02-28-2011, 09:31 AM
I am familiar with fiber additives. They do have a function and purpose but the tensile properties come no where near steel. Getting that proposed system calc'd by an engineer and approved by the building department could be a real challenge.
The live load demonstration in the film is a very weak and unscientific demonstration. I think that they have an interesting little system which would be an improvement in many third world countries.... but there is no mention of shear testing... this guy is taking about third world countries where there are no standards to be met... and he is likely right that what he has is better than what gets done in Sudan, Haiti, etc. His demonstration has no penetrations of the shell except for a doorway. Start adding windows for light and air and everything changes. Start changing the diameter and span and everything changes.
I understand the attributes of the domes. Good attributes. I was a shop foreman for a dome manufacturer licensed by Bucky Fuller in the '70s. I know of a number of experimentals done similar to the video forty years ago.
I'm not enthused about lowering our standards down to third world metrics.
I'm not trying to be argumentative but the most dangerous structures on the planet, especially in earthquake zones, are unreinforced masonry. Basalt fiber appears to be a semi reinforced design.
It may be that there is a fiber that mixed in the right calculated mixture could produce a load bearing dome structure that would be safe in some conditions. But guessing doesn't get you there. I do know that research is ongoing for steel fiber mixes and those results are mixed.. Most non steel fiber mixes are used to minimize cracking, not provide tensile, and are in fact used in addition to steel reinforcement.
Concrete is great stuff. My own home is reinforced concrete. Concrete has been around since Roman times and it a very well documented science. There's often proposals on how to save a nickel and if saving a nickel is more important than structural safety than all I can say is I am very glad our society requires building permits.
I don't really see the advantage to eliminating steel. Grade 40 rebar is really cheap. It is also generally 100% recycled material. So I am I guess merely cautioning about cutting corners in the name of expediency.
Best wishes.
The live load demonstration in the film is a very weak and unscientific demonstration. I think that they have an interesting little system which would be an improvement in many third world countries.... but there is no mention of shear testing... this guy is taking about third world countries where there are no standards to be met... and he is likely right that what he has is better than what gets done in Sudan, Haiti, etc. His demonstration has no penetrations of the shell except for a doorway. Start adding windows for light and air and everything changes. Start changing the diameter and span and everything changes.
I understand the attributes of the domes. Good attributes. I was a shop foreman for a dome manufacturer licensed by Bucky Fuller in the '70s. I know of a number of experimentals done similar to the video forty years ago.
I'm not enthused about lowering our standards down to third world metrics.
I'm not trying to be argumentative but the most dangerous structures on the planet, especially in earthquake zones, are unreinforced masonry. Basalt fiber appears to be a semi reinforced design.
It may be that there is a fiber that mixed in the right calculated mixture could produce a load bearing dome structure that would be safe in some conditions. But guessing doesn't get you there. I do know that research is ongoing for steel fiber mixes and those results are mixed.. Most non steel fiber mixes are used to minimize cracking, not provide tensile, and are in fact used in addition to steel reinforcement.
Concrete is great stuff. My own home is reinforced concrete. Concrete has been around since Roman times and it a very well documented science. There's often proposals on how to save a nickel and if saving a nickel is more important than structural safety than all I can say is I am very glad our society requires building permits.
I don't really see the advantage to eliminating steel. Grade 40 rebar is really cheap. It is also generally 100% recycled material. So I am I guess merely cautioning about cutting corners in the name of expediency.
Best wishes.
Assume the best and ask questions.
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