Strengthening non-engineered building using vegetal FRCM retrofitting: A numerical modeling approach for seismic assessment

Abstract

The concept of developing alternative rehabilitation techniques to enhance the performance of structures with low seismic resistance has come to light in recent years. Substantial research and methods have been devoted to evolving strengthening techniques worldwide for structures with economic value, with the ultimate goal of enhancing seismic resilience in them. Among these, Fiber Reinforced Cementitious Matrix (FRCM) stands out as a reliable alternative to conventional retrofitting approaches due to its high strength-to-density ratio and negligible mass increment. However, the inadequacy of full-scale modeling and the application of FRCM in building components persist in the research domain. Therefore, this paper aims to develop a numerical model for the full-scale application of vegetal FRCM composites in retrofitting a representative non-engineered building. The full-scale application of the four vegetal FRCM materials (hemp, cotton, flax, and sisal) in 1-ply and 2-ply configurations was undertaken to strengthen a non-engineered building. The results of pushover analysis show that buildings retrofitted with 2-ply hemp and 2-ply flax FRCM exhibited the most significant improvement in base shear strength, with increments of about 30% and 28.5% respectively, compared to the peak base shear of the bare frame. Additionally, the retrofitted models demonstrated an increase in their ductility. A subsequent fragility analysis highlighted a reduction in the seismic hazard vulnerability of the building for the relevant earthquake spectrums. Finally, the results from the numerical analysis confirm that the use of vegetal fibers as cementitious matrix can have significant potential to be an effective and sustainable strengthening technique for seismically deficient buildings.