How to reduce noise from highway rumble strips in motel 3

[suzedude]

We are building a motel near a hwy with rumble strips. Building will be 150' from road with C-store in front. Goal is to insert dead air space between outside surface and inside room, to reduce the "drumhead" effect of a solid wall.
Thanks

 

[MikeHalloran]

It should be particularly effective if the 'skin' on the highway side of the air gap is one of those thick, tall concrete walls that are starting to line urban and suburban interstates.



Mike Halloran
NOT speaking for
DeAngelo Marine Exhaust Inc.
Ft. Lauderdale, FL, USA

 

[xydrex]

By drumhead effect, I assume you mean the sound waves exciting structural vibration of the walls/panels? If this is the case you can line the walls with damping materials. These absorb and dissipate this energy by converting it to heat via the mechanism of micro-shear deformations of viscoelastic regions. This serves to increase the damp loss factor and attenuate the response. The most effective materials for this are self-adhesive rubberized asphalt, Styrene-Butadiene-Rubber and mastic (melt sheets) which are all acoustically dead because of their dense mass and low stiffness. They are commonly used in cars, but I'm sure there's building applications as well.
The concern I would have with an air gap is that there could be acoustic cavity resonances that may excited and increase the noise. The concrete wall suggested by Mike is good as a barrier to reflect approaching noise. If all else fails, look up 'decoupled noise barriers' which both block/reflect incoming noise energy and dampen any structural response to the energy that may have gotten through.

 

[suzedude]

Thanks for both posts to my question on noise dampening. Would the rubberized sheets be the same as for rubber roofing?

 

[okdb]

Hello,

I've to admit that I don't really understand your description of the situation.

Anyway, if you're worried about fasade sound insulation windows will always be the weakest point. Second, damping materials are, so to speak, not used in building acoustics. Bricks, concrete, gipsum, glass wool and steel / wood studs is what is used... and with success. Things like damping meterials have a bad effectiveness / cost ratio compared to, for example, gipsum board. Not to mention that they're good fuel in case of fire.

If the noise levels is very high, one rather use heavy fasade construction with bricks. Another solution is to add gipsum boards and increase the wall thickness. Air space in the wall should be at least 150mm, preferably 200mm, and always filled with glass wool.

Hpe this will help,

OkdB

 

[Rob45]

Your best bet would be to structurally isolate the walls from the foundation. Much of the noise will be of such low frequency that barriers will be fairly useless.

Make especially sure that the inner walls and the outer wall don't both hang from the same structural members.