# Rubber-coated ballast demonstrates improved track resilience



## on30gn15 (May 23, 2009)

So, who is going to be first to try this in G scale?
https://www.railjournal.com/in_depth/rubber-coated-ballast-demonstrates-improved-track-resilience

*Rubber-coated ballast demonstrates improved track resilience*


> With railways seeking to cut maintenance costs and preserve their assets, the search for new innovative ways to minimise the adverse effects of failures associated with ballast aggregate on heavy-haul lines has intensified.
> 
> Comsa, Spain, developed Neoballast in collaboration with Mapei, Spanish infrasturcture manager Adif, and the Polytechnic University of Catalonia in 2011 with the goal of potentially doubling the lifespan of conventional ballast and improving noise and vibration behaviour. Tests of the product are now underway as part of the European Union’s Horizon 2020 research initiative.
> 
> The Neoballast aggregate consists of conventional ballast stone coated with synthetic elastomers generated from recycled motor vehicle tyres with the aid of a binder. The new ballast is designed to reduce the rate of degradation and settlement of the ballast layer and also to reduce maintenance interventions and costs.


That "triaxial shear test" sounds interesting: what kind of measuring devices would have been used? 
I'm guessing from the words that they were measuring ballast displacement and forces on 3 axes.


> Preliminary tests to determine the mechanical performance of Neoballast were conducted by the consortium at the University of Granada, Spain, using a triaxial shear test on a track used by passenger trains. Cyclic dynamic load tests ranging from 5kN to 65kN were conducted, which is equivalent to 20-tonne axleloads at a frequency of 5Hz.


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## Dave Meashey (Jan 2, 2008)

Forrest;

While I don't like to "rain on somebody else's parade," I have learned from personal experience that the laws of physics don't always scale down very well. In the past, I used "starter" size granite chicken grit for ballast. When mixed three parts chicken grit to one part dry mortar mix, it remained fairly stable, once misted in place with a garden hose.

Coating the chicken grit with rubber would be another challenge. I suspect that even a very well thinned rubber cement would still be too "gummy." You would have to create a means for breaking the chicken grit apart once the rubber cement dried. OR I suppose one could (1) have the track laid and wired in. (2) Add and profile the ballast. (3) Then spray the thinned rubber cement over the ballasted track, AFTER applying masking tape to the rail heads. Battery and live steam folks could probably skip the masking tape and enjoy better tractive effort as a bonus.

Anyway, it would provide an interesting experiment in large scale.

Cheers,
David Meashey


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## jimtyp (Jan 2, 2008)

Seems like a good idea. Landscape companies now sell rubber mulch, although a bit big for G-scale. Maybe chop it further in a blender?


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## Greg Elmassian (Jan 3, 2008)

Well, scale size ballast would probably work if we had scale sized rain, and only scale sized animals and wind speed scaled down to 1:20 or 1:29


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## on30gn15 (May 23, 2009)

Greg Elmassian said:


> Well, scale size ballast would probably work if we had scale sized rain, and only scale sized animals and wind speed scaled down to 1:20 or 1:29


I wonder if it would also require scale gravity.


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## Chris Scott (Jan 2, 2008)

Tires are toxic. Worn out ties are toxic. Ground up tires (for children's playgrounds and used to make artificial turf and mulch, etc.) is toxic. If the ground up tires give off particles or dust, or chemicals that can be absorbed or breathed it's toxic. and you will be affected if you mess with it - and not in a good way. 

Roads made of recycled tires and rubber coated ballast will leach harmful chemicals into drain water which will permeate the ground and groundwater, and flow into rivers, lakes and the ocean contaminating them. 

Moral; you can't take something toxic and repurpose it without its original toxicity continuing with it in whatever form. Caveat: unless extreme and often very expensive measures are taken to alleviate or mitigate the toxicity. Miracles are possible but as in life extremely rare.

Just something to think about.


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## bmwr71 (Jan 30, 2010)

Chris, can you list the toxic chemicals that are coming from the tires and in what quantities and their ill effects? Would be more informative than just some general statements.

Doug


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## Dave Meashey (Jan 2, 2008)

Doug;

Just a guess, but I suspect that unless the tire rubber is subjected to intense heat, the bad stuff stays in the rubber. A few years ago I bought a ramp, called "Bridgit," to ease our autos over the combination curb/gutter in our development and onto our driveway. It is made from recycled tires, but did not come with chemical warnings. (And I have no intentions of subjecting it to a torch.)

