Title:
Use of CFRP Rebars as Retrofitting System for Masonry Panels
Author(s):
F. Ferretti, A. R. Tilocca, A. Incerti, S. Barattucci, and M. Savoia
Publication:
Symposium Paper
Volume:
360
Issue:
Appears on pages(s):
413-422
Keywords:
Experimental tests; Fiber Reinforced Polymers; Masonry; Pultruded bars; Shear behaviour; Structural strengthening.
DOI:
10.14359/51740640
Date:
3/1/2024
Abstract:
In the last decades, the devastating effects of earthquake events in seismic prone regions increased the attention on the vulnerability of existing constructions. Masonry walls especially experienced severe damage, both considering out-of-plane and in-plane mechanisms. To increase their resistance to horizontal forces, different strengthening systems can be applied. The objective of the present work is to study the efficiency of an innovative strengthening solution, involving the use of fiber reinforced polymer (FRP) pultruded bars. An experimental campaign is presented, in which clay-brick single-leaf masonry panels are retrofitted by carbon FRP rebars, inserted into grooves cut within the masonry panel with a cementitious mortar, and CFRP sheets applied on the panel external surfaces. A total of seven direct shear tests (ST) and four diagonal compression tests (DC) were performed on unreinforced and strengthened samples. The results of the tests showed that the strengthening technique can be effective for the improvement of the shear sliding and diagonal cracking resistances, also allowing to deepen the knowledge of the principal failure mechanisms characterizing the FRP-retrofitted masonry elements.
Related References:
1. CNR-DT 200, Guide for the design and construction of externally bonded FRP systems for strengthening existing structures, National Research Council, Rome, Italy, 2004.
2. CNR-DT 215, Linea Guida per la identificazione, la qualificazione ed il controllo di accettazione di compositi fibrorinforzati a matrice inorganica (FRCM) da utilizzarsi per il consolidamento strutturale di costruzioni esistenti, Consiglio Superiore dei Lavori Pubblici, Servizio Tecnico Centrale, Rome, Italy, 2018.
3. C. Faella, E. Martinelli, E. Nigro, S. Paciello. Shear capacity of masonry walls externally strengthened by a cement-based composite material: An experimental campaign. Constr Build Mater 24 (2010) 84-93.
4. A. Incerti, F. Ferretti, C. Mazzotti, FRCM strengthening systems efficiency on the shear behavior of pre-damaged masonry panels: an experimental study, J Build Rehabil 4, 14 (2019), doi: 10.1007/s41024-019-0053-9
5. S. Babaeidarabad, F. De Caso, A. Nanni, Out-of-plane behavior of URM walls strengthened with Fabric-Reinforced Cementitious Matrix Composite, J Compos Constr 18 (2014), doi: 10.1061/(ASCE)CC.1943-5614.0000457
6. F. Ferretti, A. Incerti, A.R. Tilocca, C. Mazzotti, In-Plane Shear Behavior of Stone Masonry Panels Strengthened through Grout Injection and Fiber Reinforced Cementitious Matrices, Int J Archit Heritage 15(10) (2021) 1375-1394, doi: 10.1080/15583058.2019.1675803
7. A. Bellini, A. Incerti, M. Bovo, C. Mazzotti, Effectiveness of FRCM reinforcement applied to masonry walls subject to axial force and out-of-plane loads evaluated by experimental and numerical studies, Int J Archit Heritage 12(3) (2018) 376-394.
8. F. Ferretti, C. Mazzotti, FRCM/SRG strengthened masonry in diagonal compression: experimental results and analytical approach proposal, Constr Build Mater 283 (2021) 122766, doi: 10.1016/j.conbuildmat.2021.122766
9. F. Ferretti, A.R. Tilocca, A. Incerti, C. Mazzotti, M. Savoia, Effects of thermal variations on the tensile behavior of FRCM strengthening systems, Journal of Composites for Constructions, 26(5) (2022) 04022067, doi: 10.1061/(ASCE)CC.1943-5614.0001241
10. F. Ferretti, M. Canestri, C. Mazzotti, Effect of temperature variations on the bond behavior of FRCM applied to masonry, Materials and Structures, 55(6) (2022) 166, doi: 10.1617/s11527-022-02002-x
11. G. Marcari, G. Manfredi, A. Prota, M. Pecce, In-plane shear performance of masonry panels strengthened with FRP, Composites Part B: Engineering, 38(7–8) (2007) 887-901, doi: 10.1016/j.compositesb.2006.11.004
12. H. Mahmood, J.M. Ingham, Diagonal Compression Testing of FRP-Retrofitted Unreinforced Clay Brick Masonry Wallettes, Journal of Composites for Construction, 15(5) (2011), doi: 10.1061/(ASCE)CC.1943-5614.0000209
13. E. Martinelli, F. Perri, C. Sguazzo et al., Cyclic shear-compression tests on masonry walls strengthened with alternative configurations of CFRP strips, Bullet of Earthquake Engineering 14 (2016) 1695–1720. DOI:10.1007/s10518-016-9895-6
14. R. Capozucca, E. Magagnini, Experimental response of masonry walls in-plane loading strengthened with GFRP strips, Composite Structures, 235 (2020) 111735, doi: 10.1016/j.compstruct.2019.111735
15. R. B. Petersen, M. J. Masia, R. Seracino, In-plane shear behavior of masonry panels strengthened with NSM CFRP strips: Experimental investigation, Journal of Composites for Construction, 14(6) (2010) 754–763, doi: 10.1061/(ASCE)CC.1943-5614.0000134
16. V. Turco, S. Secondin, A. Morbin, M.R. Valluzzi, C. Modena, Flexural and shear strengthening of un-reinforced masonry with FRP bars, Composites Science and Technology, 66(2) (2006) 289-296, doi: 10.1016/j.compscitech.2005.04.042
17. N. Galati, J. G. Tumialan, A. Nanni, Strengthening with FRP bars of URM walls subject to out-of-plane loads, Construction and Building Materials 20 (1–2) (2006) 101–110, doi: 10.1016/j.conbuildmat.2005.06.047
18. P. Yu, P. Silva, A. Nanni, Bond Behavior of Near-Surface Mounted FRP Bars to Masonry, Journal of Composites for Construction, 22(4) (2018), doi: 10.1061/(ASCE)CC.1943-5614.0000857