Abstract
The coefficient of thermal expansion of fiber reinforced polymer (FRP) in transverse direction is 3–8 times greater than that of hardened concrete. This thermal incompatibility between FRP bar and concrete in transverse direction may cause circumferential cracks within concrete at FRP bar/concrete interface under low temperatures and eventually the debonding of FRP bar from concrete. This paper presents numerical analysis using ADINA finite element software to investigate the thermal behavior of concrete cylinders reinforced with glass FRP bar (GFRP) in cold regions. The non-linear numerical results show that the first circumferential cracks occur within concrete at FRP bar/concrete interface at thermal loads ΔT cr varied between −35 and −25°C for GFRP bar-reinforced concrete cylinders having a ratio of concrete cover thickness to FRP bar diameter (c/d b) varied from 0.8 to 3.6 and a concrete tensile strength of 4.1 MPa. The numerical radial tensile stresses in concrete at the interface compared with those predicted from the analytical model are similar until the appearance of the circumferential cracks in concrete whose analytical results are greater. The ratio c/d b has no significant effect on the transverse thermal strains at FRP bar/concrete interface and also at external surface of concrete cover for a ratio of c/d b ≥ 1.5. Also, the transverse thermal strains, at external surface of concrete cover, predicted from non-linear numerical model are in good agreement with those obtained from the linear analytical model and experimental tests.
Similar content being viewed by others
Abbreviations
- a :
-
Radius of FRP bar
- b :
-
Radius of concrete cylinder
- c :
-
Concrete cover thickness
- d b :
-
Bar diameter
- CTE:
-
Coefficient of thermal expansion
- E c :
-
Modulus of elasticity of concrete
- E l :
-
Longitudinal modulus of elasticity of FRP bar
- E t :
-
Transverse modulus of elasticity of FRP bar
- \({f^{\prime}_{{\rm c}28}}\) :
-
Compressive strength of concrete
- f ct28:
-
Tensile strength of concrete
- f fu :
-
Ultimate tensile strength of FRP bar
- P :
-
Radial pressure exerted by surrounding concrete on FRP bar
- r :
-
Ratio of radius of cylinder to that of FRP bar r = b/a
- α c :
-
Coefficient of thermal expansion of concrete
- α l :
-
Longitudinal coefficient of thermal expansion of FRP bar
- α t :
-
Transverse coefficient of thermal expansion of FRP bar
- ΔT :
-
Temperature variation (thermal load)
- ΔT cr :
-
Thermal load producing the first circumferential cracks in concrete at FRP bar/concrete interface
- \({\varepsilon_{{\rm ct}}}\) :
-
Circumferential strains in concrete
- \({\varepsilon_{{\rm ft}}}\) :
-
Circumferential strains in FRP bar
- ν c :
-
Poisson’s ratio of concrete
- ν tt :
-
Transverse Poisson’s ratio of FRP bar
- ν lt :
-
Longitudinal Poisson’s ratio of FRP bar
- σ ρ :
-
Radial tensile stress
- σ t :
-
Circumferential compressive stress
References
Erki M.A., Rizkalla S.H.: FRP Reinforcement for Concrete Structures. Concret. Int. Design Constr 15, 48–53 (1993)
Nanni A.: Fiber-Reinforced-Plastic (FRP) Reinforcement for Concrete Structures: Properties and Applications, Developments in Civil Engineering, vol. 42. Elsevier Science Publishers, Amsterdam (1993)
Benmokrane, B.; El-Salakawy, E.: Proceedings of third International Conference on Durability and Field Applications of Fibre Reinforced Polymer (FRP) Composites for Construction, CDCC-07, Quebec City, Quebec, Canada (2007)
Zaidi A., Masmoudi R.: Thermal effect on Fiber reinforced polymer reinforced concrete slabs. Can. J. Civil Eng. NRC Canada 35, 312–320 (2008)
Masmoudi R., Zaidi A., Gérard P.: Transverse Thermal Expansion of FRP bars Embedded in Concrete. J. Compos. Constr. ASCE 9, 377–387 (2005)
Gentry T.R., Husain M.: Thermal compatibility of concrete and composite reinforcements. J. Compos. Constr. 3, 82–86 (1999)
Chaallal O., Benmokrane B.: Physical and mechanical performance of innovative glass fiber reinforced plastic rod for concrete and grouted anchorages. Can. J. Civil Eng 20, 254–268 (1993)
American Society for Testing and Materials. Standard test method for splitting Tensile strength of cylindrical concrete specimens. Annual Book Of Astm Standards ASTM C, 496-96, USA, vol. 04.2, pp. 281–284 (2002)
American Society for Testing and Materials. Standard test method for compressive strength of cylindrical concrete specimens. Annual Book Of Astm Standards ASTM C 39/C 39 M–01, USA, vol. 4.2, pp. 21–25 (2002)
Canadian Standards Association. Design and construction of building components with fiber-reinforced polymers. CAN/CSA–S806–02, Toronto, Ontario, Canada (2002)
Gay D.: Matériaux composites 4e édition. Hermès, Paris, France (1997)
Aiello M.A., Focacci F., Nanni A.: Effects of thermal loads on concrete cover of fiber reinforced polymer reinforced elements: theoretical and experimental analysis. ACI Mater. J. 98, 332–339 (2001)
Rahman, H.A.; Kingsley, C.Y.; Taylor, D.A.: Thermal stress in FRP reinforced concrete. In: Proceedings of the Annual Conference of the Canadian Society for Civil Engineering, CSCE, Ottawa, pp. 605–614 (1995)
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Zaidi, A., Masmoudi, R. Numerical Analysis of Thermal Behavior of Concrete Cover Around FRP-Bars in Cold Region. Arab J Sci Eng 37, 489–504 (2012). https://doi.org/10.1007/s13369-012-0173-x
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s13369-012-0173-x