Seismic response characteristics of fiber reinforced concrete

Abstract

Seismic events have consistently caused substantial damage to civil infrastructure, emphasizing the need for structural systems with enhanced resilience and energy dissipation capacity. Since concrete is the most widely used construction material in the building industry and the second most consumed substance worldwide after water, its performance under seismic loading is of particular importance. However, conventional concrete exhibits several inherent limitations, including brittleness, low tensile strength, and limited energy absorption capacity. These shortcomings reduce its ability to withstand dynamic and seismic actions, thereby increasing the vulnerability of concrete structures during strong earthquakes. To improve the ductility, crack resistance, and energy dissipation capacity of concrete structures, Fiber-Reinforced Concrete (FRC) has been developed by incorporating various types of fibers, including steel, glass, polypropylene (PP), and carbon fibers, within the concrete matrix. Several studies have investigated FRC for seismic applications; however, this work focuses on a comparative assessment of key parameters governing the behavior of hybrid fiber systems under realistic conditions. The novelty of this study lies in the evaluation of mono and hybrid fiber configurations subjected to two major Moroccan earthquakes, namely the 2004 Al Hoceima and 2023 Al Haouz events, providing a realistic seismic framework. In addition, the structural response is computed using a fourth-order Runge–Kutta (RK4) method, which is rarely employed in nonlinear seismic analysis of such systems. This study investigates the seismic behavior of a three-story reinforced concrete (RC) building incorporating different fibers. Both mono-fiber and hybrid-fiber mixtures are considered, with fiber volume fractions (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$V_f$$\end{document}) ranging from 0.5 to 2.5%. Numerical simulations are performed to evaluate the dynamic response of the structure under seismic excitation. The results indicate that steel fibers primarily enhance stiffness and strength, whereas PP fibers improve energy dissipation and damping capacity. Furthermore, hybrid fiber combinations provide a more balanced structural response by combining the advantages of different fiber types. Overall, the study demonstrates that the appropriate selection of fiber type, volume fraction, and hybridization strategy can significantly enhance the seismic resilience, energy dissipation capacity, and overall dynamic performance of concrete structures.