Components, systems and materials › Road furniture and safety › Noise barrier
Noise barrier
What it is
A noise barrier is a solid wall, panel system or earth bund beside a road or railway that blocks the direct sound path to nearby homes, schools and hospitals.
Where it is used
Urban expressways, elevated roads and flyovers, metro viaducts and railway lines passing close to housing and sensitive buildings.
How it works
Sound travelling from traffic to a receiver must bend over the top or around the ends of the barrier. This longer path and the acoustic shadow behind the barrier reduce the sound level. Absorptive faces soak up sound that would otherwise reflect back across the road towards buildings on the other side.
Types
- Reflective concrete or masonry walls
- absorptive panels of perforated metal with mineral wool
- transparent acrylic or polycarbonate panels
- earth bunds and vegetated barriers
- barriers on viaduct parapets
Materials
Precast concrete, aluminium or steel cassettes with absorbent cores, acrylic or polycarbonate sheets, timber, steel posts and foundations.
Height, length and position come from noise modelling of traffic and receivers. The barrier must be continuous without gaps and extend beyond the protected buildings. Posts and foundations are designed for wind load, and on viaducts for the extra load on the deck. Fire, maintenance access, light, views and bird strike on transparent panels are considered.
Installation and QA steps
- Measure existing noise levels.
- Model and design the barrier.
- Build foundations and erect posts.
- Install panels with sealed joints and no gaps at ground level.
- Measure noise after completion and maintain panels.
- Gaps at ends, joints or ground level that leak sound
- barriers too short or too low
- panel damage, graffiti and loose fixings
- loss of daylight and views from poorly chosen panels
Codes cited
- DIN 4109 (Germany): Sound insulation in buildings.
Cited by number only. We do not reproduce code text, tables or figures.
Related
Generic description for education. We do not name, endorse or compare manufacturers or products.
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