scholarly journals Numerical analysis of reinforced concrete beams pre cracked reinforced by composite materials

2020 ◽  
Vol 14 (54) ◽  
pp. 282-296
Author(s):  
Fatima Benaoum ◽  
Foudil Khelil ◽  
Ali Benhamena
Keyword(s):  
Reinforced Concrete ◽  
Composite Materials ◽  
Epoxy Resin ◽  
Breaking Load ◽  
Reinforced Concrete Beams ◽  
Lateral Part ◽  
Good Precision ◽  
Initial State ◽  
Building Site ◽  
The One

This work constitutes a contribution to the analysis of the behavior of beams reinforced by composite materials. The analysis was made by a study on concrete elements, and in pre-cracked reinforced concrete then reinforced with carbon fiber fabric bonded in tusi using an epoxy resin. In order to study the influence of the initial state of cracking, one of the beams was reinforced without it being pre-cracked and was compared to a pre-cracked and reinforced beam then to another loaded until rupture without being pre-cracked or reinforced and neither reinforced. the beams were pre-cracked and reinforced in their stretched part and on the lateral part with bands of different dimensions in order to avoid delamination on the one hand and to study the recovery of the composite under the effect of shearing and detachment on the other hand. However, the arrival of these structures brings new scientific problems and in particular the mode of rupture. The aim of this work is to increase the bearing capacity, reduce the deflection and limit the opening of cracks by ensuring better behavior of this element. The results obtained showed that the bonding of composite materials on reinforced concrete structures gave an increase in the ultimate breaking load and a reduction in deformations in concrete and steels. The results of this method coincide perfectly with those from the literature. The reinforcement allowed a significant increase in the breaking load and a reduction in the deflection at break up to 80%. The theoretical model based on the theory of modified reinforced concrete made it possible to predict with good precision the behavior in bending until the ultimate and it would be possible to use the fabric and the epoxy resin for the reinforcement in bending in building site, beams.

scholarly journals EXPERIMENTAL STUDIES OF REINFORCED CONCRETE BEAMS STRENGTHENED WITH STEEL FIBER JACKET

2020 ◽  
pp. 34-45
Author(s):  
O. Radaikin ◽  
L. Sharafutdinov
Keyword(s):  
Reinforced Concrete ◽  
Steel Fiber ◽  
Concrete Beams ◽  
Experimental Studies ◽  
Breaking Load ◽  
Fiber Reinforced Concrete ◽  
Reinforced Concrete Beams ◽  
Steel Fiber Reinforced Concrete ◽  
Joint Work ◽  
Loaded Crack

The purpose of the study is to experimentally study the joint work of steel fiber reinforced concrete (SFB) reinforcement jacket and reinforced concrete beams at all stages of loading to further develop a methodology for calculating this method of reinforcing bending elements. The main results of the study consist in assessing the strength, stiffness, fracture toughness, as well as the nature of fracture with a picture of the development of cracks for the examined 4 samples (two with a jacket of reinforcement, two - control - without reinforcement). It has been established that the use of SFB jacket with a thickness of 45 mm and with a fiber content percentage of 2,5% (at a flow rate of 196 kg/m3) increases the breaking load by 20 %, stiffness from 3,4 to 11 times as it is loaded, crack resistance 2,4-2,8 times. The results are compared with computer modeling in ANSYS PC: the discrepancy in the load of crack formation, fracture and deflection values for full-scale samples and a computer model are within 6,3 %, which indicates the reliability of the numerical results and the possibility of using the proposed computer models in further studies on topic of the article.

Moment Capacity of FRP Reinforced Concrete Beam Assessment Based on Centerline Geometry

2013 ◽  
Vol 486 ◽  
pp. 211-216
Author(s):  
Jan Zatloukal ◽  
Petr Konvalinka
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Reinforced Concrete Beam ◽  
Steel Reinforcement ◽  
Reinforced Concrete Beams ◽  
Flexural Behavior ◽  
Moment Capacity ◽  
Frp Composite ◽  
Load Carrying ◽  
The One

The flexural behavior of FRP (Fiber Reinforced Polymer) reinforced concrete beam has been the topic of intensive previous research, because of the spread of use of modern FRP composite materials in the building industry as concrete reinforcement. The behavior of FRP reinforced member is different from the one reinforced with regular steel reinforcement, mainly because of vast difference between moduli of elasticity of FRP composite reinforcement bars and steel. This difference results in the fact that conventional design methods used for years in the field of reinforced concrete structures using steel reinforcement give poor results if attempted use with FRP reinforced structural members. Results of conventional methods are so poor that use of such methods would be dangerous they tend to overestimate load carrying capacity and underestimate deformations both resulting in unsafe predictions. This paper points to formulating easy to use and comprehensible method of predicting moment capacity of FRP reinforced concrete beams subjected to bending loading and validation of the proposed method via set of experiments.

