Evaluating Shear Contribution of FRP To Masonry Walls

Yıl 2023, Cilt: 12 Sayı: 2, 105 - 114, 17.11.2023

Zeynep Ünsal Aslan Metin Karslıoğlu

Öz

In earthquake-prone regions, there has been a notable focus on employing modern and efficient techniques to enhance the durability of unreinforced masonry walls (URM) in recent years. Among these approaches, the utilization of Fiber Reinforced Polymer (FRP) for strengthening has particularly gained recognition. In this paper, a novel empirical model is presented, employing nonlinear regression analysis, to forecast the shear contribution of FRP strips. URM walls with three configurations of the FRP strips have been considered: one is horizontal FRP strips, the second is vertical FRP strips, and the other is FRP grid strips. The proposed model is developed by using the input parameters determined by considering fourteen different experimental specimens available in the literature, and also considers the influence of reinforcement ratio (ρ0), which was not taken into account in previously suggested models. The FRP strips shear contribution of was competed with the ACI 440.7R-10 model and experimental results. The essential step in any analytical model is evaluating the developed model's accuracy by comparing it with the experimental data and model. This evaluation was performed using the coefficient of determination (R2). The results indicated that the suggested model accurately forecasts the shear contribution of FRP strips and is better aligned with experimental results compared to the ACI 440.7R-10 model.

Anahtar Kelimeler

URM, FRP strips, reinforcement ratio, empirical model, horizontal and vertical

Yığma Duvarlarda FRP Kesme Dayanımı Katkısının Değerlendirilmesi

Öz

Son yıllarda deprem bölgelerinde, donatısız yığma duvarların (URM) dayanıklılığını artırmak için modern ve etkili tekniklerin kullanılmasına dikkate değer bir ilgi olmuştur. Bu yaklaşımlar arasında Fiber Takviyeli Polimerin (FRP) güçlendirme amacıyla kullanılması popülerlik kazanmıştır Bu makale, doğrusal olmayan regresyon analizi kullanarak, FRP şeritlerinin kesme dayanımı katkısını tahmin etmek için yeni bir ampirik model tanıtmaktadır. FRP şeritlerinin üç konfigürasyonuna sahip donatısız yığma duvarları dikkate alınmıştır. Bu konfigürasyonlardan biri yatay FRP şeritlerinin, ikincisi dikey FRP şeritlerinin ve diğeri hem yatay hem dikey FRP şeritlerin birlikte bulunduğu konfigürasyondur. Önerilen model, literatürde yer alan on dört farklı deney numunesi dikkate alınarak belirlenen girdi parametreleri kullanılarak geliştirilmiştir. Ayrıca, önerilen modelde literatürde mevcut modellerde dikkate alınmayan güçlendirme oranının (ρ0) etkisi de dikkate alınmıştır. FRP şeritlerin kesme dayanımı katkısı ACI 440.7R-10 modeli ve deneysel sonuçlarla karşılaştırılmıştır. Herhangi bir analitik modelde temel adım, geliştirilen modelin doğruluğunu deneysel veriler ve modelle karşılaştırarak değerlendirmektir. Bu değerlendirme belirleme katsayısı (R2) kullanılarak yapılmıştır. Sonuçlar, önerilen modelin FRP şeritlerin kesme dayanımı katkısını doğru bir şekilde tahmin ettiğini ve ACI 440.7R-10 modeline kıyasla deneysel sonuçlarla daha iyi uyumlu olduğunu göstermiştir.

