Design guidelines for fibre-reinforced polymer (FRP)-strengthened reinforced concrete (RC) structures

2008 ◽  
Author(s):  
J Chen ◽  
S Smith
Keyword(s):  
Reinforced Concrete ◽  
Design Guidelines ◽  
Rc Structures ◽  
Reinforced Polymer ◽  
Fibre Reinforced Polymer

Effect of freeze–thaw cycling on the behaviour of reinforced concrete beams strengthened in flexure with fibre reinforced polymer sheets

2003 ◽  
Vol 30 (6) ◽  
pp. 1081-1088 ◽  
Author(s):  
Mark F Green ◽  
Aaron J.S Dent ◽  
Luke A Bisby
Keyword(s):  
Reinforced Concrete ◽  
Test Data ◽  
Concrete Beams ◽  
Design Guidelines ◽  
Reinforced Concrete Beams ◽  
Bending Test ◽  
Small Scale ◽  
Freeze Thaw ◽  
Reinforced Polymer ◽  
Fibre Reinforced Polymer

Externally bonded fibre reinforced polymer (FRP) plates and sheets for strengthening and rehabilitating existing reinforced concrete structures have recently received a great deal of attention within the civil engineering community. Many tests have shown the benefits of FRP, but more information is required on their behaviour in cold regions. Twenty-seven small-scale concrete beams (100 mm × 150 mm × 1220 mm) were strengthened with FRP in flexure (and in some cases also in shear), subjected to up to 200 freeze–thaw cycles, and tested to failure in four-point bending. Test results were compared with those predicted by theoretical models and reasonable agreement between the tests and the models was obtained. Current design guidelines for FRP-strengthened beams were compared against the test data and were found to be adequate for the artificially aged beams. The test data also indicated that no significant damage to the glass or carbon FRP-strengthened concrete beams had occurred because of freeze–thaw cycling.Key words: concrete, rehabilitation, fibre reinforced polymers, FRP, beams, freeze–thaw, cold region engineering, flexure, external strengthening.

scholarly journals RETROFITTING OF REINFORCED CONCRETE BEAMS USING FIBRE REINFORCED POLYMER (FRP) COMPOSITES – A REVIEW

2013 ◽  
pp. 164-175 ◽  
Author(s):  
Namasivayam Aravind ◽  
Amiya K. Samanta ◽  
D. K. Singha Roy ◽  
Joseph V. Thanikal
Keyword(s):  
Reinforced Concrete ◽  
Life Span ◽  
Structural Engineering ◽  
Concrete Beams ◽  
High Strength ◽  
Reinforced Concrete Beams ◽  
Advanced Materials ◽  
Rc Structures ◽  
Reinforced Polymer ◽  
Fibre Reinforced Polymer

Rehabilitation and strengthening of old structures using advanced materials is a contemporary research in the field of Structural Engineering. During past two decades, much research has been carried out on shear and flexural strengthening of reinforced concrete beams using different types of fibre reinforced polymers and adhesives. Strengthening of old structures is necessary to obtain an expected life span. Life span of Reinforced Concrete (RC) structures may be reduced due to many reasons, such as deterioration of concrete and development of surface cracks due to ingress of chemical agents, improper design and unexpected external lateral loads such as wind or seismic forces acting on a structure, which are also the reasons for failure of structural members. The superior properties of polymer composite materials like high corrosion resistance, high strength, high stiffness, excellent fatigue performance and good resistance to chemical attack etc., has motivated the researchers and practicing engineers to use the polymer composites in the field of rehabilitation of structures. This paper reviews fourteen articles on rehabilitation of reinforced concrete (RC) beams. The paper reviews the different properties of Glass Fibre Reinforced Polymer (GFRP) and Carbon Fibre Reinforced Polymer (CFRP) composites and adhesives, influence of dimensions of beams and loading rate causing failure. The paper proposes an enhanced retrofitting technique for flexural members and to develop a new mathematical model.

