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Author Topic: New Construction Technology  (Read 35430 times)

kernals12

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New Construction Technology
« on: March 23, 2021, 05:23:09 PM »

Noise pollution from roads is a major issue. Excessive noise exposure is linked to a host of health problems including heart disease and stroke. It's also a big reason for opposition to new roads. If we could fix this problem, we'd make the world much better. 

Well, we can. It's called poroelastic asphalt. It substitutes polyurethane for bitumen. This makes it possible to have larger voids in the asphalt's matrix. Most road noise is caused by air getting trapped in tire grooves, compressed, and then allowed to escape, making a "pop". By adding voids, it creates a channel for the air to escape. The result is a noise reduction of 10 decibels, or about half.

The pores also allow water to drain through, eliminating the problem of runoff. But engineers haven't been able to make it durable, but as you know, I have boundless faith in technology and science, and I'm sure eventually the highway noise problem will be fixed.
« Last Edit: April 06, 2021, 11:05:46 PM by kernals12 »
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Re: Poroelastic Asphalt makes roads super quiet
« Reply #1 on: March 23, 2021, 08:38:07 PM »

On surface roads, the car engine makes more noise than the road itself, and that's up to the car manufacturers (which is easy to do but they won't because they'll lose money).
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kernals12

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Re: Poroelastic Asphalt makes roads super quiet
« Reply #2 on: March 23, 2021, 08:51:14 PM »

On surface roads, the car engine makes more noise than the road itself, and that's up to the car manufacturers (which is easy to do but they won't because they'll lose money).

Electric cars will eliminate that though. And it depends what you mean by surface roads. Above 20 mph, tire noise dominates. So parking lots and residential areas will be quieter (perhaps too quiet), but arterials will still be noisy.
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SectorZ

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Re: Poroelastic Asphalt makes roads super quiet
« Reply #3 on: March 23, 2021, 08:55:33 PM »

On surface roads, the car engine makes more noise than the road itself, and that's up to the car manufacturers (which is easy to do but they won't because they'll lose money).

You sure on that one? Years of being a pedestrian and cyclist really tell my ears otherwise. At least over 30 MPH (for the vehicles that is).
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kernals12

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Re: Poroelastic Asphalt makes roads super quiet
« Reply #4 on: March 24, 2021, 08:18:12 AM »

I'm sure that removing such a pervasive source of noise would have enormous effects on wildlife.
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kalvado

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Re: Poroelastic Asphalt makes roads super quiet
« Reply #5 on: March 24, 2021, 08:23:11 AM »

Did you ever drive on grooved pavement, with readily available air escape paths?
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zachary_amaryllis

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Re: Poroelastic Asphalt makes roads super quiet
« Reply #6 on: March 24, 2021, 09:20:53 AM »

Did you ever drive on grooved pavement, with readily available air escape paths?

i-25 near me is groved concrete, and its pretty loud even with the grooves parallel to the direction of travel.
us-287 near me is grooved perpendicularly (is that a word?) and it has a 'whine' to it, the frequency of which is proportional to your speed.
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jeffandnicole

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Re: Poroelastic Asphalt makes roads super quiet
« Reply #7 on: March 24, 2021, 09:45:53 AM »

Noise pollution from roads is a major issue. Excessive noise exposure is linked to a host of health problems including heart disease and stroke. It's also a big reason for opposition to new roads. If we could fix this problem, we'd make the world much better. 

Well, we can. It's called poroelastic asphalt. It involves adding rubber and voids to the surface. Most road noise is caused by air getting trapped in tire grooves, compressed, and then allowed to escape, making a "pop". By adding voids, it creates a channel for the air to escape. The result is a noise reduction of 10 decibels, or about half.

The pores also allow water to drain through, eliminating the problem of runoff. But engineers haven't been able to make it durable, but as you know, I have boundless faith in technology and science, and I'm sure eventually the highway noise problem will be fixed.

If 10 dBs would be a reduction of about half, then you're going from faint to faint.  Being the general threshold of a hearing problem due to noise is about 75 decibels or so, this is a non-issue, and it's likely no one is suffering a stroke or heart attack due to a 20 dB noise level.

https://boomspeaker.com/noise-level-chart-db-level-chart/
https://letstalkscience.ca/educational-resources/backgrounders/noise-on-earth-and-on-international-space-station
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Re: Poroelastic Asphalt makes roads super quiet
« Reply #8 on: March 24, 2021, 09:52:46 AM »

Noise pollution from roads is a major issue. Excessive noise exposure is linked to a host of health problems including heart disease and stroke. It's also a big reason for opposition to new roads. If we could fix this problem, we'd make the world much better. 

