MATERIAL SPECIFICATION FOR HIGHWAY NOISE BARRIER

摘要

Noise is one of the environmental pollutants that are encountered in daily life. Noise pollution has become a major concern of communities living in the vicinity of major highway corridors. In view of the rapid development, it is essential to study highway noise with respect to various causative factors and adequate measure should be taken to control it. In this paper an effort has been made to reduce highway noise with the construction of noise barriers. The most effective and efficient way to control highway noise is to design noise barriers. Noise barriers reduce the sound, which enters a community from a busy highway by absorbing it, transmitting it, reflecting it back across the highway, or forcing it to take a longer path. Noise barriers are normally designed to provide to the tune of 15 dBA noise reduction at the receptor. To produce an effective sound shadow, a noise barrier should be dense and close to the highway. The amount of incident sound that a barrier transmits can be described by its sound Transmission Loss (TL). As a rule of thumb, any material weighing 20Kg/m~2 or more has a transmission loss of at least 20 dBA. Such material would be adequate for a noise reduction of at least 10 dBA due to diffraction. Weight of 20Kg/m~2 can be attained by lighter and thicker or heavier and thinner materials. The greater the density of the material, the thinner the material may be. TL also depends on the stiffness of the material that has a TL of at least 25 dBA or greater is desired and would always be adequate for a noise barrier. Some of the materials which can be used for the construction of noise barriers are concrete, brick, steel, aluminum, wood, transparent panels, plastics etc. This paper highlights the various construction materials and their specifications so that adequate noise barriers can be designed to reduce highway noise.