We all know that concrete pavement is costly relatively to that constructed with bitumen. But sky high price increment of bitumen, raised question to highway engineers whether it is relevant to use such pavement considering its longevity and frequent maintenance requirements. Then concrete pavement is tested and initial costs of both materials are compared. Now these are almost same. Regarding longevity a bitumen surface may serve only 7-10 years whereas a concrete surface can serve successfully for 15-40 years.
With the longevity a slight modification in wearing course can render a concrete pavement of lower noise pollution. Yes we are talking about exposed aggregate concrete surfacing. We have learned about it in our previous few posts. We are providing here a link in regards to it.
Expose aggregate concrete surfacing is compressed to EACS in this post for convenience of writing this post. EACS has successfully applied in several UK roads and served as good for last 15-20 years. We are providing a list:
2. A50 in the Derbyshire
3. M23 near the Gatwick
4. A13 in the Essex
5. A449 in the Wales
We have already learned about how aggregate are exposed in EACS. Its exposed aggregate surface provides a random contact points with tyre treads and reduce noise pollution. It can reduce noise up to 3 dBA. Can you realize 3DBA noise reduction? It is almost equivalent to a 50% reduction in traffic flow. With noise reduction of this level it provides excellent skid resistance to the surface and requires low long term maintenance.
We will discuss about another method of noise reduction and providing skid resistance known as concrete grinding and grooving un the next post. This reduces noise more efficient than EACS.