5 ms·

Fun stuff! Master masons would 'tune' walls to specific applications (more load, better aesthetics Etc, and this can make that possible by non-masters. But mor

Fun stuff! Master masons would 'tune' walls to specific applications (more load, better aesthetics Etc, and this can make that possible by non-masters. But more interesting to me is that places that previously were too cost sensitive to afford clever masonry might benefit. The canonical example in California are acoustic "freeway walls" which are block walls that line the freeways as a mechanism for minimizing noise in the surrounding neighborhoods. The "simple" way these are build tends to just reflect the noise somewhere else, and has some really interesting effects with low clouds. If on the other hand you could mathematically design an audio 'notch' filter out of the walls using a precise set of openings that would absorb sound and dissipate its energy into the wall, you could create much more effective sound walls. And if you could do this so that anyone working on the wall has a good chance of successfully laying out the wall correctly, then you could apply it to the miles and miles of walls that Caltrans builds every year. That would be pretty neat.

jagraff 6y ago
Could you elaborate on the "interesting effects with low clouds" caused by the walls? I've never heard of that before, sounds interesting
- hobs 6y ago
  Bouncing the noises.
- ChuckMcM 6y ago
  The walls on either side of the 85 freeway (as an example) in Cupertino have occasionally set up a resonance, which when the fog as come in over the Santa Cruz mountains creates spots where you can stand and hear very odd "oooh-waaah-oooh-waaah" noises. The first time I heard it I hypothesized it was a didgeridoo being played nearby, but you could walk 100 yards in either direction and the sound would fade, only to pick up again another 100 yards or so further away.
  - saagarjha 6y ago
    Stand…on the freeway? Or on the other side of the walls?
    - ChuckMcM 6y ago
      In the neighborhood next to the freeway.
wizardforhire 6y ago
Fun facts: Helmholtz Resonators [1] are used all over industry and in aerospace to do just this. For instance the shroud around a high bypass turbo fan will have a honeycomb sandwich layer with precise holes in the middle of each cell to create an array of resonators tuned to cancel out specific frequencies. My favorite application similar but different from what you’re describing from antiquity is the acoustical effect of certain Mayan and Aztec pyramids. Here’s a video[2] [1] https://en.wikipedia.org/wiki/Helmholtz_resonance https://en.wikipedia.org/wiki/Helmholtz_resonance [2] https://youtube.com/watch?v=wsMGCF_pS-M https://youtube.com/watch?v=wsMGCF_pS-M
apprenticemason 6y ago
Most of the freeway walls you’re referring to are made using concrete forms and not block. I would feel extremely sorry for the company and the masons that would need to create block walls that are miles long, in no shade, during California’s summer. I’ve worked for a masonry company for about four years and recently started my apprenticeship to become a brick block and stone mason a year ago. Working in this sector has made me truly appreciate the amount of work (Work = force*distance) that goes into any masonry. You see brick block and stone EVERYWHERE but what you might not realize is each brick, each block, each stone, has to travel from their source to their final destination. Usually that’s done by someone like me; if we’re lucky, we’re using M2 mobile hydro units coupled with a boom lift to reach whatever heights we need to hit. If we’re not so lucky, we’re building scaffolding by hand, stocking everything by hand, mixing mortar (in a mixer) by hand and using buckets to get the mortar where it need to be. It’s truly mind boggling and back breaking work. I realize this is an emerging technology but some of the masons I work with could reproduce work very close to this, maybe not mm accuracy but close enough where you’d never see the difference. And 3 months to lay ~15,000 bricks is an INSANELY long time. To put that number into perspective, a crew of 5 guys with average skill (3 masons, a laborer, and an operator making mud), given no extra equipment besides a mixer could pound out about 1000 brick in a day. That’s including everything from setup to cleanup. Some of the guys I work with have been a mason for 40 years and they posses some incredible skill and can create amazing things and damn they’re fast too. The sad fact of the matter is most blueprints don’t want fancy masonry work anymore. It’s too cost prohibitive. We charge about $25/square foot of stone that’s without added arches or keystones or corbels etc; that also doesn’t include material costs (mortar, stone, tar paper, mesh, staples, etc). One experienced mason can throw up 100 square feet in a day, sometimes more given the differences in material. I wish we got contracts to create the beautiful buildings like in downtown Chicago or Milwaukee but it’s too much of a numbers game with real estate developers now. No one wants to pay us to create art, just slap it up and go man go! With all that being said, man I’d like to have some time to play around with this tech! Or at least get to be the guy that holds the camera all day ;) looks like a breezy job compared to what I do everyday.
- rhapsodic 6y ago
  Props to you. I used to work as a carpenter, and I see the world differently because of it. When I walk down a city sidewalk past a brick building, I can picture what it was like, in say, 1910, when the brick facade was being laid. I'll look at a brick and wonder if it was hot, or cold, or rainy or sunny when that particular brick was bumped into its final resting place by the handle of the trowel, and I'll wonder what the mason had on his mind when he laid it. When I used to build staircases, it always gave me pause to think that people not yet born would be walking up and down those stairs long after I'm dead. And that's the nature of your work. Your work product will outlive you by decades, or possibly centuries.
nullc 6y ago
Computer optimized noise barriers are a thing, https://en.wikipedia.org/wiki/Sound_baffle#Highway_noise_barriers https://en.wikipedia.org/wiki/Sound_baffle#Highway_noise_bar... Common freeway walls are cast concrete preforms, so it's easy to make them have a particular geometry. In terms of protecting the surrounding community from the noise, the wall tops actually have a lot more impact than the wall geometry itself due to edge diffraction.

