Effects of damage on the acoustic effectiveness of noise barriers
The installation of noise barriers is a proven measure to protect built-up areas from unwanted noise pollution. During the course of their life cycle, however, various causes can lead to different types of damage. On behalf of the Federal Highway Research Institute (BASt), the Gesellschaft für Akustikforschung Dresden mbH therefore investigated the conditions under which the acoustic effectiveness of the sound barrier will be impaired.
Within the framework of a fundamental literature study, previous findings on the effects of construction and ageing damage on the acoustic effectiveness of noise barriers were collected and evaluated. After a comprehensive analysis of actual damage, types of damage were classified. Based on an extended model for describing the damage, sound field simulations and propagation calculations were carried out. The results were verified with test noise barriers. In-situ measurements of sound insulation and sound absorption on real, damaged noise barriers confirmed the developed calculation model.
In addition, a catalogue has been drawn up which specifically describes the influence of specific damage on the reduction of sound insulation and sound absorption. On this basis, targeted and cost-efficient measures can be taken in future to ensure long-term noise protection.