Speaker
Description
This contribution summarizes the results of multi-year research focused on the integration of biobased blown-in insulation materials, such as straw and cellulose, into building structures, with an emphasis on their acoustic properties. Although initial studies confirmed the environmental sustainability and satisfactory sound reduction index of these constructions, they simultaneously revealed critical limitations of the current ISO 9052-1 normative methodology. The standardized load (4kPa) applied during dynamic stiffness (s’) measurements causes excessive compression of these materials, leading to a significant overestimation of stiffness and subsequent errors in acoustic predictions. The core of this work presents a methodology utilizing a two-degree-of-freedom (2-DOF) system and a lightweight load plate. To atenuate nonlinear response of the lightweight plate during top-down excitation, a baseplate excitation system (bottom-up) was implemented. The mechanical behavior of the porous structure under low loading conditions was analyzed using Kraak's Extended Model (KEM) and validated through numerical simulations (FEM and Simscape).