Anahtar Kelimeler

URM, FRP şeritleri, güçlendirme oranı, ampirik model, yatay ve dikey

Kaynakça

• ACI 440.7R-10, 2010, Guide for the design and construction of externally bonded FRP system for strengthening unreinforced masonry structures, American Concrete Institute.
• Cheng, S., Yin, S., Jing, L., 2020. Comparative experimental analysis on the in-plane shear performance of brick masonry walls strengthened with different fiber reinforced materials. Construction and Building Materials, 259, 120387.
• CNR-DT 200, 2004, Guide for the design and construction of externally bonded FRP systems for strengthening existing structures, Advisory Committee on Technical Recommendations for Construction.
• Doran, B., Ulukaya, S., Unsal Aslan, Z., Karslioglu, M., Yuzer, N., 2021. Experimental Investigation of CFRP Strengthened Unreinforced Masonry Walls with Openings. International Journal of Architectural Heritage.
• Elgawady, M. A., Lestuzzi, P., Badoux, M., 2004. A review of conventional seismic retrofitting techniques for URM. 13th International Brick and Block Masonry Conference, 1–10.
• ElGawady, M., Lestuzzi, P., Badoux, M., 2004. A review of retrofitting of unreinforced masonry walls using composites. 4th International Conference on Advanced Composite Materials in Bridges and Structures, July, 1–8.
• Emami, M., Eftekhar, M. R., Karimizadeh, H., 2018. Experimental study on postponing the deboning of FRP sheets in masonry walls. International Journal of Architectural Heritage. Garbin, E., Galati, N., Nanni, A., Modena, C., Valluzzi, M. R., 2007. Provisional design guidelines for the strengthening of masonry structures subject to in-plane loading. 10th North American Masonry Conference, 458–471. Marcari, G., Manfredi, G., Prota, A., Pecce, M., 2007. In-plane shear performance of masonry panels strengthened with FRP. Composites Part B: Engineering, 38(7–8), 887–901.
• Marcari, G., Oliveira, D. V., Fabbrocino, G., Loureno, P. B., 2011. Shear capacity assessment of tuff panels strengthened with FRP diagonal layout. Composites Part B: Engineering, 42(7), 1956–1965.
• Maria, H. S., Alcaino, P., Luders, C., 2006. Experimental response of masonry walls externally reinforced with carbon fiber fabrics. 8th US National Conference on Earthquake Engineering 2006, 14(February 2014), 8555–8564.
• Marshall, O. S., Sweeney, S. C., Trovillion, J. C., 2000. Performance testing of fiber-reinforced polymer composite overlays for seismic rehabilitation of unreinforced masonry walls.
• Martinelli, E., Perri, F., Sguazzo, C., Faella, C., 2016. Cyclic shear-compression tests on masonry walls strengthened with alternative configurations of CFRP strips. Bulletin of Earthquake Engineering, 14(6), 1695–1720.
• Moon, F. L., Yi, T., Leon, R. T., Kahn, L. F., 2007. Testing of a Full-Scale Unreinforced Masonry Building Following Seismic Strengthening. Journal of Structural Engineering, 133(9), 1215–1226.
• Rahman, A., and Ueda, T., 2016. In-Plane Shear Performance of Masonry Walls after Strengthening by Two Different FRPs. Journal of Composites for Construction, 20(5), 1–14.
• Triantafillou, T., and Antonopoulos, P., 1999. Design of Concrete Flexural Members Strengthened in Shear With FRP. ASCE Journal of Materials in Civil Engineering, 11(4), 325–330.
• Triantafillou, T. C., 1998. Strengthening of Masonry Structures Using Epoxy-Bonded FRP Laminates. Journal of Composites for Construction, 2(2), 96–104.
• Valluzzi, M. R., Tinazzi, D., Modena, C., 2002. Shear behavior of masonry panels strengthened by FRP laminates. Construction and Building Materials, 16(7), 409–416.
• Vega, C., Torres, N., 2018. External strengthening of unreinforced masonry walls with polymers reinforced with carbon fiber. Ingeniería e Investigación, 38(3), 15-23.
• Wang, Q., Chai, Z., Huang, Y., Yang, Y., Zhang, Y., 2006. Seismic shear capacity of brick masonry wall reinforced by GFRP. Asian Journal of Civil Engineering (Building and Housing), 7(6), 563–580.