Well, we can. It's called poroelastic asphalt. It involves adding rubber and voids to the surface. Most road noise is caused by air getting trapped in tire grooves, compressed, and then allowed to escape, making a "pop". By adding voids, it creates a channel for the air to escape. The result is a noise reduction of 10 decibels, or about half.

The pores also allow water to drain through, eliminating the problem of runoff. But engineers haven't been able to make it durable, but as you know, I have boundless faith in technology and science, and I'm sure eventually the highway noise problem will be fixed.

If 10 dBs would be a reduction of about half, then you're going from faint to faint.  Being the general threshold of a hearing problem due to noise is about 75 decibels or so, this is a non-issue, and it's likely no one is suffering a stroke or heart attack due to a 20 dB noise level.

https://boomspeaker.com/noise-level-chart-db-level-chart/
https://letstalkscience.ca/educational-resources/backgrounders/noise-on-earth-and-on-international-space-station

Decibels are logarithmic, so a 3 dB decrease is half as loud, and a 10 dB decrease is 1/10 as loud, regardless of where on the scale you are. 0 dB is the threshold of human hearing (in the absence of other sounds), not no sound at all.

That being said, perceived volume doesn't change as much as actual volume; reducing by 10 dB will reduce what's perceived by half instead of 90%. (70 dB doesn't sound 1,000 times as loud as 40 dB to you, right?)
« Last Edit: March 24, 2021, 09:54:52 AM by 1 »
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Clinched, minus I-93 (I'm missing a few miles and my file is incorrect)

Traveled, plus US 13, 44, and 50, and several state routes

I will be in Burlington VT for the eclipse.

kernals12

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Re: Poroelastic Asphalt makes roads super quiet
« Reply #9 on: March 24, 2021, 10:14:33 AM »

And tires can also be designed to be quiet. Bridgestone's quiettrack tires incorporate diagonal grooves to the tire's edges that allow air to escape.
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jeffandnicole

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Re: Poroelastic Asphalt makes roads super quiet
« Reply #10 on: March 24, 2021, 10:31:44 AM »

And tires can also be designed to be quiet. Bridgestone's quiettrack tires incorporate diagonal grooves to the tire's edges that allow air to escape.


Tires are designed for many different types of weather and conditions.  It's up to the consumer to figure out what's best for their general driving conditions.
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1995hoo

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Re: Poroelastic Asphalt makes roads super quiet
« Reply #11 on: March 24, 2021, 12:07:54 PM »

A non-trivial consideration–and I don't pretend to know what the ideal solution for this is–involves the issue that some level of vehicle noise may be desirable on roads that have pedestrian crossings or nearby sidewalks. Blind and visually-impaired people have raised the concern that electric vehicles, as well as hybrids running in purely electric mode, can often be too quiet for people who rely on hearing to know they're coming. Obviously the idea of having those vehicles emit a beeping sound, similar to a reversing truck, is not a good solution for a variety of reasons (not the least of them being the undesirability of using a sound that might be confused with one that has a well-established meaning), but as those sorts of vehicles become more common, figuring out a solution to that issue will be important.
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kalvado

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Re: Poroelastic Asphalt makes roads super quiet
« Reply #12 on: March 24, 2021, 12:16:23 PM »

A non-trivial consideration–and I don't pretend to know what the ideal solution for this is–involves the issue that some level of vehicle noise may be desirable on roads that have pedestrian crossings or nearby sidewalks. Blind and visually-impaired people have raised the concern that electric vehicles, as well as hybrids running in purely electric mode, can often be too quiet for people who rely on hearing to know they're coming. Obviously the idea of having those vehicles emit a beeping sound, similar to a reversing truck, is not a good solution for a variety of reasons (not the least of them being the undesirability of using a sound that might be confused with one that has a well-established meaning), but as those sorts of vehicles become more common, figuring out a solution to that issue will be important.
Different animal. Tire noise should be a higher speed one, not really applicable for low-speed city streets, where engine noise dominates.
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kphoger