scholarly journals Fibre-reinforced polymer strengthening of substandard lap-spliced reinforced concrete members: A comprehensive survey

2016 ◽  
Vol 20 (6) ◽  
pp. 976-1001 ◽  
Author(s):  
Reyes Garcia ◽  
Maurizio Guadagnini ◽  
Kypros Pilakoutas ◽  
Luis A Pech Poot
Keyword(s):  
Reinforced Concrete ◽  
Cost Effective ◽  
Design Guidelines ◽  
Testing Procedures ◽  
Concrete Members ◽  
Reinforced Polymer ◽  
Comprehensive Survey ◽  
Fibre Reinforced Polymer ◽  
Frp Strengthening ◽  
Analytical Approaches

Externally bonded Fibre Reinforced Polymer (FRP) confinement is extensively used to improve the bond strength of substandard lap spliced steel bars embedded in reinforced concrete (RC) components. However, the test results from bond tests on such bond-deficient components are not fully conclusive, which is reflected in the few design guidelines available for FRP strengthening. For the first time, this article presents a comprehensive survey on FRP strengthening of substandard lap-spliced RC members, with emphasis on the adopted experimental methodologies and analytical approaches developed to assess the effectiveness of FRP in controlling bond-splitting failures. The main findings and shortcomings of previous investigations are critically discussed and further research needs are identified. This review contributes towards the harmonisation of testing procedures so as to facilitate the development of more accurate predictive models, thus leading to more cost-effective strengthening interventions.

A review on experimental flexural cracking in FRP reinforced concrete members

2019 ◽  
Author(s):  
Cristina Barris ◽  
Paula Zubillaga ◽  
Lluis Torres
Keyword(s):  
Reinforced Concrete ◽  
Crack Width ◽  
Design Guidelines ◽  
Flexural Members ◽  
Concrete Members ◽  
Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Maximum Crack ◽  
The Relationship ◽  
Frp Bars

<p>This paper aims to assess the relationship among crack width and several influencing parameters of Fibre Reinforced Polymer (FRP) Reinforced Concrete (RC) flexural members. A database with the results of 133 concrete specimens reinforced with different types of FRP bars available in the literature has been collected and analysed. A bond coefficient <i>k</i>b has been adjusted for the maximum crack width of all specimens by using ACI-440 and ISIS Canada design guidelines in the service range, obtaining a mean bond coefficient of 1.11 and 0.72, respectively. The effect of the surface treatment and modulus of elasticity of the FRP rebar, and the <i>n·</i> ratio on the bond coefficient have been studied, obtaining no significant influence of the studied parameters due to the high scatter of results.</p>

Behaviour of reinforced GFRP bars concrete beams having strengthened splices using CFRP sheets

2021 ◽  
pp. 136943322110015
Author(s):  
Akram S. Mahmoud ◽  
Ziadoon M. Ali
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
New Method ◽  
Gfrp Bars ◽  
Reinforced Polymer ◽  
Strength Capacity ◽  
Cfrp Sheet ◽  
Carbon Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer

When glass fibre-reinforced polymer (GFRP) bar splices are used in reinforced concrete sections, they affect the structural performance in two different ways: through the stress concentration in the section, and through the configuration of the GFRP–concrete bond. This study experimentally investigated a new method for increasing the bond strength of a GFRP lap (two GFRP bars connected together) using a carbon fibre-reinforced polymer (CFRP) sheet coated in epoxy resin. A new splicing method was investigated to quantify the effect of the bar surface bond on the development length, with reinforced concrete beams cast with laps in the concrete reinforcing bars at a known bending span length. Specimens were tested in four-point flexure tests to assess the strength capacity and failure mode. The results were summarised and compared within a standard lap made according to the ACI 318 specifications. The new method for splicing was more efficient for GFRP splice laps than the standard lap method. It could also be used for head-to-head reinforcement bar splices with the appropriate CFRP lapping sheets.

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.

Sign in / Sign up

Export Citation Format

Share Document