Design procedure and simplified equations for the flexural capacity of concrete members reinforced with fibre-reinforced polymer bars

2012 ◽  
Vol 13 (2) ◽  
pp. 119-129 ◽  
Author(s):  
Lluis Torres ◽  
Kyriacos Neocleous ◽  
Kypros Pilakoutas
Keyword(s):  
Design Procedure ◽  
Flexural Capacity ◽  
Concrete Members ◽  
Reinforced Polymer ◽  
Fibre Reinforced Polymer

Flexural Characteristics of Concrete Beams Reinforced with a New Type of GFRP Bar

2009 ◽  
Vol 17 (4) ◽  
pp. 253-264 ◽  
Author(s):  
Hongseob Oh ◽  
Do Young Moon ◽  
Goangseup Zi
Keyword(s):  
Theoretical Model ◽  
American Concrete Institute ◽  
Concrete Cover ◽  
Flexural Capacity ◽  
Concrete Members ◽  
Reinforced Polymer ◽  
Glass Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Glass Fibre Reinforced ◽  
New Type

Beam tests were conducted to investigate the characteristics of a newly developed type of glass fibre-reinforced polymer (GFRP) rebar as reinforcement in flexural concrete members. Nine beams over-reinforced with different types of rebar, and with varying reinforcement ratios and depths of concrete cover, were monotonically loaded up to failure. Results were characterised by failure mode, moment–curvature, flexural capacity, load–deflection, and crack width. The test results were compared with the theoretical model and the American Concrete Institute design guide, which showed that the performance of the newly- developed GFRP rebar was comparable to commercially available GFRP rebars. In addition, a theoretical model for moment–curvature and an equation for predicting the flexural capacity of the beams with multiple layers of GFRP rebar are presented, based on the experimental observations.

Minimum thickness of concrete members reinforced with fibre reinforced polymer bars

2001 ◽  
Vol 28 (4) ◽  
pp. 583-592 ◽  
Author(s):  
Amin Ghali ◽  
Tara Hall ◽  
William Bobey
Keyword(s):  
Reinforced Concrete ◽  
Minimum Thickness ◽  
Reinforced Polymers ◽  
Flexural Members ◽  
Steel Reinforced Concrete ◽  
Concrete Members ◽  
Reinforced Polymer ◽  
Steel Bars ◽  
Fibre Reinforced Polymer ◽  
Frp Bars

To avoid excessive deflection most design codes specify the ratio (l/h)s, the span to minimum thickness of concrete members without prestressing. Use of the values of (l/h)s specified by the codes, in selecting the thickness of members, usually yields satisfactory results when the members are reinforced with steel bars. Fibre reinforced polymer (FRP) bars have an elastic modulus lower than that of steel. As a result, the values of (l/h)s specified in codes for steel-reinforced concrete would lead to excessive deflection if adopted for FRP-reinforced concrete. In this paper, an equation is developed giving the ratio (l/h)f for use with FRP bars in terms of (l/h)s and (εs/εf), where εs and εf are the maximum strain allowed at service in steel and FRP bars, respectively. To control the width of cracks, ACI 318-99 specifies εs = 1200 × 10–6 for steel bars having a modulus of elasticity, Es, of 200 GPa and a yield strength, fy, of 400 MPa. At present, there is no value specified for εf; a value is recommended in this paper.Key words: concrete, cracking, deflection, fibre reinforced polymers, flexural members, minimum thickness.

scholarly journals FLEXURAL CAPACITY OF CONCRETE BEAMS REINFORCED WITH STEEL AND FIBRE‐REINFORCED POLYMER (FRP) BARS

2004 ◽  
Vol 10 (3) ◽  
pp. 209-215
Author(s):  
Hau Yan Leung
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Concrete Members ◽  
Reinforced Polymer ◽  
Beam Design ◽  
Reinforced Concrete Member ◽  
Current Design ◽  
Fibre Reinforced Polymer ◽  
Steel Rebars ◽  
Frp Bars

Although much research on concrete beams reinforced with fibre‐reinforced polymer (FRP) rods has been conducted in recent years, their use still does not receive the attention it deserves from practicising engineers. This is attributed to the fact that FRP is brittle in nature and the collapse of FRP‐reinforced concrete member may be catastrophic. A rational beam design can incorporate a hybrid use of FRP rods and steel rods. Current design codes only deal with steel‐reinforced or FRP‐reinforced concrete members. Therefore in this study some design charts and equations for concrete beam sections reinforced with FRP rods and steel rebars were generated. Results from the theoretical derivations agreed well with experimental data.

