PSI - Issue 37

Sonia Djenad et al. / Procedia Structural Integrity 37 (2022) 321–329 Djenad et al / Structural Integrity Procedia 00 (2019) 000 – 000

328

8

a)

b)

35

10 15 20 25 30 35 40

Unconfined

5CS4E2 5CS4E3

Unconfined

3CS3E1 3CS3E3

5CS4E1 5CS4E4

30

3CS3E2 3CS3E4

25

20

15

Stress (Mpa)

Stress (Mpa)

10

5

0 5

0

0

0,002

0,004

0,006

0,008

0,01

0

0,002

0,004

0,006

0,008

0,01

Strain

Strain

Fig. 5. Stress-Strain response according to FRP Strips thickness: (a) 03 FRP Strips; (b) 05 FRP Strips

5. Conclusion The main objective of this investigation is to study the nonlinear behaviour concrete cylinders partially-confined by externally bonded FRP stirrups under axially compressive loading using ABAQUS software. Numerical results analysis in terms of stress vs. axial strain response allowed us to draw the following conclusions: • Partially confinement using bonded FRP Strips improves considerably the compressive strength and ductility of concrete under compressive loading; • FRP Strips spacing and stacking allow to oppose to the radial deformations with no effect on the global behavior and the failure modes of confined concrete, • FRP Strips width increasing leads to a passage from softening behavior is hardening one, which improve the average resistance of concrete due to strain-hardening effects in the stage preceding confined concrete rupture. Despite the encouraged obtained results, more experiments and numerical simulations are necessary to draw complete conclusions about the interest of FRP partially confined concrete. Indeed, Further works should validate the different results obtained by own-test results, also the authors recommend to carefully making slip models in simulations to ensure an optimal adhesion in the bonded interface. References H. Saadatmanesh, M. R. Ehsani, and M. W. Li “Strength and Ductility of Concrete Columns Externally Reinforced with Fiber Composite Straps ACI STRUCTURAL», JOURNALV. 91, No. 4 July-August 1994. G. Wu, Z.T. Lu¨, Z.S. Wu «Strength and ductility of concrete cylinders confined with FRP composites Construction and Building Materials » 20 134 – 148, 2006 F. Bentayeb, K. Ait Tahar, A. Chateauneuf “New technique for reinforcement of concrete columns confined by embedded composite grid. Constr Build Mate (2008); 22: 1624–1633. A. Si Salem, S. Ait Taleb and K. Ait tahar « Experimental and statistical investigation of a new concrete-composite beam with encased polymer tube wrapped by FRP »; Frontiers of Structural and Civil Engineering, 9(2): 154-162 (2015) S. Ait Taleb, A. Si Salem, and K. Ait tahar “Behaviour of a new graded beam reinforced with externally bonded composite sheets”, European Journal of Environmental and Civil Engineering 21(9), 2016 pp. 1171-1185 Lee, J, G.L. Fenves «Plastic-damage model for cyclic loading of concrete structures » Journal of Engineering Mechanics (1998), 124 (8), pp. 892 900 J. Lubliner,. Oliver, S. Oller and E. Onate « A plastic-damage model for concrete » International Journal Solids Structures 25(3), 1989, 299-326 S. Oller, E. Onate, J. Oliver, and J. Lubliner « Finite element nonlinear analysis of concrete structure using a plastic-damage model » Engineering Fracture Mechanics, vol. 35, pp. 219-231, 2001 Jiong-Feng Liang, Wan-Jie Zou, Zeng-Liang Wang, Da-wei Liu. Compressive behavior of CFRP-confined partially encased concrete columns under axial loading Composite Structures 229 (2019) 111479