1. Home
  2. Vol 10, No 6 (2024)
  3. Cao

Performance of NSM GFRP Retrofitted Postfire RC Slabs Under Monotonic and Cyclic Loadings

Vui Van Cao

Abstract


This study investigated the performance and mechanical properties of NSM GFRP retrofitted postfire RC slabs under monotonic and cyclic loadings. Experiments were conducted for eight RC slabs exposed to different fires. These postfire slabs were retrofitted with NSM GFRP bars, which were then monotonically and cyclically loaded until failure. The results indicated that the control slab failed in flexure, with steel yielding and a main mid-span crack. NSM GFRP retrofitted postfire slabs failed by either crushing of compressive concrete or rupture of GFRP bars. The tested slabs were characterized by bi-linear behavior. NSM GFRP retrofitting improved the yield and ultimate loads of postfire slabs by 47.2% and 116.4% on average, respectively. Fire duration was confirmed to be a main factor that significantly reduced the elastic stiffness of NSM GFRP retrofitted postfire slabs by 60.9% for 60 min of fire. The average plastic-to-elastic stiffness of NSM GFRP retrofitted postfire slabs was 0.132, which was 32 times that of the control slab. The cyclic loading effect caused substantial stiffness degradation of NSM GFRP retrofitted postfire slabs. The average stiffness degradations were 10.6% and 7.2% for original and NSM GFRP retrofitted postfire slabs, respectively. However, the cyclic loading effect caused negligible strength degradation. The combination of increasing fire duration and the cyclic loading effect significantly decreased ductility. Theoretical analyses were carried out to estimate the yield moments of slabs. The analytical equation demonstrated its accuracy in estimating the yield moment capacity of postfire RC slabs without and with NSM GFRP retrofitting.

 

Doi: 10.28991/CEJ-2024-010-06-017

Full Text: PDF


Keywords


Fire; Reinforced Concrete; Slab; NSM; GFRP; Retrofitting.

References


Behnam, B. (2019). Fire Structural Response of the Plasco Building: A Preliminary Investigation Report. International Journal of Civil Engineering, 17(5), 563–580. doi:10.1007/s40999-018-0332-x.

Weerasinghe, P., Nguyen, K., Mendis, P., & Guerrieri, M. (2020). Large-scale experiment on the behavior of concrete flat slabs subjected to standard fire. Journal of Building Engineering, 30. doi:10.1016/j.jobe.2020.101255.

Nguyen, V. N., & Cao, V. Van. (2023). Experimental and Analytical Study on Postfire Reinforced Concrete Beams Retrofitted with CFRP in Flexure and Shear. Civil Engineering Journal (Iran), 9(7), 1610–1629. doi:10.28991/CEJ-2023-09-07-05.

da Costa, L. M., de Carvalho Pires, T. A., & Silva, J. J. R. (2023). Shear strengthening of fire-damaged reinforced concrete beams using NSM CFRP laminates. Engineering Structures, 287, 116175. doi:10.1016/j.engstruct.2023.116175.

El-Hacha, R., & Rizkalla, S. H. (2004). Near-surface-mounted fiber-reinforced polymer reinforcements for flexural strengthening of concrete structures. ACI Structural Journal, 101(5), 717–726. doi:10.14359/13394.

Bilotta, A., Ceroni, F., Nigro, E., & Pecce, M. (2015). Efficiency of CFRP NSM strips and EBR plates for flexural strengthening of RC beams and loading pattern influence. Composite Structures, 124, 163–175. doi:10.1016/j.compstruct.2014.12.046.

De Lorenzis, L., & Teng, J. G. (2007). Near-surface mounted FRP reinforcement: An emerging technique for strengthening structures. Composites Part B: Engineering, 38(2), 119–143. doi:10.1016/j.compositesb.2006.08.003.

Nguyen, V. N., & Van Cao, V. (2023). NSM GFRP Strengthening of Reinforced Concrete Beams after Exposure to Fire: Experiments and Theoretical Model. Journal of Composites for Construction, 27(1). doi:10.1061/jccof2.cceng-3933.

Kara, I. F., Ashour, A. F., & Köroğlu, M. A. (2016). Flexural performance of reinforced concrete beams strengthened with prestressed near-surface-mounted FRP reinforcements. Composites Part B: Engineering, 91, 371-383. doi:10.1016/j.compositesb.2016.01.023.

Nguyen, V. N., & Cao, V. Van. (2023). Performance of Postfire Reinforced Concrete Beams Retrofitted with External Bonded and Near-Surface Mounted CFRP: Experiments and Analyses. Journal of Performance of Constructed Facilities, 37(3), 04023016. doi:10.1061/jpcfev.cfeng-4297.

Yang, J., & Wang, L. (2018). Experimental research on flexural behaviors of damaged PRC beams strengthened with NSM CFRP strips. Construction and Building Materials, 190, 265-275. doi:10.1016/j.conbuildmat.2018.09.109.

