Characterisation, performance and conceptionof vented and absorptive road covers

摘要

A promising solution for road traffic noise abatement is the use of vented absorptive covers (also known as louvred covers). It is especially dedicated to platforms in a trench orwhen high barriers placed on each side are not sufficient to reduce the sound level at receiver down toa maximum acceptable threshold. In the present paper a parametric survey has been carried out usingMICADO, a 2D Boundary Element Method (BEM) code developed at CSTB. The aim is to determine the vented cover performance as a function of height and inclination of baffles, their spacing and surface impedance, and the location of the receiver. On the other hand daylighting performance of such covers has been studied in terms of mean illuminance level on the road platform with the following parameters: spacing/height ratio and inclination of baffles, their lighting reflectance and the road orientation. Here, and contrarily to the acoustical approach, the receiver is the driver. Simultaneous analysis of both acoustical and lighting results shows the most interesting solutions in terms of noise abatement and road illuminance level.