New Construction Technology

[formulanone]

Purdue University researchers have developed the world's whitest paint, with an albedo of .981. They say it could eliminate the need for air conditioning (and drive up the neat for heating). This would greatly reduce the amount of softening of asphalt that leads to rutting.

The polar opposite of Vantablack.

[kernals12]

Purdue University researchers have developed the world's whitest paint, with an albedo of .981. They say it could eliminate the need for air conditioning (and drive up the neat for heating). This would greatly reduce the amount of softening of asphalt that leads to rutting.

The polar opposite of Vantablack.

They should spray that stuff on Alaska's highways

[kernals12]

Researchers at Worcester Polytechnic in Massachusetts have found that by adding an enzyme found in human blood they can make concrete that will heal any cracks automatically within 24 hours. The enzyme reacts with carbon dioxide in the air to form calcium carbonate.

They say that this would increase the cost of concrete by a small amount while quadrupling its durability. This is a big deal for highway and bridge engineering. And it's a reminder that plenty of innovation in Massachusetts can come from outside 495.

The guy who discovered it, Nima Rahbar, told me in an email that he founded a company, Enzymatic, to commercialize it.

We really need self healing, ultra high performance fiber reinforced concrete.

Imagine if you could build bridges without any rebar that would last for centuries.

[SkyPesos]

Is there a word for "gadgetbahn" , except it's for roads? I think that word would apply to most things in this thread.

[kernals12]

Is there a word for "gadgetbahn" , except it's for roads? I think that word would apply to most things in this thread.

And just like the streetcar fanatics who coined that phrase, you are making the questionable assumption that today's solutions are satisfying.

[kernals12]

A startup called Petra has come out of stealth mode with a new tunnel boring technology that melts instead of drills through rock. They are targeting underground utility lines in the short term but if it works there, it's inevitable it'll be used for larger earth moving jobs.

[Rothman]

A startup called Petra has come out of stealth mode with a new tunnel boring technology that melts instead of drills through rock. They are targeting underground utility lines in the short term but if it works there, it's inevitable it'll be used for larger earth moving jobs.

Seems like a disaster waiting to happen if they hit an unknown gas line.

[kernals12]

A startup called Petra has come out of stealth mode with a new tunnel boring technology that melts instead of drills through rock. They are targeting underground utility lines in the short term but if it works there, it's inevitable it'll be used for larger earth moving jobs.

Seems like a disaster waiting to happen if they hit an unknown gas line.

Wouldn't that be a problem with conventional drilling methods?

[Scott5114]

It would be a problem, sure, but a conventional drill wouldn't be running into the flammable gas with a temperature high enough to melt rock.

[GaryV]

technology that melts instead of drills through rock.

So where does this lava end up?  The melted rock is going to cool and solidify sometime.  It doesn't just go away.

[kalvado]

technology that melts instead of drills through rock.

So where does this lava end up?  The melted rock is going to cool and solidify sometime.  It doesn't just go away.

I suspect it is about shock cooling to form stressed glass which breaks into small pieces.

[Dirt Roads]

technology that melts instead of drills through rock.

So where does this lava end up?  The melted rock is going to cool and solidify sometime.  It doesn't just go away.

I suspect it is about shock cooling to form stressed glass which breaks into small pieces.

Every construction project is *supposed* to calculate and develop detailed management plans for cut/fill/borrow and muck.  I've worked on some projects that were brilliantly managed, others that didn't pay attention to the plan, and a few that seemed *very* confused about the whole concept.  Yes, the lava would be considered to be "muck".  By the way, there are entire industries that revolve around management of molten slag from a wide variety of sources, so this shouldn't be a problem (but would definitely cost more to transport and dispose).  Like everything else, I would consider this a complex math problem.

[kernals12]

The Michigan DOT put out an interesting press release about their use of carbon fiber reinforced bridges. They're building 2 of them as part of the reconstruction of Interstate 94 in Detroit.

The big benefit is that, unlike steel, carbon fiber doesn't rust, so no more concrete cancer.

[formulanone]

The Michigan DOT put out an interesting press release about their use of carbon fiber reinforced bridges. They're building 2 of them as part of the reconstruction of Interstate 94 in Detroit.

The big benefit is that, unlike steel, carbon fiber doesn't rust, so no more concrete cancer.

The carbon fiber replaces the steel inside the bridge. I've wondered why it hasn't been used before, frankly...the reduced mass would also facilitate the process (requiring a reduced physical effort, uses more efficient equipment).

Only drawback is that I've heard — somewhat dubiously — that carbon fiber does tend to break down slightly over time, depending on impacts and the bonding of the composites in use. Perhaps insulating it with concrete would slow down that process, but it probably has to be a carefully-chosen material mix which will not corrode the composite matrix.

[kernals12]

The Michigan DOT put out an interesting press release about their use of carbon fiber reinforced bridges. They're building 2 of them as part of the reconstruction of Interstate 94 in Detroit.

The big benefit is that, unlike steel, carbon fiber doesn't rust, so no more concrete cancer.

The carbon fiber replaces the steel inside the bridge. I've wondered why it hasn't been used before, frankly...the reduced mass would also facilitate the process (requiring a reduced physical effort, uses more efficient equipment).

