permaculture

[Dennis Argall <dennisargall@bigpond.com>]

I wanted to endorse what Shawn said [below]. In comparison of energy 
use, there is a big distinction between something so long lasting as 
concrete and something like flying in a plane.

There is though, the problem in human settlement in Australia, perhaps 
elsewhere, that so much urban land which could have organic life is 
being covered with concrete, with consequences for heat build up, use 
of air conditioning, rapid run-off, etc --- so, there is, as usual, a 
big question of quality of use.

Much as with aluminum, such a wonderfully long lasting material 
requiring huge inputs of electricity, so often used wastefully.

cheers

Dennis


On 07/12/2004, at 2:24 PM, McFarlandAIA@aol.com wrote:

> Concrete,
>
> Concrete is a generally a wonderful product. It is fluid and flexible 
> when
> poured and solid when it has cured. The materials that comprise 
> concrete are
> sand, water, rock and cement. The first three materials can be mined 
> locally,
> thus reducing transportation costs. Chemical admixture must be kept to 
> a minimum.
> The use of Portand Cement can be eliminated by substituting fly ash, a
> byproduct of coal burning power plants (as long as it has no 
> radioactive content).
> Here in Texas, there is a local source for fly ash. Thus, concrete, 
> used in
> this manner, can have a low environmental impact and is a very durable 
> and
> long-lasting material.
>
> Shawn McFarland, AIA, LEED AP
> Permaculture Guild of Houston