scholarly journals ANALYSIS OF SHEAR DESIGN RECOMMENDATIONS FOR FRP REINFORCED CONCRETE BEAMS

2018 ◽  
Vol 10 (2) ◽  
pp. 46-57
Author(s):  
Marius Budvytis ◽  
Alfonso Cobo Escamilla ◽  
Linas Juknevičius
Keyword(s):  
Reinforced Concrete ◽  
Comparative Analysis ◽  
Coefficient Of Variation ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Design Model ◽  
Design Models ◽  
Shear Design ◽  
Proposed Model ◽  
Frp Reinforcement

Research shows that most shear design models for concrete beams reinforced with FRP reinforcement provide conservative results that leads to excessive amounts of reinforcement and increased overall cost of such construction. This paper presents comparative analysis of current shear design models for concrete beams reinforced with longitudinal FRP reinforcement and FRP stirrups. New analytical shear design model, developed by Valivonis et al., has been included in the analysis. A database with 88 specimens reinforced with FRP reinforcement was compiled in order to verify the accuracy of the proposed model by Valivonis et al. It is shown that proposed shear design model yields quite accurate and consistent results as an average of Vexp / Vpred values is 0.98 and coefficient of variation is 26.0% for this model.

scholarly journals Ultimate Shear of RC Beams with Corroded Stirrups and Strengthened with FRP

Buildings ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 34 ◽  
Author(s):  
Nino Spinella ◽  
Piero Colajanni ◽  
Antonino Recupero ◽  
Francesco Tondolo
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Effective Strain ◽  
Stress Rupture ◽  
Reinforced Concrete Beams ◽  
Good Ability ◽  
Proposed Model ◽  
Frp Reinforcement ◽  
Corrosion Of Steel

Transverse reinforcement plays a key role in the response behavior of reinforced concrete beams. Therefore, corrosion of steel stirrups may change the failure mode of elements from bending to shear, leading to a brittle and catastrophic crisis. It is important to strengthen reinforced concrete beams with corroded stirrups to enhance the shear resistance. This paper presents a formulation, based on the modified compression field theory, to estimate the ultimate shear of reinforced concrete beams strengthened with FRP, because of stirrup corrosion. The detrimental effect of corrosion on steel stirrup yield strength was taken into account by introducing an empirical decay law. The effective strain of FRP reinforcement was adequately evaluated by considering both debonding and tensile stress rupture. The proposed model was validated against collected experimental results, showing a good ability to evaluate shear strength. Moreover, a numerical analysis was carried out to highlight the role of the key parameters predicting the ultimate shear.

Does the shear strength of reinforced concrete beams and slabs depend upon the flexural reinforcement ratio or the reinforcement strain?

2013 ◽  
Vol 40 (11) ◽  
pp. 1068-1081 ◽  
Author(s):  
Mitra Noghreh Khaja ◽  
Edward G. Sherwood
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Concrete Beams ◽  
Reinforcement Ratio ◽  
Reinforced Concrete Beams ◽  
Shear Stresses ◽  
Shear Design ◽  
Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
General Method

Beam tests are conducted to investigate the effect of the reinforcement ratio, ρ, and the shear span to depth ratio, a/d, on the shear strength of reinforced concrete beams and slabs without stirrups. The a/d ratio is shown to have a very significant effect on shear strength at both low values of a/d (where failure is governed by strut-and-tie mechanisms) and large values of a/d (where failure is governed by breakdown in beam action). Increases in ρ associated with increases in a/d such that the strain, or M/ρVd ratio, is kept constant will result in constant failure shear stresses. Shear design methods that do not account for a/d (e.g., ACI Committee 440) cannot predict the observed experimental behaviour, whereas the general method of the CSA A23.3 code can. Using the ACI 440 equation for Vc may reduce the economic competitiveness of fibre-reinforced polymer reinforcement versus steel reinforcement.

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