Only drawback is that I've heard — somewhat dubiously — that carbon fiber does tend to break down slightly over time, depending on impacts and the bonding of the composites in use. Perhaps insulating it with concrete would slow down that process, but it probably has to be a carefully-chosen material mix which will not corrode the composite matrix.

The problem is carbon fiber is terrifically expensive.

[kkt]

The Michigan DOT put out an interesting press release about their use of carbon fiber reinforced bridges. They're building 2 of them as part of the reconstruction of Interstate 94 in Detroit.

The big benefit is that, unlike steel, carbon fiber doesn't rust, so no more concrete cancer.

The carbon fiber replaces the steel inside the bridge. I've wondered why it hasn't been used before, frankly...the reduced mass would also facilitate the process (requiring a reduced physical effort, uses more efficient equipment).

Only drawback is that I've heard — somewhat dubiously — that carbon fiber does tend to break down slightly over time, depending on impacts and the bonding of the composites in use. Perhaps insulating it with concrete would slow down that process, but it probably has to be a carefully-chosen material mix which will not corrode the composite matrix.

The problem is carbon fiber is terrifically expensive.

So is having major spans closed for years just 36 years after their completion.

https://www.seattle.gov/transportation/projects-and-programs/programs/bridges-stairs-and-other-structures/bridges/west-seattle-bridge-program/west-seattle-bridge-repair

[SEWIGuy]

The Michigan DOT put out an interesting press release about their use of carbon fiber reinforced bridges. They're building 2 of them as part of the reconstruction of Interstate 94 in Detroit.

The big benefit is that, unlike steel, carbon fiber doesn't rust, so no more concrete cancer.

The carbon fiber replaces the steel inside the bridge. I've wondered why it hasn't been used before, frankly...the reduced mass would also facilitate the process (requiring a reduced physical effort, uses more efficient equipment).

Only drawback is that I've heard — somewhat dubiously — that carbon fiber does tend to break down slightly over time, depending on impacts and the bonding of the composites in use. Perhaps insulating it with concrete would slow down that process, but it probably has to be a carefully-chosen material mix which will not corrode the composite matrix.

The problem is carbon fiber is terrifically expensive.

So is having major spans closed for years just 36 years after their completion.

https://www.seattle.gov/transportation/projects-and-programs/programs/bridges-stairs-and-other-structures/bridges/west-seattle-bridge-program/west-seattle-bridge-repair

So which is more expensive?  Also please include the time value of money in your calculations.

[kernals12]

https://www.agg-net.com/news/tarmac-in-basalt-fibre-low-carbon-concrete-trial

In Britain, they are using concrete reinforced with basalt fiber instead of steel for improvements to the M42 at Junction 6. Basalt fiber doesn't rust, which means structures built with it will last much longer.

[kernals12]

https://www.uta.edu/news/news-releases/2022/02/11/hossain-highway-pins

A professor at UT Arlington has received 2 contracts from TxDOT for a new method of slope stabilization that is 50% less expensive than conventional means

[kernals12]

Quaise Energy has received $40 million in VC funding to begin real world demonstrations of its microwave drilling technology. Their intended market is geothermal energy, but I see no reason why the same technology could not be used for highway tunnels.

[skluth]

The engineers battling to stop global warming ruining roads - BBC

Australia's floods of 2010-11 spread devastation and damage across Queensland, with 33 people losing their lives and causing billions in losses across the state. The floods also damaged 19,000km of roads, including those needed for emergency and delivery vehicles.

It was a stark lesson in the importance of weather-proofing Queensland's most vulnerable roads, to ensure that future flooding would lead to fewer people being cut off.

Since then, Queensland has been using a process called foamed bitumen stabilisation. This injects small amounts of air and cold water into hot bitumen, the sticky dark substance typically used for road surfaces.

The bitumen then expands and forms a water-resistant layer. The result is a stronger yet flexible road surface or pavement that is better able to withstand flooding.

Rest of article linked in headline

[kernals12]

Nima Rahbar, the professor at WPI who developed the concrete that heals itself with enzymes from human blood, told me that they've poured a test slab of it at an Air Force Base in Florida and in a few months they will check the results.

[Revive 755]

Wonder how well Vantablack would work on a signal backplate?

[kernals12]

Cornell University showed off 3D printing robotic arm. They say it eliminates the need for concrete molds. Combined with fiber reinforcement replacing rebar, this would utterly transform civil engineering and make all sorts of projects much less expensive.

[triplemultiplex]

I'm thinking about the end of life-cycle for concrete made with millions of tiny fibers instead of rebar; can one recycle it in the same manner we do now?  It's easy to crush the concrete away from rebar to separate the two components and the ferrous nature of the steel rebar makes it even easier to get useful aggregate from old concrete.  But if it's full of threads made of fiberglass, graphite or even graphene, what then?  Will those contaminate the aggregate with a material that detracts from its usefulness? To the point where we have to landfill older fiber concrete?

Seems like a solvable problem, I hope.

There is also a nagging concern I have about tiny fibers and the potential health and environmental hazard.  Folks who work with fiberglass need to be protected from inhaling fine particles, and we all know about asbestos.  Will these brilliant new nano-fibers end up having a similar effect when aerosolized during emplacement or removal and 'drill' into people's lung tissue and foment cancer?  I really hope not because I would hate for the engineering potential of nano-fibers to be torpedoed by this potential problem.