No abstract

No abstract

Dynamic stiffness of resilient materials used as underlayer in floating floors give useful knowledge on the acoustical behaviour of a floor in impact sound insulation. In previous works the influence of the static load and the compressive behaviour of the resilient layers on dynamic stiffness evaluation has been shown. A new measurement technique of the airflow resistance (according to ISO 9053) in terms of static load applied on the resilient materials with open cells is proposed. Usually the airflow resistance of porous materials used as underlayers is evaluated on unloaded samples of material. In dynamic stiffness measurements the material is subject to a static load of 2 kPa. Because the dynamic stiffness value depends on airflow resistivity r [Pa×s/m2] (in particular when 10 kPas/m2< r <100 kPas/m2) through the material, it is important to evaluate the airflow resistivity behaviour in the same condition of the dynamic stiffness measurement, i.e., under a static load of 2 kPa. A new apparatus to evaluate the airflow resistivity in terms of different static loads has been designed and realized at I.N.RI.M. of Turin. The first experimental results show evidence of the dependence of the airflow resistivity of the resilient materials on the applied load.

No abstract

No abstract