Tuned mass dampers for improving the sustainability and resilience of seven reinforced concrete chimneys under environmental loads

In the late 1950s, driven by economic development and environmental considerations, industrial plants began utilizing reinforced concrete (RC) for chimney construction, lacking specific earthquake-resistance provisions. However, RC chimneys exhibit an inelastic response and a potential for brittle collapse under seismic loads. The reconstruction of these chimneys presents a challenge, considering their significant symbolic value within the community and the increasing focus on sustainability, material recycling, and environmental resilience. In response to this need, we explore the performance of seven historic RC chimneys retrofitted with Tuned Mass Dampers (TMDs). This study considers the nonlinear material properties of concrete and steel rebars subjected to five European earthquakes. The TMDs’ effectiveness is evaluated by their impact on top displacement, base shear, and base moment. Additional aspects, such as equivalent damping and mode changes, are scrutinized. Through a parametric investigation, we analyze the influence of slenderness ratio, taper ratio, height, and vertically distributed mass on chimney response to earthquakes. Notably, the slenderness ratio emerges as a crucial factor affecting mass ratio, optimizing TMD parameters, base shear, and base moment. Notably, geometric characteristics seem to exert minimal influence on equivalent damping. Additionally, examining energy dissipated by TMDs reveals their contribution to increased elastic damping energy in chimneys, concurrently reducing kinetic and hysteretic (inelastic) energies. Elastic damping energy involves dissipation through inherent system elasticity, while hysteretic damping encompasses energy dissipation due to material damping effects. This research sheds light on the potential of TMDs in enhancing the seismic resilience of historic RC chimneys and provides insights into the key parameters influencing their performance.