jagraff 6y ago

Could you elaborate on the "interesting effects with low clouds" caused by the walls? I've never heard of that before, sounds interesting

hobs 6y ago
Bouncing the noises.
ChuckMcM 6y ago
The walls on either side of the 85 freeway (as an example) in Cupertino have occasionally set up a resonance, which when the fog as come in over the Santa Cruz mountains creates spots where you can stand and hear very odd "oooh-waaah-oooh-waaah" noises. The first time I heard it I hypothesized it was a didgeridoo being played nearby, but you could walk 100 yards in either direction and the sound would fade, only to pick up again another 100 yards or so further away.
- saagarjha 6y ago
  Stand…on the freeway? Or on the other side of the walls?
  - ChuckMcM 6y ago
    In the neighborhood next to the freeway.

wizardforhire 6y ago

Fun facts: Helmholtz Resonators [1] are used all over industry and in aerospace to do just this. For instance the shroud around a high bypass turbo fan will have a honeycomb sandwich layer with precise holes in the middle of each cell to create an array of resonators tuned to cancel out specific frequencies. My favorite application similar but different from what you’re describing from antiquity is the acoustical effect of certain Mayan and Aztec pyramids. Here’s a video[2] [1] https://en.wikipedia.org/wiki/Helmholtz_resonance https://en.wikipedia.org/wiki/Helmholtz_resonance [2] https://youtube.com/watch?v=wsMGCF_pS-M https://youtube.com/watch?v=wsMGCF_pS-M

apprenticemason 6y ago

Most of the freeway walls you’re referring to are made using concrete forms and not block. I would feel extremely sorry for the company and the masons that would need to create block walls that are miles long, in no shade, during California’s summer. I’ve worked for a masonry company for about four years and recently started my apprenticeship to become a brick block and stone mason a year ago. Working in this sector has made me truly appreciate the amount of work (Work = force*distance) that goes into any masonry. You see brick block and stone EVERYWHERE but what you might not realize is each brick, each block, each stone, has to travel from their source to their final destination. Usually that’s done by someone like me; if we’re lucky, we’re using M2 mobile hydro units coupled with a boom lift to reach whatever heights we need to hit. If we’re not so lucky, we’re building scaffolding by hand, stocking everything by hand, mixing mortar (in a mixer) by hand and using buckets to get the mortar where it need to be. It’s truly mind boggling and back breaking work. I realize this is an emerging technology but some of the masons I work with could reproduce work very close to this, maybe not mm accuracy but close enough where you’d never see the difference. And 3 months to lay ~15,000 bricks is an INSANELY long time. To put that number into perspective, a crew of 5 guys with average skill (3 masons, a laborer, and an operator making mud), given no extra equipment besides a mixer could pound out about 1000 brick in a day. That’s including everything from setup to cleanup. Some of the guys I work with have been a mason for 40 years and they posses some incredible skill and can create amazing things and damn they’re fast too. The sad fact of the matter is most blueprints don’t want fancy masonry work anymore. It’s too cost prohibitive. We charge about $25/square foot of stone that’s without added arches or keystones or corbels etc; that also doesn’t include material costs (mortar, stone, tar paper, mesh, staples, etc). One experienced mason can throw up 100 square feet in a day, sometimes more given the differences in material. I wish we got contracts to create the beautiful buildings like in downtown Chicago or Milwaukee but it’s too much of a numbers game with real estate developers now. No one wants to pay us to create art, just slap it up and go man go! With all that being said, man I’d like to have some time to play around with this tech! Or at least get to be the guy that holds the camera all day ;) looks like a breezy job compared to what I do everyday.

rhapsodic 6y ago
Props to you. I used to work as a carpenter, and I see the world differently because of it. When I walk down a city sidewalk past a brick building, I can picture what it was like, in say, 1910, when the brick facade was being laid. I'll look at a brick and wonder if it was hot, or cold, or rainy or sunny when that particular brick was bumped into its final resting place by the handle of the trowel, and I'll wonder what the mason had on his mind when he laid it. When I used to build staircases, it always gave me pause to think that people not yet born would be walking up and down those stairs long after I'm dead. And that's the nature of your work. Your work product will outlive you by decades, or possibly centuries.

nullc 6y ago

Computer optimized noise barriers are a thing, https://en.wikipedia.org/wiki/Sound_baffle#Highway_noise_barriers https://en.wikipedia.org/wiki/Sound_baffle#Highway_noise_bar... Common freeway walls are cast concrete preforms, so it's easy to make them have a particular geometry. In terms of protecting the surrounding community from the noise, the wall tops actually have a lot more impact than the wall geometry itself due to edge diffraction.