Experimental Investigation Dowel Action of Longitudinal Reinforcement of Reinforced Concrete Beams

This paper presents an experimental investigation on the behavior of bubbled wide reinforced concrete beams with different shear steel plate spacing. Four specimens with the dimensions of 215x560x1800mm are investigated. The variables studied in this work is using the 10mm stirrups with 125mm spacing and 3mm thickness steel plate with spacing 125, 166 and 250mm instead of reinforcing stirrups. Shear steel plates is good alternative for replacing the stirrups and gives increasing in yield and ultimate loads with 17% and 18% respectively and decreasing the deflection by 8% at yield and 12% at ultimate. Moreover decrease the strain in longitudinal reinforcement by 8% at yield and 24% at ultimate, and reduced the total weight by 2.7%. By increasing the spacing of shear steel plate by 33% and 100%, the results showed that the yield load reduced to 3% and 4% respectively, but the deflection was increased with 37% and 20% (at yield). The strain in interior legs is more than the strain in exterior legs by 189%, 142% and 52% at yield for spacing 125, 166 and 250mm respectively. ACI 318-14 [1] and EC 2 [2] codes give a predicted deflection more than the experimental deflection by 26% and 30% on average respectively

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Reinforced concrete beams strengthened with SRP/SRG systems: Experimental investigation

Construction and Building Materials ◽

10.1016/j.conbuildmat.2015.06.027 ◽

2015 ◽

Vol 93 ◽

pp. 654-677 ◽

Cited By ~ 41

Author(s):

Annalisa Napoli ◽

Roberto Realfonzo

Keyword(s):

Experimental Investigation ◽

Reinforced Concrete ◽

Concrete Beams ◽

Reinforced Concrete Beams

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Experimental analysis of steel fiber reinforced concrete beams in shear

Revista IBRACON de Estruturas e Materiais ◽

10.1590/s1983-41952022000300001 ◽

2022 ◽

Vol 15 (3) ◽

Author(s):

Aaron Kadima Lukanu Lwa Nzambi ◽

Dênio Ramam Carvalho de Oliveira ◽

Marcus Vinicius dos Santos Monteiro ◽

Luiz Felipe Albuquerque da Silva

Keyword(s):

Shear Strength ◽

Reinforced Concrete ◽

Steel Fiber ◽

Concrete Beams ◽

Reinforcement Ratio ◽

Steel Fibers ◽

Reinforced Concrete Beams ◽

Experimental Program ◽

Longitudinal Reinforcement ◽

Fiber Addition

Abstract Some normative recommendations are conservative in relation to the shear strength of reinforced concrete beams, not directly considering the longitudinal reinforcement rate. An experimental program containing 8 beams of (100 x 250) mm2 and a length of 1,200 mm was carried out. The concrete compression strength was 20 MPa with and without 1.00% of steel fiber addition, without stirrups and varying the longitudinal reinforcement ratio. Comparisons between experimental failure loads and main design codes estimates were assessed. The results showed that the increase of the longitudinal reinforcement ratio from 0.87% to 2.14% in beams without steel fiber led to an improvement of 59% in shear strength caused by the dowel effect, while the corresponding improvement was of only 22% in fibered concrete beams. A maximum gain of 109% in shear strength was observed with the addition of 1% of steel fibers comparing beams with the same longitudinal reinforcement ratio (1.2%). A significant amount of shear strength was provided by the inclusion of the steel fibers and allowed controlling the propagation of cracks by the effect of stress transfer bridges, transforming the brittle shear mechanism into a ductile flexural one. From this, it is clear the shear benefit of the steel fiber addition when associated to the longitudinal reinforcement and optimal values for this relationship would improve results.

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