[GSBN] SB & Acoustics + nominating Rick Green

[martin hammer]

If Tim is nominating Rick Green, I give an emphatic second.  (Assuming Rick
wants to be on the GSBN?)

Also, Tim, you didn¹t give Rick¹s website (and I found way too many
Benchmark Developments on google).

Martin


On 11/15/10 11:10 AM, "Tim Owen-Kennedy" <timok33 at gmail.com> wrote:

> Hi Sarah,
> 
> The Sound wall in Nevada was built by Rick Green's Benchmark Development. and
> had a concrete tilt up wall on one side.
> 
> here is his website.
> 
> Tim
> 
> p.s. if we don't already have too many rice farmers and if Rick is willing I'd
> be willing to lift my personal ban on Nominating more Californians to this
> list to Nominate him. He's a good, practicle builder with lots of perspective
> that genuinely differs from the "conventional" Straw bale builder. He grew up
> and still is a rice and wheat farmer. And does some manufacturing as well as
> construction.
> 
> On Sun, Nov 14, 2010 at 8:00 AM, martin hammer <mfhammer at pacbell.net> wrote:
>> Hello Sarah,
>> 
>> Some years ago a strawbale highway wall was constructed in the state of
>> Nevada.  I¹ve seen photographs and text written about it, but I can¹t put my
>> hands on either, even after doing a moderate internet search.  I did find
>> reference to this system of construction being used as an acoustic barrier in
>> a Nevada Department of Transportation report.  You can see it via the
>> following downloadable link:
>> 
>> http://www.nevadadot.com/reports_pubs/Research_Pubs/pdfs/ResearchReports/2001
>> /01_006A_part1C.pdf
>> 
>> On page D-2, ³Hay Bales² are described as one of many ³Previously Submitted
>> Soundwall Systems².  Further on there is a matrix evaluating the different
>> systems according to an array of criteria.
>> 
>> I¹ve often thought that strawbale walls would be great acoustic barriers on
>> the side of highways.  I don¹t know how the Nevada wall has performed and
>> weathered, but the challenges for these walls seem to be
>> 1. that the wall¹s height be adequately restrained against lateral loads from
>> wind and earthquakes
>> 2. that the bales remain dry enough to avoid deterioration
>> 
>> I have seen strawbale landscape walls by others where I know the bales rotted
>> (a 10 year old wall with lime-cement plaster) because I did conclusive
>> probing, or where I suspect the bales rotted because of a hollow sound.  I¹ve
>> thought for some time that putting a ventilating ³roof² on a plastered bale
>> landscape wall would greatly improve its longevity.  Or one can simply accept
>> that the bales are just formwork for ³structural² plaster and let them
>> deteriorate, but that wouldn¹t work so well for tall walls or acoustic
>> barriers.
>> 
>> The acoustic issues for a highway sound barrier are worth carefully
>> considering.  Some were mentioned by Derek and Graeme.  I agree with most of
>> their points.  I¹ll add a few things.
>> 
>> * Mass is an important element in acoustic barriers, but it attenuates mostly
>> the lower frequencies.  Transmission of higher frequencies can be diminished
>> by less massive materials, such as straw bales.  Here we¹re talking about
>> transmission through the barrier, not above or around it (as Derek points
>> out).  So extent of the barrier is important.  
>> 
>> * The surface of the barrier, both its texture and it absorptive/reflective
>> qualities, is important.  So on a straw bale wall, a roughly textured clay
>> plaster finish would absorb more sound, and the sound that was reflected
>> would be more dispersed, as compared with a dense, smooth, cement plaster
>> finish.
>> 
>> * There is a difference in acoustic performance between having an acoustic
>> barrier on one side of a highway versus both sides.  Having the barrier on
>> one side creates a worse situation on the side without the barrier, because
>> it imposes additional reflected sound on that side.  Having the barrier on
>> both sides creates back and forth reflectance.  That can make the sound in
>> between the walls (on the highway and its shoulders) rather unpleasant.
>>  Although I suppose we don¹t really care (or care much less) about the
>> acoustics on the highway itself.  Having an acoustic barrier on both sides,
>> with back and forth reflectance, can change the acoustic dynamics and the
>> reach of the sound on either side of the highway, because the location and
>> height of the ³source² can change as it bounces off the walls.
>> 
>> I do think a plastered strawbale wall provides a good balance of mass and
>> insulation/absorption (if that¹s an accurate way to state it) for an acoustic
>> barrier, in a similar way that a plastered strawbale wall provides a good
>> balance of mass and insulation for thermal performance.
>> 
>> Those are my thoughts on the subject.
>> 
>> Martin (bouncing off the walls) Hammer
>> 
>> 
>> 
>> On 11/11/10 6:42 PM, "Sarah Johnston" <sarahjohnston at ihug.co.nz> wrote:
>> 
>>> Hello!
>>> 
>>> We've had an inquiry from a local road works company about using straw bale
>>> as a landscape wall for acoustical reasons along the main highway (keep in
>>> mind, in this neck of the woods...the main north-south road is two lanes
>>> only...).
>>> 
>>> They have requested acoustical research and data.  We have the information
>>> in Bruce's book, but I thought I would check to see if there has been any
>>> new testing or research done recently that you could share with us?
>>> 
>>> Does anyone have experience with landscape walls along busy highways?
>>> I'm questioning the overall long-term durability of this type of landscape
>>> wall.  Your thoughts and input are all welcome.
>>> 
>>> Many thanks!
>>> 
>>> Cheers,
>>> Sarah
>>> 
>>> Sarah Johnston
>>> Sol Design, Ltd.
>>> 50A Connolly Street
>>> Geraldine New Zealand
>>> 03 693 7369
>>> sarahjohnston at ihug.co.nz
>>> 
>>> 
>>> 
>>> 
>>>  
>>> 
>>> 
>>> 
>>> _______________________________________________
>>> GSBN mailing list
>>> GSBN at greenbuilder.com
>>> http://greenbuilder.com/mailman/listinfo/GSBN
>> 
>> 
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>> 
> 
> 


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