Influence of Spatial Variability on the Shear Capacity of RC Members without Shear Reinforcement

2013 ◽  
Vol 99 (7) ◽  
pp. 1679-1686
Author(s):  
Yuguang Yang ◽  
Joop Den Uijl ◽  
Joost Walraven ◽  
Stavros Petrocheilos
Bauingenieur ◽  
2020 ◽  
Vol 95 (11) ◽  
pp. 397-407
Author(s):  
Viviane Adam ◽  
Martin Herbrand ◽  
Josef Hegger

Zusammenfassung Neben gestiegenen Verkehrslasten führen strengere normative Regeln zu höheren Anforderungen an Spannbetonbrücken. Viele ältere Spannbetonbrücken im Bestand weisen daher rechnerische Defizite bei der Querkrafttragfähigkeit auf. Durch experimentelle und theoretische Untersuchungen konnten im Zuge eines Forschungsprojekts für die Bundesanstalt für Straßenwesen (BASt) verfeinerte Berechnungsansätze für Querkraft erarbeitet werden. In diesem Beitrag werden am Institut für Massivbau der RWTH Aachen (IMB) durchgeführte Großversuche an Spannbetondurchlaufträgern vorgestellt. Die Träger mit Rechteck- oder I-Profil wiesen geringe Querkraftbewehrungsgrade auf und wurden durch Gleichstreckenlasten beansprucht. Auf Basis der Forschungsergebnisse wurde ein verfeinertes Bemessungsmodell entwickelt, das aus einem modifizierten Fachwerkmodell mit additivem Betontraganteil besteht und gegenüber dem Ansatz nach aktueller Nachrechnungsrichtlinie weitere Querkrafttragreserven berücksichtigt.


Buildings ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 423
Author(s):  
Nancy Kachouh ◽  
Tamer El-Maaddawy ◽  
Hilal El-Hassan ◽  
Bilal El-Ariss

Results of an experimental investigation aimed at studying the effect of steel fibers on the shear behavior of concrete deep beams made with a 100% recycled concrete aggregate (RCA) are presented in this paper. The study comprised testing of seven concrete deep beam specimens with a shear span-to-depth ratio (a/h) of 1.6. Two beams were made of natural aggregates (NAs) without steel fibers, two beams were made of a 100% RCA without steel fibers, and three beams were made of RCA-based concrete with steel fibers at volume fractions (vf) of 1, 2, and 3%. Two of the beams without steel fibers included a minimum shear reinforcement. Test results showed that the beam with a 100% RCA without steel fibers exhibited a lower post-cracking stiffness, reduced shear cracking load, and lower shear capacity than those of the NA-based control beam. The detrimental effect of the RCA on the shear response was less pronounced in the presence of the minimum shear reinforcement. The addition of steel fibers significantly improved the shear response of the RCA-based beams. The post-cracking stiffness of the RCA-based concrete beams with steel fibers coincided with that of a similar beam without fibers containing the minimum shear reinforcement. The use of steel fibers in RCA beams at vf of 1 and 2% restored 80 and 90% of the shear capacity, respectively, of a similar beam with the minimum shear reinforcement. The response of the RCA specimen with vf of 3% outperformed that of the NA-based control beam with the minimum shear reinforcement, indicating that steel fibers can be used in RCA deep beams as a substitution to the minimum shear reinforcement. The shear capacities obtained from the tests were compared with predictions of published analytical models.


2014 ◽  
Vol 14 (3) ◽  
pp. 211-231 ◽  
Author(s):  
Deuck Hang Lee ◽  
Min-Kook Park ◽  
Jae-Yuel Oh ◽  
Kang Su Kim ◽  
Ju-Hyeuk Im ◽  
...  

2006 ◽  
Vol 33 (8) ◽  
pp. 933-944 ◽  
Author(s):  
H El Chabib ◽  
M Nehdi ◽  
A Saïd

The exact effect that each of the basic shear design parameters exerts on the shear capacity of reinforced concrete (RC) beams without shear reinforcement (Vc) is still unclear. Previous research on this subject often yielded contradictory results, especially for reinforced high-strength concrete (HSC) beams. Furthermore, by simply adding Vc and the contribution of stirrups Vs to calculate the ultimate shear capacity Vu, current shear design practice assumes that the addition of stirrups does not alter the effect of shear design parameters on Vc. This paper investigates the validity of such a practice. Data on 656 reinforced concrete beams were used to train an artificial neural network model to predict the shear capacity of reinforced concrete beams and evaluate the performance of several existing shear strength calculation procedures. A parametric study revealed that the effect of shear reinforcement on the shear strength of RC beams decreases at a higher reinforcement ratio. It was also observed that the concrete contribution to shear resistance, Vc, in RC beams with shear reinforcement is noticeably larger than that in beams without shear reinforcement, and therefore most current shear design procedures provide conservative predictions for the shear strength of RC beams with shear reinforcement.Key words: analysis, artificial intelligence, beam depth, compressive strength, modeling, shear span, shear strength.


2014 ◽  
Vol 13 (3) ◽  
pp. 151-158
Author(s):  
Marta Słowik

In the paper, the influence of longitudinal reinforcement on shear capacity of reinforced concrete members without shear reinforcement is discussed. The problem is analyzed on the basis of the author’s own test results and tests results reported in the professional literature. It has been concluded that longitudinal reinforcement has an effect on shear capacity especially in members of shear span-to-depth ratio a/d < 2,5. The test results have also been used to verify standard methods of calculating the shear capacity in reinforced concrete members without shear reinforcement given in Eurocode 2, ACI Standard 318 and Model Code 2010.


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