[Greenbuilding] R-value of crushed stone under slab

[Alan Abrams]

excellent deduction--Thanks!


Alan Abrams

*certified professional building designer, AIBDcertified passive house
consultant, PHIUS*
*certified passive house builder, PHIUS*
cell     202-437-8583
alan at abramsdesignbuild.com
HELICON WORKS *Achitecture and Education*
<http://www.heliconworks.com/index2.html>

On Mon, Dec 7, 2015 at 11:05 AM, Norbert Senf <norbert.senf at gmail.com>
wrote:

> Google says specific heat of concrete is approx 0.8 kJ/kg-K
> 1 MJ = 1000 kJ
> Density of concrete = 2300 kg/m3
>
> This gives you a specific heat of 0.8 x 1000/2300 = 0.35 MJ/m3-K
>
> A normal concrete mix = 1:2:3 cement:sand:gravel.
> The sand fills the voids in the gravel. Therefore, for concrete with 40%
> voids (ie., for gravel), the specific heat would be .14 MJ/m3-K
>
> Norbert
>
> On Mon, Dec 7, 2015 at 10:06 AM, Alan Abrams <alan at abramsdesignbuild.com>
> wrote:
>
>> a recent project required a lot of fill under an insulated slab. washed
>> crushed bluestone (aka #57's) was used for the fill, at an average depth of
>> 24"
>>
>> any advice on how to calculate the following:
>>
>> R-value of the crushed stone
>> Heat capacity "  "  " , expressed as MJ(m^3K)
>>
>> ?????
>>
>> aa
>>
>>
>> Alan Abrams
>>
>> *certified professional building designer, AIBDcertified passive house
>> consultant, PHIUS*
>> *certified passive house builder, PHIUS*
>> cell     202-437-8583
>> alan at abramsdesignbuild.com
>> HELICON WORKS *Achitecture and Education*
>> <http://www.heliconworks.com/index2.html>
>>
>> _______________________________________________
>> Greenbuilding mailing list
>> to Send a Message to the list, use the email address
>> Greenbuilding at bioenergylists.org
>>
>> to UNSUBSCRIBE or Change your List Settings use the web page
>>
>> http://lists.bioenergylists.org/mailman/listinfo/greenbuilding_lists.bioenergylists.org
>>
>
>
>
> --
> Norbert Senf
> Masonry Stove Builders
> 25 Brouse Road, RR 5
> Shawville Québec J0X 2Y0
> 819.647.5092
> www.heatkit.com
>
> _______________________________________________
> Greenbuilding mailing list
> to Send a Message to the list, use the email address
> Greenbuilding at bioenergylists.org
>
> to UNSUBSCRIBE or Change your List Settings use the web page
>
> http://lists.bioenergylists.org/mailman/listinfo/greenbuilding_lists.bioenergylists.org
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.bioenergylists.org/pipermail/greenbuilding_lists.bioenergylists.org/attachments/20151207/1173ef67/attachment.html>