetragverhalten von Stahl- und Spannbetonbauteilen als gelöst angesehen wird, ist das Querkrafttragverhalten schubschlanker Bauteile nicht abschließend geklärt. Vor allem für die Beurteilung von Bestandsbauwerken sind aber Querkraftmodelle notwendig, die möglichst einfach anwendbar sind und dennoch ausreichend genaue und damit wirtschaftliche Vorhersagen der Tragfähigkeit erlauben. Ein einheitliches Querkraftmodell mit Betontraganteil für Stahl- und Spannbetonbauteile ermöglicht bei der Bemessung einen stetigen Übergang zwischen Bauteilen ohne und mit Querkraftbewehrung, wenn deren Betontraganteile für asw = 0 identisch sind. Der Vergleich mit den ACI-DAfStb-Querkraftdatenbanken belegt, dass ein solches Modell für Bauteile mit Querkraftbewehrung zu deutlich geringeren Streuungen und gleichzeitig einem höheren Sicherheitsniveau im Vergleich zum aktuellen EC2 führt. Insbesondere für Bauteile mit geringen Querkraftbewehrungsgraden ergeben sich hierdurch höhere rechnerische Tragfähigkeiten, was zum Beispiel für die Nachrechnung von Bestandsbauwerken wie Brücken von Vorteil ist. In diesem Beitrag werden die Hintergründe für einen konsistenten Übergang von einen Fachwerkmodell mit Betontraganteil zu einem Fachwerkmodell mit variabler Druckstrebenneigung erläutert.

Design method for checking tensile stresses under service loads in cracked prestressed concrete members with 2,400‐MPa strands

2019 ◽  
Vol 29 (1) ◽  
Author(s):  
Hyo‐Eun Joo ◽  
Sun‐Jin Han ◽  
Deuckhang Lee ◽  
Hyunjin Ju ◽  
Soo‐Yeon Seo ◽  
...  
Keyword(s):  
Prestressed Concrete ◽  
Design Method ◽  
Tensile Stresses ◽  
Concrete Members

scholarly journals Analytical study on creep shear failures of RC slender beams without web reinforcement

2018 ◽  
Vol 195 ◽  
pp. 02010
Author(s):  
Halwan Alfisa Saifullah ◽  
Kenichiro Nakarai ◽  
Nobuhiro Chijiwa ◽  
Koichi Maekawa
Keyword(s):  
Shear Failure ◽  
Concrete Structures ◽  
Reduction Factor ◽  
Shear Capacity ◽  
Sustained Load ◽  
Shear Cracks ◽  
Shear Design ◽  
Web Reinforcement ◽  
Slender Beams ◽  
Shear Failures

Sustained load problems, which can cause excessive deformation and severe damage to concrete structures, have been considered in current worldwide design codes by applying reduction factors on the compressive and tensile strength of concrete. A reduction factor in the shear design may also be required due to the decrease of shear-transfer action corresponding to the increases of the shear cracks opening. However, only a few studies are examining the effect of creep on shear performance of concrete structures, and the results are still inconclusive. As a complement to the previous experimental works, this study aims to investigate the effect of loading rate on the shear capacity of RC slender beams by non-linear finite element (FE) analysis. A spaceaveraged constitutive model with fixed multi-directional cracks was employed in the simulation of diagonal shear failure. The present study analytically examines the time-dependent effects on the beams under different loading rates until the delayed failure and compares the results with the previous experimental ones.

Shear Behavior of CFRP Prestressed Concrete Beams without Stirrups

2011 ◽  
Vol 266 ◽  
pp. 126-129 ◽  
Author(s):  
Zuo Hu Wang ◽  
Xiu Li Du ◽  
Jing Bo Liu
Keyword(s):  
Prestressed Concrete ◽  
Failure Modes ◽  
Shear Failure ◽  
Concrete Beams ◽  
Shear Behavior ◽  
Shear Capacity ◽  
Shear Span ◽  
Compression Failure ◽  
Concrete Members ◽  
Prestressed Beams

Five beams were tested up to failure to study the shear behavior of concrete beams prestressed with fiber reinforced polymer (FRP). Different factors were taken into consideration: the type of prestressing tendons and the shear span ratio. The shear failure modes and the influence of different factors on shear behavior were investigated in details. The test results showed that FRP prestressed beams without stirrups had two shear failure modes: diagonal compression failure and shear compression failure; the shear span ratio was the most important factor to determine the failure mode and shear capacity of the prestressed beams. The shear capacity of concrete members prestressed with FRP tendons was lower than that of concrete beams prestressed with steel cables.

scholarly journals Development of Shear Capacity Prediction Model for FRP-RC Beam without Web Reinforcement

2016 ◽  
Vol 2016 ◽  
pp. 1-19 ◽  
Author(s):  
Md. Arman Chowdhury ◽  
Zubayer Ibna Zahid ◽  
Md. Mashfiqul Islam
Keyword(s):  
Prediction Model ◽  
Shear Capacity ◽  
Rc Beam ◽  
Rc Beams ◽  
Large Database ◽  
Steel Reinforced Concrete ◽  
Shear Design ◽  
Proposed Model ◽  
Web Reinforcement ◽  
Capacity Prediction

Available codes and models generally use partially modified shear design equation, developed earlier for steel reinforced concrete, for predicting the shear capacity of FRP-RC members. Consequently, calculated shear capacity shows under- or overestimation. Furthermore, in most models some affecting parameters of shear strength are overlooked. In this study, a new and simplified shear capacity prediction model is proposed considering all the parameters. A large database containing 157 experimental results of FRP-RC beams without shear reinforcement is assembled from the published literature. A parametric study is then performed to verify the accuracy of the proposed model. Again, a comprehensive review of 9 codes and 12 available models is done, published back from 1997 to date for comparison with the proposed model. Hence, it is observed that the proposed equation shows overall optimized performance compared to all the codes and models within the range of used experimental dataset.

Sign in / Sign up

Export Citation Format

Share Document