Dynamic stiffness characteristics of resilient materials for remodelling of the aged apartment buildings

This study investigates dynamic stiffness characteristics of floor resilient materials for reduction of floor impact noises in remodelled aged apartment buildings. Since the aged apartment buildings built in before 2005 have too thin floor structure system, relatively thinner thickness less than 30 mm with lower dynamic stiffness is required for resilient materials to secure the maximum inner height of the room. In addition, dynamic stiffness in after-heating condition should be also examined because resilient materials are exposed to repeated thermal variations due to the Korean-style floor-heating system. Common resilient materials with various thickness and component such as EPS or EVA were collected, then dynamic stiffness was measured according to KS F 2868 and ISO 9052-1 before and after 48 hours heating with 70 degrees Celsius. As results, range of dynamic stiffness values of resilient materials in before- and after-heating conditions was derived as a function of materials' thickness and composition. Base on the measurement results, the suitable range of dynamic stiffness and composition were suggested according to thickness range. In addition, time-dependent tendencies of dynamic stiffness of resilient materials in after-heating condition were discussed for improving standard test procedure.