Flexure Behaviour the Concrete Beams Reinforcement with Polymer Materials

2013 ◽  
Vol 687 ◽  
pp. 472-479 ◽  
Author(s):  
Naser Kabashi ◽  
Cenë Krasniqi ◽  
Ali Muriqi
Keyword(s):  
Carbon Fibers ◽  
Concrete Beams ◽  
Point Load ◽  
Polymer Materials ◽  
Rc Beams ◽  
External Reinforcement ◽  
Frp Reinforcement ◽  
Beam Bending ◽  
Definition Of ◽  
Concrete Elements

Improvement of flexure behavior using the polymer materials is one of the very important factors in analyzing the concrete elements, especially concrete beams. In this case we analyze two different cases: • Improvement using the polypropylene microfibers in ready mix concrete • Improvement using the carbon fibers in external reinforcement In both case studies we used three-point-load experimental beam-bending tests for: three conventional RC beams (referent beams), three RC beams with polypropylene fibers and three RC beams with carbon fibers. All results concern comparing the effect of fibers on improvement of energy capacity of concrete elements, and increasing the bearing capacity of concrete beams. One of the most important values based on the behavior of the structure is ductility. The ductility is a structural design requirement in most design codes. The traditional definition of ductility cannot be applied in structures reinforced with FRP reinforcement. Several methods, such as the energy based method and the deformation based method have been suggested to calculate the ductility index for FRP reinforced structures. Furthermore the behavior of RC beams is analyzed with the help of cracks, their position and width under the loads.

scholarly journals Bending Performance of Concrete Beams Strengthened with Textile Reinforced Mortar TRM

2014 ◽  
Vol 601 ◽  
pp. 203-206 ◽  
Author(s):  
Lluís Gil ◽  
Christian Escrig ◽  
Ernest Bernat-Maso
Keyword(s):  
Composite Material ◽  
Carbon Fibers ◽  
Concrete Beams ◽  
Precast Concrete ◽  
High Strength ◽  
Point Load ◽  
Load Test ◽  
Bending Performance ◽  
Bending Loads ◽  
Textile Reinforced Mortar

This work presents a method of strengthening concrete structures based on textiles of high strength and mortars. The combination of textiles and mortars produces a new composite material with cementitious matrix. This material can be used for the reinforcement of concrete beams under bending loads. We tested several combinations of fibers: glass, Poliparafenil Benzobisoxazol (PBO), steel and carbon fibers with mortar and we used them to reinforce precast concrete beams. All the specimens were tested with a four-point load test. We discuss the performance of the specimens and we compare the ultimate results with the formulae from FRP codes.

scholarly journals Prestress state evolution during thermal activation of memory effect in concrete beams strengthened with external SMA wires

2020 ◽  
Vol 20 (4) ◽  
Author(s):  
A. Debska ◽  
Piotr Gwozdziewicz ◽  
A. Seruga ◽  
X. Balandraud ◽  
J. F. Destrebecq
Keyword(s):  
Ambient Temperature ◽  
Memory Effect ◽  
Concrete Beams ◽  
Macroscopic Model ◽  
Maximum Temperature ◽  
Joule Effect ◽  
Mechanical Coupling ◽  
State Evolution ◽  
Definition Of ◽  
Concrete Elements

Abstract The memory effect of shape-memory alloys (SMAs) has opened interesting perspectives to create prestress states in concrete elements. However, the procedure has not been yet fully resolved due to the complex thermomechanical behavior of these alloys, in addition to the practical difficulties of mechanical coupling between SMA and concrete elements. The present study deals with tests on the development of prestressing forces in concrete beams during the thermal cycle required in the procedure. Pre-stretched nickel–titanium wires were externally placed on concrete prismatic beams equipped with strain gauges. As concrete rupture may occur during the heating by the Joule effect, a compromise must be found between the SMA pre-stretch level and the maximum temperature to be applied before returning to ambient temperature. A macroscopic model was developed to analyze this compromise. The complex thermomechanical response of SMAs implies a particular attention in the definition of the ambient temperature and heating conditions for the creation of prestress states in concrete components.

scholarly journals Flexural Response and Failure Analysis of Solid and Hollow Core Concrete Beams with Additional Opening at Different Locations

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7203
Author(s):  
Ibrahim A. Sharaky ◽  
Ahmed S. Elamary ◽  
Yasir M. Alharthi
Keyword(s):  
Failure Modes ◽  
Concrete Beams ◽  
Load Capacity ◽  
Rc Beams ◽  
Hollow Core ◽  
Beam Length ◽  
Flexural Response ◽  
Beam Shear ◽  
Concrete Elements ◽  
Core Concrete