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Re: Poroelastic Asphalt makes roads super quiet
« Reply #13 on: March 24, 2021, 12:19:54 PM »

So... your solution is to create an environment in which blind pedestrians no longer have to even know if cars are coming?  That might not work so well on a multi-lane 45mph arterial road.  Heck, let's just cross now:  all the cars will stop anyway!
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kernals12

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Re: Poroelastic Asphalt makes roads super quiet
« Reply #14 on: March 24, 2021, 12:32:31 PM »

Jay Doblin's levels of design can guide us through solving this problem

Level 1: cars emit beeps to warn visually impaired pedestrians at low speeds
Level 2: Car bumpers are designed so that low speed crashes don't cause injuries
Level 3: cars are electronically linked to crosswalks and can provide a driver warning if pedestrians are in the way and even automatically apply the brakes
Level 4: Crosswalks are replaced by bridges and tunnels
Level 5: Blindness is cured by electronic ocular implants
Level 6: Helicopters replace cars, leaving the surface free for pedestrians
Level 7: Passenger Transportation is made obsolete by telecommunication
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kphoger

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Re: Poroelastic Asphalt makes roads super quiet
« Reply #15 on: March 24, 2021, 12:34:26 PM »

Level 0:  Realize that tire noise isn't really that big a deal.
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kernals12

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Re: Poroelastic Asphalt makes roads super quiet
« Reply #16 on: March 24, 2021, 12:35:17 PM »

So... your solution is to create an environment in which blind pedestrians no longer have to even know if cars are coming?  That might not work so well on a multi-lane 45mph arterial road.  Heck, let's just cross now:  all the cars will stop anyway!

That's jaywalking and it's illegal. Someone who tried doing that would get fined
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Re: Poroelastic Asphalt makes roads super quiet
« Reply #17 on: March 24, 2021, 12:35:51 PM »

With respect to the grooving of highways, that's tining and there is so much science behind it: https://www.fhwa.dot.gov/pavement/concrete/trailer/resources/hif18038.pdf

Transverse tining on concrete pavements was used from the late 1960s onward but that has generally shifted to longitudinal tining to reduce noise.

kernals12

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Re: Poroelastic Asphalt makes roads super quiet
« Reply #18 on: March 24, 2021, 12:38:20 PM »

Level 0:  Realize that tire noise isn't really that big a deal.
Except it is a very big deal.
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Re: Poroelastic Asphalt makes roads super quiet
« Reply #19 on: March 24, 2021, 12:57:42 PM »

So... your solution is to create an environment in which blind pedestrians no longer have to even know if cars are coming?  That might not work so well on a multi-lane 45mph arterial road.  Heck, let's just cross now:  all the cars will stop anyway!

That's jaywalking and it's illegal. Someone who tried doing that would get fined

Where does that happen? Certainly not around here, it doesn't! (Indeed a new law in Virginia this year makes it a secondary offense–a cop has to stop you for some other legitimate reason before he can ticket you for jaywalking.) Plus there are "unmarked crosswalk" laws to consider in most, if not all states, though the particularities of such laws will vary. In kphoger's example, the reference to a 45-mph speed limit would mean that here in Virginia there are no unmarked crosswalks on that road because our unmarked crosswalk law applies only to roads with 35-mph speed limits or lower. (I would also wager that 95% or more of both drivers and pedestrians have no idea what an unmarked crosswalk is.)
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kphoger

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Re: Poroelastic Asphalt makes roads super quiet
« Reply #20 on: March 24, 2021, 12:58:32 PM »


So... your solution is to create an environment in which blind pedestrians no longer have to even know if cars are coming?  That might not work so well on a multi-lane 45mph arterial road.  Heck, let's just cross now:  all the cars will stop anyway!

That's jaywalking and it's illegal. Someone who tried doing that would get fined

It's not jaywalking and it's not illegal if it's done at a crosswalk.

Here is an example of an unmarked crosswalk extending across a four-lane 45mph arterial road in suburban Chicago.  As long as a pedestrian does not "suddenly leave a curb or other place of safety and walk or run into the path of a moving vehicle which is so close as to constitute an immediate hazard [625 ILCS 5/11-1002(b)]", then it is perfectly legal to cross the street here with no requirement to yield to cross traffic.