Long-term deflection prediction of concrete members reinforced with glass fibre reinforced polymer bars

2000 ◽  
Vol 27 (5) ◽  
pp. 890-898 ◽  
Author(s):  
Tara Hall ◽  
Amin Ghali
Keyword(s):  
Glass Fibre ◽  
Steel Reinforced Concrete ◽  
Model Code ◽  
Concrete Members ◽  
Reinforced Polymer ◽  
Reinforced Beams ◽  
Glass Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Glass Fibre Reinforced

This paper presents the results of an experimental investigation of the long-term deflection behaviour of concrete shallow beams reinforced with glass fibre reinforced polymer (GFRP) bars. The long-term deflections of the GFRP-reinforced beams are compared to deflections of identical beams reinforced with steel bars. All beams were under sustained loading for approximately 8 months. The variables were the level of sustained loading and the reinforcement materials: steel or GFRP. The experimental immediate and long-term deflections of both the steel- and the GFRP-reinforced beams were compared to calculated deflections using the CEB-FIP Model Code 1990, and the ACI 318-95 code using the recommendations of ACI Committee 209; these references are for steel reinforced concrete members. The test results indicate that under similar loading conditions and the same reinforcement ratio, the GFRP-reinforced beams had long-term deflections, due to creep and shrinkage, 1.7 times greater than those of the steel-reinforced beams. A comparison of the theoretical and experimental immediate and long-term deflections indicates that the CEB-FIP Model Code 1990 gives reasonable predictions for all beams, and that the ACI 318-95 code, using the ACI Committee 209 recommendations, overestimates the deflections due to the combined effects of creep and shrinkage.Key words: glass fibre reinforced polymer (GFRP), steel, reinforced concrete, long-term, deflections, flexure, elastic modulus.

scholarly journals OPTIMISATION OF THICKNESS OF FIBRE REINFORCED POLYMER SHEETS FOR STRENGTHENING REINFORCED CONCRETE BEAMS WITH FLEXURAL DEFICIENCY

2016 ◽  
Vol 36 (1) ◽  
pp. 45-49
Author(s):  
JM Kaura
Keyword(s):  
Reinforced Concrete ◽  
High Capacity ◽  
Cost Effective ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Beams ◽  
Concrete Members ◽  
Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Reduced Gradient ◽  
Generalized Reduced Gradient

The use of Fiber Reinforced Polymer (FRP) is becoming a widely accepted solution for repairing and strengthening of deteriorated reinforced concrete members, to restore their load carrying capacities. One of the major concerns in the use of FRP is its cost. This therefore calls for the use of efficient and cost effective design approach. Design efficiency in terms of cost can be achieved through optimisation. In the present paper, Generalized Reduced Gradient (GRG) optimisation technique was employed to optimize the strengthening cost of a simply supported reinforced concrete beam strengthened with Fibre Reinforced Polymer (FRP). Optimum design charts for the considered problem were presented. The results showed that considerable savings in thickness can be achieved using FRP of high modulus of elasticity. For example at very high capacity reduction say 70% (kc = 0.3), the required FRP thicknesses for FRP with elastic moduli of 25GPa, 50GPa, 75GPa, 100GPa, 125GPa and 150GPa are respectively equal to 2.5mm, 1.75mm, 0.75mm, 0.6mm, 0.5mm and 0.4mm.  http://dx.doi.org/10.4314/njt.v36i1.7

The impact of fire on seismic resistance of fibre reinforced polymer strengthened concrete structural systems

2013 ◽  
Vol 40 (11) ◽  
pp. 1044-1049 ◽  
Author(s):  
Noureddine Bénichou ◽  
Hossein Mostafaei ◽  
Mark F. Green ◽  
Kevin Hollingshead
Keyword(s):  
Numerical Models ◽  
Load Resistance ◽  
Seismic Resistance ◽  
Fire Exposure ◽  
Concrete Members ◽  
Standard Fire ◽  
Reinforced Polymer ◽  
Structural Resistance ◽  
Fibre Reinforced Polymer ◽  
The Impact

This paper presents the results of a research project to study the seismic resistance of fibre reinforced polymer (FRP) strengthened concrete members after fire exposure. Specifically, the paper presents results of FRP strengthened reinforced concrete columns exposed to a standard fire including temperatures measured during the test and a discussion of the loads applied to the columns. Finally, the paper also presents the impact of lateral loading on structural columns after fire to assess the effectiveness of structural resistance of fire-damaged FRP strengthened building elements in case of an earthquake. Numerical models to simulate the lateral behaviour are presented and the predictions are compared to the test results. Since the FRP strengthened columns were insulated with fire protection, the lateral load resistance of the unstrengthened column was reduced by less than 5% due to fire exposure.

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