It is essential to make openings in structural concrete elements to accommodate mechanical and electrical needs. To study the effect of these openings on the performance of reinforced concrete (RC) elements, a numerical investigation was performed and validated using previous experimental work. The effect of the position and dimension of the opening and the beam length on the response of the beams, loads capacities, and failure modes was studied. The simulated RC beams showed different responses, loads capacities, and failure modes depending on the position and dimension of the opening. The transversal near support opening (TNSH) and longitudinal holes (LH) showed lower effects on the load capacities of the beams than the transversal near center opening (TNCH). The supreme reduction percentages of the load capacity (µu%) for beams with TNCH and TNSH were 37.21% and 30.34%, respectively (opening size = 150 × 150 mm2). In addition, the maximum µu% for beam with LH was 17.82% (opening size = 25% of the beam size). The TNSH with a width of less than 18.18% of the beam shear span (550 mm) had trivial effects on the beam’s load capacities (the maximum µu% = 1.26%). Although the beams with combined LH and TNCH or LH and TNSH showed different failure modes, they experienced nearly the same load reductions. Moreover, the length of the beam (solid or hollow) had a great effect on its failure mode and load capacity. Finally, equations were proposed and validated to calculate the yield load and post-cracking deflection for the concrete beams with a longitudinal opening.

Research on Fracture of FRP Reinforced Concrete Beams

2011 ◽  
Vol 201-203 ◽  
pp. 2931-2934
Author(s):  
Yan Feng Feng ◽  
Tian Hong Yang ◽  
Hua Wei ◽  
You Fa Gu ◽  
Hai Jun Wang
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Beams ◽  
Rc Beams ◽  
Flexural Failure ◽  
Crushed Concrete ◽  
Frp Reinforcement ◽  
Fracture Performance ◽  
Test Result

With technology of FRP reinforcement concrete beams is applied in domain of the civil engineering, it attracts more and more scholars to study it. The paper studied of the flexural fracture performance of FRP reinforced RC beams, bringing forward how to calculate the flexural failure of FRP reinforced concrete beam, namely: bearing capacity formula about broken FRP and crushed concrete on compression zone, through comparison between calculated values and tests values, it is discovered that the numerical analysis and test result is fitting approximately, it is validated that the formula can well analyze flexural of FRP reinforced RC beams.

Carrying Capacity Definition of Steel-Concrete Beams with External Reinforcement under the Fire Impact

2014 ◽  
Vol 617 ◽  
pp. 167-170 ◽  
Author(s):  
Glib Vatulia ◽  
Yevhen Orel ◽  
Maksym Kovalov
Keyword(s):  
Flame Retardant ◽  
Fire Resistance ◽  
Carrying Capacity ◽  
Concrete Beams ◽  
Three Dimensional ◽  
Design Standards ◽  
Standard Temperature ◽  
External Reinforcement ◽  
Definition Of ◽  
Fire Impact

The authors proposed the results of fire resistance evaluation of steel-concrete beams with external sheet reinforcement at standard temperature range of fire in the room and justified specifications for flame-retardant coat due to design standards. In order to analyze fire resistance the three-dimensional computer models were developed taking into account the basic conditions of beams loading and bearing as well as non-linear "stress-strain" dependencies of concrete and external reinforcement.

Calculation Of Carbon Fiber Anchors For Pull-Out And Shear When Installing External Reinforcement Systems

2020 ◽  
pp. 4-8
Keyword(s):  
Composite Materials ◽  
Carbon Fibers ◽  
Experimental Studies ◽  
The Body ◽  
Carbon Fibres ◽  
Calculation Methods ◽  
Regulatory Documents ◽  
Pull Out ◽  
External Reinforcement ◽  
Concrete Elements

The operation of external reinforcement systems based on carbon fibers when strengthening normal and inclined sections of bending reinforced concrete elements depends largely on the anchoring to the body of the reinforced structure. In addition to adhesion, one of the options for ensuring the required level of anchoring of external reinforcement is the installation of anchoring elements, including those based on carbon fibers. This article discusses the calculation of anchors based on carbon fibres used in the arrangement of the external reinforcement system. Two principles of anchor arrangement operation are highlighted: for shear and for pull-out. Separate design provisions have been developed for each, taking into account the parameters of anchoring elements and the nature of the destruction obtained during experimental studies. The proposed calculation methods are based on experimental studies of both bending elements reinforced by external reinforcement systems and directly anchoring elements. In addition, the development of these methods takes into account the provisions available in the regulatory documents on the calculation of anchors and composite materials.

scholarly journals Ductility of Concrete Beams Reinforced with FRP Rebars

Buildings ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 424
Author(s):  
Tvrtko Renić ◽  
Tomislav Kišiček
Keyword(s):  
Experimental Data ◽  
Theoretical Analysis ◽  
Cross Sections ◽  
Concrete Beams ◽  
Current Knowledge ◽  
Bending Moment ◽  
Bending Capacity ◽  
Frp Reinforcement ◽  
Concrete Elements ◽  
Standard Steel