Quote from: Illinois Vehicle Code – 625 ILCS 5/1-113
Sec. 1-113. Crosswalk.

  (a) That part of a roadway at an intersection included within the connections of the lateral lines of the sidewalks on opposite sides of the highway measured from the curbs or, in the absence of curbs, from the edges of the traversable roadway, and in the absence of a sidewalk on one side of the highway, that part of the highway included within the extension of the lateral line of the existing sidewalk to the side of the highway without the sidewalk, with such extension forming a right angle to the centerline of the highway;

  (b) Any portion of a roadway at an intersection or elsewhere distinctly indicated for pedestrian crossing by lines or other markings on the surface placed in accordance with the provisions in the Manual adopted by the Department of Transportation as authorized in Section 11-301.

Quote from: Illinois Vehicle Code – 625 ILCS 5/11-1002
Sec. 11-1002. Pedestrians' right-of-way at crosswalks.

  (a) When traffic control signals are not in place or not in operation the driver of a vehicle shall stop and yield the right-of-way to a pedestrian crossing the roadway within a crosswalk when the pedestrian is upon the half of the roadway upon which the vehicle is traveling, or when the pedestrian is approaching so closely from the opposite half of the roadway as to be in danger.

If I were a blind pedestrian crossing the road here, I'd certainly want to be able to hear traffic and not simply assume that any cross traffic will automatically stop for me as I walk across 100 feet of pavement.

Besides which, a ticket can only be issued if there's a cop there to issue one.




Level 0:  Realize that tire noise isn't really that big a deal.

Except it is a very big deal.

Except it isn't.
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Re: Poroelastic Asphalt makes roads super quiet
« Reply #21 on: March 24, 2021, 01:14:00 PM »

Here is an example of an unmarked crosswalk extending across a four-lane 45mph arterial road in suburban Chicago.

I wouldn't call that an unmarked crosswalk. I'd just call it an intersection with no sidewalks, and therefore, no crosswalks.
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kphoger

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Re: Poroelastic Asphalt makes roads super quiet
« Reply #22 on: March 24, 2021, 01:29:17 PM »


Here is an example of an unmarked crosswalk extending across a four-lane 45mph arterial road in suburban Chicago.

I wouldn't call that an unmarked crosswalk. I'd just call it an intersection with no sidewalks, and therefore, no crosswalks.

OK, perhaps that was a poor example.

Here's one with unmarked crosswalks extending between sidewalks at a 50mph Butterfield Road.  And here's where the Illinois Prairie Path crosses the road at an unmarked crosswalk nearby.
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Re: Poroelastic Asphalt makes roads super quiet
« Reply #23 on: March 24, 2021, 01:40:11 PM »

Combined with electric motors, rubber tires are already a deadly combination.  One of my colleagues was working on a rubber-tired AGT system in Florida and the [dispatcher] mistakenly released a driverless test train into his workzone.  Needless to say, he didn't hear it coming but fortunately was able to jump to safety in the nick of time (we say it the same way in Appalachia, but where I grew up it's still spelt "knick"). Low-noise pavement would be even worse.  Passenger compartments can be constructed to be virtually free from penetration of outside noises (discussed in some other recent threads, with arguments against that as well).

Personally, I don't have a strong position on these types of issues.  System Safety practices in my world require that all of these types of safety issues be identified and mitigated before we can accept a safety certification report.  Usually, the cost of the improvement versus the cost of the safety mitigation solves the safety issue (in some cases, time is the driving cost factor). 

All that being said, there is one environment that I've worked in where poroelastic asphalt and slotted tires might come in handy.  Many hospital complexes are forced to build upwards instead of outwards, as the maximum trip time between medically-dependent facilities becomes too great for a typical large, sprawling campus.  A small number of hospitals have turned to air-levitated systems with no wheels to solve the noise concerns.  This would permit other rubber tire AGT technologies to compete, perhaps opening up another niche market.  [Air-levitated AGT systems would likely see an economic benefit from additional competition, but my world is very hard to predict].
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kernals12

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Re: Poroelastic Asphalt makes roads super quiet
« Reply #24 on: March 24, 2021, 01:49:16 PM »

They're installing electronic alert systems at train crossings to replace noisy train horns. Why couldn't a similar idea work for crosswalks?
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