Zhang, S. S., Yu, T., & Chen, G. M. (2017). Reinforced concrete beams strengthened in flexure with near-surface mounted (NSM) CFRP strips: Current status and research needs. Composites Part B: Engineering, 131, 30–42. doi:10.1016/j.compositesb.2017.07.072.

Gravina, R., Aydin, H., & Visintin, P. (2018). Review of near-surface mounted FRP plates in the strengthening of continuous flexural members and bond behavior. Australian Journal of Civil Engineering, 16(2), 158–165. doi:10.1080/14488353.2018.1537594.

Al-Saadi, N. T. K., Mohammed, A., Al-Mahaidi, R., & Sanjayan, J. (2019). A state-of-the-art review: Near-surface mounted FRP composites for reinforced concrete structures. Construction and Building Materials, 209, 748–769. doi:10.1016/j.conbuildmat.2019.03.121.

Sabbaghian, M., & Kheyroddin, A. (2020). Flexural strengthening of RC one-way slabs with high-performance fiber-reinforced cementitious composite laminates using steel and GFRP bar. Engineering Structures, 221. doi:10.1016/j.engstruct.2020.111106.

Silva, M. A. L., & Gamage, J. C. P. H. (2020). Combined effects of Carbon Fiber Reinforced Polymer flexural reinforcements and post installed shear dowels on the performance of flat slabs. Composite Structures, 236. doi:10.1016/j.compstruct.2019.111848.

Yazdani, S., Asadollahi, S., Shoaei, P., & Dehestani, M. (2021). Failure stages in post-tensioned reinforced self-consolidating concrete slab strengthened with CFRP layers. Engineering Failure Analysis, 122. doi:10.1016/j.engfailanal.2021.105219.

Kamonna, H. H., & Al-Sada, D. J. A. (2021). Strengthening of one-way reinforced concrete slabs using near surface mounted bars. Materials Today: Proceedings, 42, 1843–1853. doi:10.1016/j.matpr.2020.12.215.

Zheng, X., Wan, B., Huang, P., & Huang, J. (2019). Experimental study of hybrid strengthening technique using carbon fiber laminates and steel plates for reinforced concrete slabs. Construction and Building Materials, 210, 324–337. doi:10.1016/j.conbuildmat.2019.03.100.

Kankeri, P., Suriya Prakash, S., & Pachalla, S. K. S. (2018). Experimental and Numerical Studies on Efficiency of Hybrid Overlay and Near Surface Mounted FRP Strengthening of Pre-cracked Hollow Core Slabs. Structures, 15, 1–12. doi:10.1016/j.istruc.2018.05.003.

Kodur, V. K. R., & Bhatt, P. P. (2018). A numerical approach for modeling response of fiber reinforced polymer strengthened concrete slabs exposed to fire. Composite Structures, 187, 226–240. doi:10.1016/j.compstruct.2017.12.051.

Bilotta, A., Compagnone, A., Esposito, L., & Nigro, E. (2020). Structural behavior of FRP reinforced concrete slabs in fire. Engineering Structures, 221. doi:10.1016/j.engstruct.2020.111058.

Huang, Z. (2010). The behavior of reinforced concrete slabs in fire. Fire Safety Journal, 45(5), 271–282. doi:10.1016/j.firesaf.2010.05.001.

Lim, L., Buchanan, A., Moss, P., & Franssen, J. M. (2004). Numerical modelling of two-way reinforced concrete slabs in fire. Engineering Structures, 26(8), 1081–1091. doi:10.1016/j.engstruct.2004.03.009.

Huang, Z., Burgess, I. W., & Plank, R. J. (2003). Modeling Membrane Action of Concrete Slabs in Composite Buildings in Fire. II: Validations. Journal of Structural Engineering, 129(8), 1103–1112. doi:10.1061/(asce)0733-9445(2003)129:8(1103).

Huang, Z., Burgess, I. W., & Plank, R. J. (2003). Modeling Membrane Action of Concrete Slabs in Composite Buildings in Fire. I: Theoretical Development. Journal of Structural Engineering, 129(8), 1093–1102. doi:10.1061/(asce)0733-9445(2003)129:8(1093).

Huang, Z., Burgess, I. W., & Plank, R. J. (2000). Effective stiffness modelling of composite concrete slabs in fire. Engineering Structures, 22(9), 1133–1144. doi:10.1016/S0141-0296(99)00062-0.

Lim, L., Buchanan, A., Moss, P., & Franssen, J.-M. (2004). Computer Modeling of Restrained Reinforced Concrete Slabs in Fire Conditions. Journal of Structural Engineering, 130(12), 1964–1971. doi:10.1061/(asce)0733-9445(2004)130:12(1964).

