Title:
Reliability of Compression-Controlled FRP RC Flexural Members Designed using North American Codes and Standards: Comparison and FRP Material Resistance/Strength Reduction Factor Calibration
Author(s):
Fadi Oudah and Adam Hassan
Publication:
Symposium Paper
Volume:
356
Issue:
Appears on pages(s):
120-130
Keywords:
structural reliability; reliability-based design; FRP; buildings; bridges; CSA-S6; CSA-S806; ACI440.1R
DOI:
10.14359/51737251
Date:
10/1/2022
Abstract:
The use of fiber-reinforced polymer (FRP) in structural engineering applications is challenged by the need for increasing the market competitiveness of FRP as compared with conventional reinforcing materials. The market competitiveness of FRP can be enhanced by optimizing the design provisions of FRP-reinforced concrete elements in relevant design codes and standards using structural reliability methods. The objectives of this research are to (1) evaluate and compare the reliability of compression-controlled flexural concrete members reinforced internally using FRP and designed using the Canadian Highway Bridge Design Code (CSA-S6-19), the Design and Construction of Building Structures with Fibre-reinforced Polymers Standard (CSA-S806-17), and Design and Construction of Structural Concrete Reinforced with FRP bars Guideline (ACI440.1R-15); and (2) recommend FRP material resistance factor and strength reduction factor for the respective codes/standards based on a unified target reliability approach. Reliability analysis using Monte Carlo simulation indicates that the reliability index associated with a flexural design using ACI440.1R-15 is about 20% greater than the average reliability index of similar beam and slab sections designed using CSA S6-19 and CSA S806-17 (equates to 150 times greater probability of failure for sections designed using CSA S6 and CSA S806). The recommended material resistance factors for CSA S6 and CSA S806 and the strength reduction factor for ACI 440.1R based on the reliability analysis conducted in this research are 0.80, 0.85, and 0.75, respectively, for a unified target reliability indexes of 4.0 and 3.1 for beams and slabs, respectively. Structural designs based on the recommended values yield consistent reliability indexes among the three codes/standards.
Related References:
1. Shield, C. K., Galambos, T. V., and Gulbrandsen, P., 2011, “On the history and reliability of the flexural strength of FRP
reinforced concrete members in ACI440.1R,” ACI Special Publication, V. 275, pp. 1-18.
2. Allen, D. E., 1975, “Limit states design – a probabilistic study,” Canadian Journal of Civil Engineering, V. 2, No. 1, pp. 36-40.
3. CSA S6, 2019, “Canadian Highway Bridge Design Code,” Canadian Standards Association, Mississauga, Ontario.
4. CSA S806, 2017, “Design and Construction of Building Structures with Fibre-Reinforced Polymers,” Canadian Standards Association, Mississauga, Ontario.
5. ACI 440.1R, 2015, “Guide for the Design and Construction of Structural Concrete Reinforced with Fiber-Reinforced Polymer (FRP) Bars,” Farmington Hills, MI: American Concrete Institute.
6. Benmokrane, B., Brown, V. L., Ali, A. H., Mohamed, K., and Shield, C., 2020, “Reconsideration of the environmental reduction factor CE for GFRP reinforcing bars in concrete structures,” Journal of Composite for Construction, V. 24, No. 4,
06020001.
7. Commentary to CSA S6, 2019, “Canadian Highway Bridge Design Code,” Canadian Standards Association, Mississauga, Ontario.
8. NBCC, 2015, “National Building Code of Canada,” National Research Council, Ottawa, Ontario.
9. ACI 318, 2019, “Building Code Requirements for Structural Concrete,” Farmington Hills, MI: American Concrete Institute.
10. Buckland, P. G., 1981, “Recommended design loads for bridges,” ASCE Journal of Structural Division, V. 107, No. 7, pp.
1161-1213.
11. Christisen, J. T., 1985, “1985 traffic volumes and loadings on primary highway 2:30,” Alberta Research Council, Edmonton,
Alberta, Report No. H7E 85/03.
12. Bartlett, F. M., Hong, H. P., and Zhou, W., 2003, “Load factor calibration for the proposed 2005 edition of the National
Building Code of Canada: Statistics of loads and load effects,” Canadian Journal of Civil Engineering, V. 30, No. 2, pp. 429-
439.
13. Szerszen, M. M., and Nowak, A. S., 2003, “Calibration of design code for buildings (ACI 318): Part 2 – Reliability analysis and resistance factors,” ACI Structural Journal, V. 100, No. 3, pp. 383-391.
14. Nowak, A. S., and Szerszen, M. M., 2003, “Calibration of design code for buildings (ACI 318): Part 1 – Statistical models for resistance,” ACI Structural Journal, V. 100, No. 3, pp. 377-382.
15. MacGregor, J. G., Kennedy, D. J. L, Bartlett, F. M., Chernenko, D., Maes, M. A., and Dunaszegi, L., 1997, “Design criteria and load resistance factors for the Confederation bridge,” Canadian Journal of Civil Engineering, V. 24, No. 6, pp. 882:897.
16. Nowak, A. S., and Collins, K. R., 2012, “Reliability of Structures,” McGraw-Hill, Boston, USA.
17. Desayi, P., and Krishnan, S., 1964, “Equation for the Stress-Strain Curve of Concrete,” ACI Journal, Proceedings V. 61, No. 3, Mar. 1964, pp. 345-350.
18. Truong, V. H., and Kim, S. E., 2017, “An efficient method of system reliability analysis of steel cable-stayed bridges,”
Advances in Engineering Software, V. 114, pp. 295-311.
19. Alhashmi, A. E., Oudah, F., and El Naggar, M. H., 2021, “Application of binomial system-based reliability in optimizing
resistance factor calibration of redundant pile groups,” Computers and Geotechnics, V. 129, 103870.
20. Huang, X., Sui, L., Xing, F., Zhou, Y., and Wu, Y., 2019, “Reliability assessment for flexural FRP-strengthened reinforced
concrete beams based on importance sampling,” Composites Part B, V. 156, pp. 378-398.