Source-specific sound insulation descriptors for transportation noise and proposal for insulation classes

Abstract

The standard normalized traffic noise spectrum referred in both ISO 717-1 and ISO/TC 43 16717, has been assumed to represent all types of transportation noise sources for rating sound insulation of external building elements. A study aiming to obtain a database about spectral content of railway, aircraft and seaway noise in addition to traffic noise, was conducted within a national project parallel to COST TU 0901. The A-weighted normalized reference spectrums were obtained for each type of source at different operational conditions based on the field measurements on building facades in urban and suburban areas. Statistical analyses revealed that the standard reference spectrum could not represent all type of sources because of the uncertainties at certain third octave bands. The proposed spectrums were applied to ISO/TC 16717-1 procedure to derive the source-specific sound insulation descriptors (R<inf>wt</inf>, R <inf>wa</inf>,R<inf>wr</inf>, R<inf>ws</inf>) . During the study, a survey was performed on common building elements, materials and constructional details and, the insulation performances of 287 sample building elements (of which is 78 external elements) were computed in terms of the new and standard descriptors and the results were compared. As an outcome of the project, the insulation categories were proposed and the class numbers for various descriptors were determined. © 2014 Elsevier B.V., All rights reserved.