Moss, P. J., Dhakal, R. P., Wang, G., & Buchanan, A. H. (2008). The fire behavior of multi-bay, two-way reinforced concrete slabs. Engineering Structures, 30(12), 3566–3573. doi:10.1016/j.engstruct.2008.05.028.

Yu, X., & Huang, Z. (2008). An embedded FE model for modelling reinforced concrete slabs in fire. Engineering Structures, 30(11), 3228–3238. doi:10.1016/j.engstruct.2008.05.004.

Wang, Y., Yuan, G., Huang, Z., Lyu, J., Li, Q., & Long, B. (2018). Modelling of reinforced concrete slabs in fire. Fire Safety Journal, 100, 171–185. doi:10.1016/j.firesaf.2018.08.005.

Azevedo, A. S., Firmo, J. P., Correia, J. R., Firouz, R. M., & Barros, J. A. O. (2023). Fire behavior of reinforced concrete slab strips strengthened with prestressed NSM-CFRP laminates. Engineering Structures, 297. doi:10.1016/j.engstruct.2023.116982.

Rosa, I. C., Santos, P., Firmo, J. P., & Correia, J. R. (2020). Fire behavior of concrete slab strips reinforced with sand-coated GFRP bars. Composite Structures, 244. doi:10.1016/j.compstruct.2020.112270.

Wang, Y., Dong, Y. L., Li, B., & Zhou, G. C. (2013). A fire test on continuous reinforced concrete slabs in a full-scale multi-story steel-framed building. Fire Safety Journal, 61, 232–242. doi:10.1016/j.firesaf.2013.08.005.

Wang, Y., Yuan, G., Huang, Z., Lyv, J., Li, Z. Q., & Wang, T. yan. (2016). Experimental study on the fire behavior of reinforced concrete slabs under combined uni-axial in-plane and out-of-plane loads. Engineering Structures, 128, 316–332. doi:10.1016/j.engstruct.2016.09.054.

Wang, Y., Jiang, Y., Huang, Z., Li, L., Huang, Y., Zhang, Y., Zhang, G., Zhang, X., & Duan, Y. (2021). Post-fire behavior of continuous reinforced concrete slabs under different fire conditions. Engineering Structures, 226. doi:10.1016/j.engstruct.2020.111342.

Gao, W. Y., Hu, K. X., Dai, J. G., Dong, K., Yu, K. Q., & Fang, L. J. (2018). Repair of fire-damaged RC slabs with basalt fabric-reinforced shotcrete. Construction and Building Materials, 185, 79–92. doi:10.1016/j.conbuildmat.2018.07.043.

Sui, Z. A., Dong, K., Jiang, J., Yang, S., & Hu, K. (2020). Flexural behavior of fire-damaged prefabricated RC Hollow slabs strengthened with CFRP versus TRM. Materials, 13(11), 2556. doi:10.3390/ma13112556.

TCVN 7570. (2006). Aggregates for concrete and mortar − Specifications. Vietnam Standard, Hanoi, Vietnam. (In Vietnamese).

ACI 318-19. (2019). Building code requirements for structural concrete. American Concrete Institute (ACI), Michigan, United States.

ACI 440.2R-17. (2017). Guide for the design and construction of externally bonded FRP systems for strengthening concrete structures. American Concrete Institute (ACI), Michigan, United States.

Singh, S. B., Reddy, A. L., & Khatri, C. P. (2014). Experimental and Parametric Investigation of Response of NSM CFRP-Strengthened RC Beams. Journal of Composites for Construction, 18(1), 04013021. doi:10.1061/(asce)cc.1943-5614.0000411.

Kalayci, A. S., Yalim, B., & Mirmiran, A. (2010). Construction tolerances and design parameters for NSM FRP reinforcement in concrete beams. Construction and Building Materials, 24(10), 1821–1829. doi:10.1016/j.conbuildmat.2010.04.022.

Soliman, S. M., El-Salakawy, E., & Benmokrane, B. (2010). Flexural behavior of concrete beams strengthened with near surface mounted fibre reinforced polymer bars. Canadian Journal of Civil Engineering, 37(10), 1371–1382. doi:10.1139/L10-077.

Sharaky, I. A., Selmy, S. A. I., El-Attar, M. M., & Sallam, H. E. M. (2020). The influence of interaction between NSM and internal reinforcements on the structural behavior of upgrading RC beams. Composite Structures, 234. doi:10.1016/j.compstruct.2019.111751.

ASCE/SEI 41-06. (2007). Seismic rehabilitation of existing buildings. American Society of Civil Engineers (ASCE), Reston, United States. doi:10.1061/9780784408841.


Full Text: PDF

DOI: 10.28991/CEJ-2024-010-06-017

Refbacks

  • There are currently no refbacks.


Bookmark and Share


Copyright (c) 2024 Vui Van Cao

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
x
Message