scholarly journals Behavior of reinforced concrete beams pre-cracked and repaired by composite materials under static loading

2018 ◽  
Vol 149 ◽  
pp. 02017
Author(s):  
Mostefa Hamrat ◽  
Bensaid Boulekbache ◽  
Halima Bouziane ◽  
Hayet Benkara
Keyword(s):  
Reinforced Concrete ◽  
Composite Materials ◽  
Failure Modes ◽  
Concrete Beams ◽  
Theoretical Models ◽  
Mean Value ◽  
Concrete Cover ◽  
Reinforced Concrete Beams ◽  
Fiber Glass ◽  
Lift Off

This work constitutes a contribution to the analysis of the behavior of beams repaired by composite materials. To analyze the overall behavior and failure modes of the beams, an experimental study of nine reinforced concrete beams, pre-cracked and then repaired by composite materials was conducted. Six beams were pre-cracked and repaired in the tensioned part (bending repair) and in the other two beams on the tensioned and lateral parts with strips in the shape of U (shear repair). A comparative study was made between the ultimate moments measured experimentally and those calculated by the theoretical models. Compared to the control beam, the resistance gain for the beams repaired in bending is 50% to 90%, while that of beams repaired in shear is from 120% to177 %. The beams repaired in shear exhibit a ductile rupture in bending. However, the beams repaired in bending were failed by the lift-off of composite or by failure of concrete cover layer (except for beams repaired by fiber glass). BAEL99, EC2-04 and ACI318-08 models give the best prediction of the ultimate moments with a mean value of 1.16 for the ratio of MExp./Mtheor. and a mean standard deviation of 0.33.

Experimental Study on Reinforcement of Failure Reinforced Concrete Beams

2013 ◽  
Vol 275-277 ◽  
pp. 1264-1267
Author(s):  
Qian Chen ◽  
Ling Yong Liu ◽  
Yang Jun Meng
Keyword(s):  
Experimental Study ◽  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Epoxy Resin ◽  
Cross Section ◽  
Concrete Beams ◽  
Experimental Results ◽  
Reinforced Concrete Beams ◽  
Carbon Cloth ◽  
Structural Failure

Through repair and reinforcement of breaking reinforced concrete beams by epoxy resin and carbon cloth, and its experiment, the crack and deformation and bearing capacity as well as ductility of such beams are obtained. Experimental results show that the ultimate bearing capacity of beams after reinforcement increased by 210%, the structure ductility fell by 170%, structural failure form is similar to failure in normal cross section.

scholarly journals Reinforced concrete beams coated with fiberglass-reinforced polymeric profiles as partial substitutes for the transverse reinforcement

2020 ◽  
Vol 13 (6) ◽  
Author(s):  
Igor Souza Hoffman ◽  
Jorge Henrique Piva ◽  
Augusto Wanderlind ◽  
Elaine Guglielmi Pavei Antunes
Keyword(s):  
Reinforced Concrete ◽  
Composite Structures ◽  
Mechanical Performance ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Fiber Reinforced Polymers ◽  
Transverse Reinforcement ◽  
Structural Applications ◽  
The Moment ◽  
The One

abstract: The use of GFRP (Glass Fiber Reinforced Polymers) structural profiles in the construction sector is growing due to their attractive properties, such as high mechanical strength and durability in aggressive environments. With this, it is necessary to conduct studies that deepen the knowledge about the performance of these materials in structural applications. Therefore, this work aims to analyze the mechanical performance of reinforced concrete beams coated with GFRP profiles, in comparison to reinforced concrete beams, by analyzing groups with different spacing between transversal reinforcement. In all groups there was no change in the longitudinal reinforcement, and the D and Q groups were, respectively, made up of transverse reinforcement spaced twice and quadruple the one calculated for the reference beams, and presented the GFRP profiles in their constitution. All beams were tested at four-point bending, and strain gauges were installed in one of the beams of each group studied. The results obtained in the tests showed an increase in strength of 83.67% in the beams of group D, and 79.91% for group Q, in relation to the references. The analysis of longitudinal deformations made it possible to verify increases in stiffness and the moment of cracking in composite beams. Thus, based on this study, the composite structures studied may constitute future solutions for constructions exposed to aggressive environmental conditions, in order to increase their durability and also to contribute to the design of such structural elements with lower reinforcement rates.

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