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Every bamboo pole is different.. For this reason bamboo could never fit into modern engineering practices. Engineers use things like I-beams because, (in theory

Every bamboo pole is different.. For this reason bamboo could never fit into modern engineering practices. Engineers use things like I-beams because, (in theory) each one is the same and they have been tested (probably millions of times) Their structural characteristics are known. So an engineer can sign off on a building and the team can get architectural indemnity insurance. Bamboo, and also things like using the entire trunk of young trees, are much much more efficient in terms of embodied energy. Eg, a tree is designed for strength / flexibility, why cut it up and then glue it back together to form a gluelam beam? Its because engineers can sign off on it then.. Maybe theres some innovative way to integrate stuff like bamboo into modern engineering practices, maybe each individual unique bamboo pole could be scanned (like an MRI) and AI could be used to accurately structurally model it. The the whole structure could be accurately modeled and signed off on in theory.

greggyb 8y ago
Don't we deal with the variability of natural products in lots of places by grading? This example is not structural, but every piece of beef has a USDA grade. I think it is a matter of coming up with a standard (maybe it is imaging each piece of bamboo) means of categorizing the qualities of concern, and then selling in grades. Each grade would indicate a minimum quality or set of qualities.
- everyone 8y ago
  Structural engineers are weird. They want to be able to guarantee that a structure can withstand a certain load. Eg. They'll calculate the maximum load the floors will take (eg. if its an office and filled with filing cabinets) and then multiply that by a safety factor of 10 and design the structure to support that, at the very least. They'll probably make it even stronger so the structure never even flexes (which is not unsafe but it can just unsettle people) The goal is, it is impossible for this structure to fail under any likely conditions, so eg. any kind of wind load thats been experienced in so many decades.
  - DrPhish 8y ago
    We do this with dimension lumber. There are a couple of different processes of assessing the strength of a piece of lumber, but the designation is MSR (Machine Stress Rated) "is intended for any engineered application where low variability in strength and stiffness properties is primary product consideration" (1). It looks like there have been attempts to do the same thing with bamboo, starting with adapting existing lumber grading machinery (2) I don't see why it would be impossible to use bamboo in engineering applications as long as the physical properties of a given grade of bamboo stock could be guaranteed. I assume treatment for pests, rot and fungus would also need to be applied to guarantee that those properties remain inviolate, but am no expert on bamboo. (1) - https://www.wwpa.org/western-lumber/structural-lumber/machine-stress-rated-(msr) https://www.wwpa.org/western-lumber/structural-lumber/machin... (2) - https://www.researchgate.net/publication/313531323_Grading_of_Bamboo https://www.researchgate.net/publication/313531323_Grading_o...
  - greggyb 8y ago
    How is this incompatible with a product that comes with minimum guarantees? Say we have a way to grade bamboo (this is the question mark in my argument). Grade X bamboo would support the floor in question. Grade 10X bamboo would support 10x the floor in question. For the floor in question, use Grade 10x bamboo. I mean, it seems like something similar must be going on in structural lumber. Take 2x4s for example. This is one piece of wood out of a tree. There must be natural variation across the population of trees providing wood for these. How do we handle that except by saying that this piece of lumber meets minimum guarantees but may be stronger than that minimum, and is statistically likely to exceed the minimum.
learc83 8y ago
Houses in the US are usually built with wood beams that are very variable in structural characteristics. Whole bamboo is probably more variable, but this isn't an insurmountable problem.
RugnirViking 8y ago
Wooden planks actually do regularly come with knots and large differences in strength due to the grain - we are able to work around this due to familliarity with them at all parts of the supply chain. As for why we use planks and not logs? They're all the same size - A lot easier to transport and use.
- everyone 8y ago
  yeah but timbers like that are very unlikely to be used structurally anywhere outside of small domestic scale construction.
agumonkey 8y ago
I saw articles about cutting bamboo poles into blades~ (for lack of a better term) to be joined later to form regular blocks. Less simple but easier at scale.

greggyb 8y ago

Don't we deal with the variability of natural products in lots of places by grading? This example is not structural, but every piece of beef has a USDA grade. I think it is a matter of coming up with a standard (maybe it is imaging each piece of bamboo) means of categorizing the qualities of concern, and then selling in grades. Each grade would indicate a minimum quality or set of qualities.

everyone 8y ago
Structural engineers are weird. They want to be able to guarantee that a structure can withstand a certain load. Eg. They'll calculate the maximum load the floors will take (eg. if its an office and filled with filing cabinets) and then multiply that by a safety factor of 10 and design the structure to support that, at the very least. They'll probably make it even stronger so the structure never even flexes (which is not unsafe but it can just unsettle people) The goal is, it is impossible for this structure to fail under any likely conditions, so eg. any kind of wind load thats been experienced in so many decades.
- DrPhish 8y ago
  We do this with dimension lumber. There are a couple of different processes of assessing the strength of a piece of lumber, but the designation is MSR (Machine Stress Rated) "is intended for any engineered application where low variability in strength and stiffness properties is primary product consideration" (1). It looks like there have been attempts to do the same thing with bamboo, starting with adapting existing lumber grading machinery (2) I don't see why it would be impossible to use bamboo in engineering applications as long as the physical properties of a given grade of bamboo stock could be guaranteed. I assume treatment for pests, rot and fungus would also need to be applied to guarantee that those properties remain inviolate, but am no expert on bamboo. (1) - https://www.wwpa.org/western-lumber/structural-lumber/machine-stress-rated-(msr) https://www.wwpa.org/western-lumber/structural-lumber/machin... (2) - https://www.researchgate.net/publication/313531323_Grading_of_Bamboo https://www.researchgate.net/publication/313531323_Grading_o...
- greggyb 8y ago
  How is this incompatible with a product that comes with minimum guarantees? Say we have a way to grade bamboo (this is the question mark in my argument). Grade X bamboo would support the floor in question. Grade 10X bamboo would support 10x the floor in question. For the floor in question, use Grade 10x bamboo. I mean, it seems like something similar must be going on in structural lumber. Take 2x4s for example. This is one piece of wood out of a tree. There must be natural variation across the population of trees providing wood for these. How do we handle that except by saying that this piece of lumber meets minimum guarantees but may be stronger than that minimum, and is statistically likely to exceed the minimum.

learc83 8y ago

Houses in the US are usually built with wood beams that are very variable in structural characteristics. Whole bamboo is probably more variable, but this isn't an insurmountable problem.

RugnirViking 8y ago

Wooden planks actually do regularly come with knots and large differences in strength due to the grain - we are able to work around this due to familliarity with them at all parts of the supply chain. As for why we use planks and not logs? They're all the same size - A lot easier to transport and use.

everyone 8y ago
yeah but timbers like that are very unlikely to be used structurally anywhere outside of small domestic scale construction.

agumonkey 8y ago

I saw articles about cutting bamboo poles into blades~ (for lack of a better term) to be joined later to form regular blocks. Less simple but easier at scale.