Posted on 11/23/2012 1:13:18 PM PST by 2ndDivisionVet
Some architects believe that in order to build the sustainable cities of the future, we need to look back to the log cabin era and build “skyscrapers” out of wood.
Just over a century ago, the architects and engineers who invented the skyscraper set us on the path to becoming an urban world. Tall buildings of concrete and steel helped make urban density—and the increased sustainability that comes with it—possible.
But the buildings themselves come at a heavy, and often hidden, environmental price. Concrete and steel are some of the most energy-intensive materials on the planet. The manufacture and transport of concrete, for example, is responsible for about five percent of global CO2 emissions, more than the entire airline industry.
Woodscrapers: Building Sustainable Skyscrapers
“When we talk about sustainability of buildings, we’re really tinkering around with the little minutiae”—a green roof here, a solar panel there, says Michael Green, an architect in Vancouver, Canada. “Those things are good, but they’re not even close to good enough.”
Green thinks that in order to build the sustainable cities of the future, we need to look back to the log cabin era. That is, we should be building skyscrapers out of wood. His design concept for a “woodscraper” is based on mass timber, a class of wood products that come in panels up to 64 feet long and eight feet wide. These materials, with names such as cross-laminated timber, laminated strand lumber, and laminated veneer lumber, look similar to plywood but are thicker and much stronger...
(Excerpt) Read more at utne.com ...
I would ONLY trust this if we get the wood from China.
Since we can no longer use their premium sheetrock./sarcX10
Facts or not, these are just code words for opposition to Obama's agenda. In other words, racism.
Actually, the first metal frame (iron, IIRC) had a bad problem with quickly collapsing in fires that would not have brought down a timber frame building for a while. The very thick timber beams, girders and columns would char on the outside, but it took some time for the interior wood to burn & loose strength.
However, the iron would crack from thermal stresses or the steel would warp fairly soon. In many cases, current buildings are required by code to have insulation over the metal frame members. What sort of insulation?
Sprayed on wood fiber pulp and clay mix is one method.
It can be done, after all redwoods are 200-300 feet tall. However, it would be better to take the cellulose out of wood, which is the biopolymer which makes wood strong, and put it into a substance more durable, like a plastic, and make a building out of that.
Maybe this jerk ought to check out the Great Fire of London, and many similar occurrences.
There are reasons why cities are built of brick, stone, or concrete.
All those people that perished after that wood skyscraper burned as hot as a rocket when the chiminey effect superheated the fire? We call them bumps in the road.
Seems I recall something about absence of asbestos in the WTC towers.
As far as construction materials and fire safety, though, the combination of concrete and steel was marketed as being almost fireproof and they were by comparison to wood framed structures butted side by side.
Homes and food for termites.
Besides that high rises are type I buildings and have to be built from incombustible materials and the structure fireproofed to 2, 3, and 4 hour protection!!
It also means HOLD ON TO YOUR WALLET because this building concept is not economically viable, it is will need your money to be built.
To the enviro marxist it looks like a 30 story building. To Al Queda it looks like a 30 story funeral pyre full of non believers that need to be burned.
Next up in the queue for sustainable building materials:
Legos!
Like your last sentence.
And they won’t even need a hijacked plane to take it
down.
And rots.
That’s not an actual wooden skyscraper. I was just imagining a Jenga type building made of wood and found that picture on google search.
Actually, it may not be that far-fetched within limitations.
You’re ‘way ahead of your time. Your steps certainly are sustainable.
We’re watching movies from our collection this evening. There will be no movie reviews because they’re all 5 stars, or we wouldn’t have bought them, LOL!
http://www.softwood.org/cms/data/img/uploads/files/AITC_Superior_Fire_UK.pdf (see pages 3 & 4)
When exposed to fire wood retains its strength for a
longer period of time than metal. Unprotected metals
quickly lose their strength and collapse suddenly,
often with little warning. In contrast, wood loses
strength slowly and only as material is lost through
surface charring.
Average building fire temperatures range from
approximately 700º to 900º Celsius. Steel weakens
dramatically as its temperature climbs above 230ºC,
retaining only 10% of its strength at about 750ºC.
As a rule, wood will not ignite until it reaches a temperature
of around 250ºC. Once it catches fire, wood typically
develops char at the rate of 0.64mm per minute
under severe fire conditions. The char naturally insulates
the wood and raises the temperature level it can
withstand. Thus, in a 30-minute fire, only 19mm of
each exposed surface of the glulam is lost to charring,
leaving most of the original cross section intact.
http://facweb.northseattle.edu/ssimmons/Winter/2012/TDR%20134/PPTs/Chapter4.ppt.pptx (see slide 4)
“Large wood members have greater resistance to fire than unprotected steel.
Steel, due to its high thermal conductivity, quickly heats up and loses strength during fires.
Large timbers are slow to absorb heat, slow to catch fire, and slow to burn.
The charred outer layer of a partially-burned timber insulates and protects the inner undamaged portion of the timber which retains the capacity to carry some load.”
Interesting. Often things are not as they appear at first blush. Engineered wood is very strong (and completely repeatable...each beam is just as strong as the one next to it) and it can be made as thick as desired. It can also be treated with poisons to make it taste crappy for termites. For those that have an attached garage, go take a look at your door from the house. If it’s to current code, there’s a good chance it’s wood, as wood is also an excellent fireblock.
Having said all that, wood should still be left to compete in the free market...it already has a place in fairly large structures and it should have to show its worth. The idea that we can save the world by building with wood, rather than steel, is just stupid - if for no other reason than that we’ve already (stupidly) built just about every structure we need for the next 20 years anyway, thanks to the housing and related bubbles.
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