Concrete beams reinforced with FRP rebars have greater durability than standard steel reinforced elements. The main disadvantage of using FRP rebars is the low ductility of elements which may be unacceptable in certain situations. There are several different ways of increasing the ductility of concrete elements, which are analyzed in this paper. They are compared based on efficiency, influence on durability and ease of construction. Less analyzed and tested methods are given more attention to try and expand the current knowledge and possibilities. For methods that lack experimental data, theoretical analysis is undertaken to assess the possible influence of that method on the increase in ductility. Ductility was obtained by calculating bending moment–curvature diagrams of cross sections for different reinforcement layouts. One method that lacks experimental data is confining the compressive area of beams with tensile FRP reinforcement. Theoretical analysis showed that confining the compressive area of concrete can significantly increase the ductility and bending capacity of beams. Since experimental data of beams reinforced with FRP rebars in tension and confined compressive area is sparse, some suggestions on the possible test setups are given to validate this theoretical analysis. Concrete beams reinforced with FRP can be detailed in such a way that they have sufficient ductility, but additional experimental research is needed.

scholarly journals Experimental study of RC beams strengthened for bending by reinforced grout layer and connectors

2018 ◽  
Vol 11 (4) ◽  
pp. 810-833
Author(s):  
J. H. CANAVAL ◽  
T. J. DA SILVA ◽  
A. C. SANTOS
Keyword(s):  
Experimental Study ◽  
Experimental Investigation ◽  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Concrete Beams ◽  
Point Load ◽  
Reinforced Concrete Beams ◽  
Bending Test ◽  
Experimental Program ◽  
Rc Beams

Abstract This work is based on an experimental investigation of reinforced concrete beams strengthened to flexure for wrapping applying a type of metallic connector in the bond substrate/groute. The experimental program consisted of 5 beams used for reference (without strengthening), 5 beams reinforced with surface brushed texture substrate and 5 beams with metal connectors bonded to the substrate. The beams were submitted to four-point load bending test. Initially with a partial loading, executed the strengthening and were finally tested until the break. The strengthening was made up by the increase by graute, on the sides and bottom of the beam and reinforcing. The applied force, the displacement, deformations in steel and in concrete were measured. The reference beams failure by flexing with the calculated charges. The bending strengthening proved efficient, increasing the bearing capacity in 44% and the failure was by shear in the stretch without strengthening. Beams with connectors the increase was higher.

Nonlinear Analysis of FRP SRC Concrete Beams

2011 ◽  
Vol 393-395 ◽  
pp. 201-204
Author(s):  
Le Zhou ◽  
Xiao Xing Liu ◽  
Ying Li ◽  
Dong Yan
Keyword(s):  
Nonlinear Analysis ◽  
Concrete Beams ◽  
Simulation Analysis ◽  
Sheet Steel ◽  
Section Size ◽  
Fiber Reinforce Plastic ◽  
Frp Reinforcement ◽  
Beam Bending ◽  
Beam Section ◽  
Fiber Reinforce

On the basis of the theory of FRP sheet steel reinforcing concrete beams (SRC-beams), in order to better explore the force performance of FRP (Fiber Reinforce Plastic) steel reinforcing concrete beams, this paper analyzes the stress process simulation of the beam using the computer program of nonlinear analysis. In order to validate the program of the beam section the reliability of the simulation analysis, this paper brings beam section size and its material performance parameters into program and gets different parameters on the bearing capacity of beams influence law. Research shows that when working in the stage of FRP elasticity the reinforcement of FRP layers has little influence on bend curvature figure. In the elastic-plastic stage it has larger influence and the cure increases with the increase of FRP reinforcement layer. It shows that with the increase of the section stiffness beam bending flexural capacity is also bigger.

Torsional Behavior of RC Beams Strengthened With Carbon Fiber Reinforced Polymer Composites

2021 ◽  
pp. 136943322098862
Author(s):  
Leandro Ferreira Silva ◽  
Emil de Souza Sánchez Filho ◽  
Julio Jeronimo Holtz Silva Filho
Keyword(s):  
Theoretical Model ◽  
Carbon Fibers ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Rc Beams ◽  
Torsion Angles ◽  
Reinforced Polymer ◽  
Fiber Reinforced Polymer Composites

This paper shows a theoretical model for reinforced concrete beams subjected to torsion and strengthened with composite of carbon fibers (CFRP). It is based on researches of Michael Collins and collaborators and approaches the theory of diagonal compressive field. This model was inserted in a mathematic software, due to the need of interactions to obtain the torsion and torsion angles. The validation of theoretical values was realized through the results of tests obtained from the literature and it was understood that the model is valid and conservative for the ultimate torsion in most of the studies carried out. However, the beams that had the geometric ratios width and height b/h < 0.5 and the ratio between the cover and the smaller dimension of the d/cob element ≤6 had not so accurate results.

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