The effect of surface treatment of basalt FRP bars on the shear capacity of one-way slabs

The effect of surface treatment of basalt FRP bars on the shear capacity of one-way slabs

1. 2nd International Conference on Civil Infrastructure and Construction (CIC 2023) Prepared by Abathar Al-Hamrani & Dr. Wael Alnahhal Department of Civil and Architectural Engineering - Qatar University The Effect of Surface Treatment of Basalt FRP Bars on the Shear Capacity of One-way Fiber Reinforced Concrete Slabs

2. Outline Introduction Main Objective The Experimental Program Results and discussion Conclusion

3. Introduction and Overview A primary factor leading to extensive degradation……. Corrosion Final Result

4. FRP MATERIAL (CHARACTERISTICS) 1. Higher ultimate tensile strength than steel 2. High strength to weight ratio 3. Excellent resistance to corrosion 4. Electromagnetic neutrality 5. Low thermal conductivity 6. High flexibility

5. FRP MATERIAL (CHARACTERISTICS) Linear elastic behavior to failure Lower elastic modulus than steel No yielding Lower strain at failure Higher initial cost than steel

6. the low Elastic modulus of frp Larger midspan deflection Wider and deeper cracks Reduction in the contribution of: Dowel action Aggregate interlock Uncracked concrete in the compression zone

7. MAIN OBJECTIVE Experimentally study the shear behavior of one-way RC slabs totally reinforced with BFRP bars. - No of tested slabs: 6 slabs - Slab size: 2550 mm length x 600 mm width x 150 mm height

8. Reinforcement types Sand coated BFRP bar Ribbed BFRP bar (a)

9. Distribution of fibers in concrete

10. Testing variables Reinforcement ratio Reinforcement ratio Rho1 = 5 12mm Rho2 = 8 12mm Rho1 = 2 12mm = 0.0064 Rho2 = 4 10mm = 0.01 Rho3 = 4 12mm = 0.0147 Volume fraction of BMF ( Vf ) Type of reinforcement Vf1 = 0% Vf2= 0.75% Ribbed BFRP bars Sand coated BFRP bars Reinforcement ratio Reinforcement ratio Rho1 = 2 12mm = 0.0064 Rho2 = 4 10mm = 0.01 Rho3 = 4 12mm = 0.0147 Volume fraction of BMF ( Vf ) Type of reinforcement Vf1 = 0% Vf2= 0.75% Ribbed BFRP bars Sand coated BFRP bars

11. Testing matrix Specimen No. Bar type Reinforcement ratio % / The volume fraction of BMF% 1 Sand coated 0.792 2.27 2 Ribbed 3 Sand coated 0.75 4 Sand coated 1.27 3.62 5 Ribbed 6 Sand coated 0.75 Specimen No. Bar type The volume fraction of BMF% 1 Sand coated 0.792 2 Ribbed 3 Sand coated 0.75 4 Sand coated 1.27 5 Ribbed 6 Sand coated 0.75

12. test results

13. Load deflection behavior Effect of surface texture

14. Load deflection behavior Effect of reinforcement ratio for ribbed bars Effect of reinforcement ratio for sand-coated bars

15. Load deflection behavior Effect of volume fraction of BMF

16. Fibers bridging the shear crack

17. Load VS shear crack width Effect of surface texture Effect of reinforcement ratio Effect of volume fraction of BMF

18. Load strain behavior Effect of surface texture Effect of reinforcement ratio Effect of fibers addition

19. Failure modes Sandcoated-rho1-plain Ribbed-rho1-plain Sandcoated-rho1-0.75% Sandcoated-rho2-plain Ribbed-rho2-plain Sandcoated-rho2-0.75%

20. CONCLUSION 1- When the reinforcement ratio was increased from rho1 to rho2 , slabs reinforced with SCB bars resulted in a 29% higher shear capacity, while the shear capacity was enhanced by 25% for those reinforced with RB bars. 2- The addition of BMF resulted in a 16.7% gain in the shear capacity for a reinforcement ratio level of 0.792%, whereas their effect was reduced to 4% for a reinforcement ratio level of 1.27%. 3- The cracking load was noticed to be delayed in slabs with a higher reinforcement ratio or with 0.75% of BMF. 4- For counterpart slabs at the same loading level, slabs with a higher reinforcement ratio or with a 0.75% of BMF have shown lower strain values for concrete and BFRP bars at the midspan.

21. CONCLUSION 5 - The slab reinforced with ribbed bars resulted in a higher stiffness and lower midspan deflection than the slab reinforced with sand-coated bars in all loading stages. 6 - The load at the initial flexural crack in the concrete slab with ribbed bars was increased by 22.4% over the counterpart slab with sand-coated bars. 7 - After cracking, the developed strain in the ribbed BFRP bars was notably lower than that in the sand-coated bars up to the ultimate stage. 8- Both slabs failed under shear, however, the shear capacity of the ribbed bars reinforced slab was higher than the sand-coated bars reinforced slab by 6-9%.

22. THANKS FOR YOUR ATTENTION….