Best,
David Meashey


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## Greg Elmassian (Jan 3, 2008)

I read up a bit, and dust from grinding/sanding the stuff seems to be universally bad.


But, looking at dangerous stuff leaching from the rubber seems to be some brands/processes, while others don't have an issue.


I've read some reports that allude to what Chris says, and others that do not find issues.


So universal damnation does not seem proper at this point, but if you were to sprinkle it on your corn flake would require further investigation.


Greg


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## Chris Scott (Jan 2, 2008)

bmwr71 said:


> Chris, can you list the toxic chemicals that are coming from the tires and in what quantities and their ill effects? Would be more informative than just some general statements.
> 
> Doug


Styrene-butadiene or styrene-butadiene rubber (SBR) describe families of synthetic rubbers derived from styrene and butadiene

It is also known as styrene-butadiene rubber (SBR). The chemical styrene is toxic to the lungs, liver, and brain. Synthetic additives are added to achieve stabilization. Often however, synthetic latex can be made of combinations of polyurethane and natural latex, or a combination of 70% natural latex and 30% SBR










That's 5 min via Google; "chemical composition of tires"
Hope that helps with your future curiosity and internet searches


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## placitassteam (Jan 2, 2008)

I would think that the fine particles that you leave behind as you drive down the road would be a lot more of a problem than chunks of the stuff just lying there.


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## Chris Scott (Jan 2, 2008)

Greg Elmassian said:


> I read up a bit, and dust from grinding/sanding the stuff seems to be universally bad.
> 
> But, looking at dangerous stuff leaching from the rubber seems to be some brands/processes, while others don't have an issue.
> 
> ...


"I've read some reports that allude to what Chris says, and others that do not find issues."

Allude? "do not find issues" ? You have got to be kidding.​
Do we really need to revisit this category of products and materials that join others that forged the territory;

Lead
Asbestos
Gasoline, Diesel, etc. (hydrocarbons as a class)
DDT
Cigarettes
Who can forget the company CEOs testifying before congress under oath "Cigarettes are not addictive.' a few years later the same CEOs were again their, under oath, and sall testified, "I believe Cigarettes are addictive."​And all the others yet to be discovered, invented and/or identified.

*Environmental concerns (perspective on section below)*
The section below while it sounds relative benign has to be viewed with considerable skepticism given the number of time in the past the same type characterization has been applied to products and/or materials that turned out to be only at the beginning. early, intereum, etc., of a comprehensive evaluation of the effects either longer term or technology to assess the material as thoroughly as required, as exemplified by lead, asbestos, etc. Our analysis is only as good as our technology, tools, methods, experience and intelligence. Who's doing the research, who are they funded by or affiliated with and what are their conclusions, unfortunately based on past experience is one of the most critical factors in evaluating any "authoritative, accurate or objective" information.
_____________________________________________________________________________
*Tire recycling*
Tire recycling, or rubber recycling, is the process of recycling waste tires that are no longer suitable for use on vehicles due to wear or irreparable damage. These tires are a challenging source of waste, due to the large volume produced, the durability of the tires, and the components in the tire that are ecologically problematic.[1]

Because tires are highly durable and non-biodegradable, they can consume valued space in landfills.[1] In 1990, it was estimated that over 1 billion scrap tires were in stockpiles in the United States. As of 2015, only 67 million tires remain in stockpiles.[2] From 1994 to 2010, the European Union increased the amount of tires recycled from 25% of annual discards to nearly 95%, with roughly half of the end-of-life tires used for energy, mostly in cement manufacturing.[3][4]

Newer technology, such as pyrolysis and devulcanization, has made tires suitable targets for recycling despite their bulk and resilience. Aside from use as fuel, the main end use for tires remains ground rubber.[2][5]

In 2017, 13% of U.S. tires removed from their primary use were sold in the used tire market. Of the tires that were scrapped, 43% were burnt as tire-derived fuel, with cement manufacturing the largest user, another 25% were used to make ground rubber, 8% were used in civil engineering projects, 17% were disposed of in landfills and 8% had other uses.[6]

*Environmental concerns*
Due to their heavy metal and other pollutant content, tires pose a risk for the leaching of toxins into the groundwater when placed in wet soils. Research has shown that very little leaching occurs when shredded tires are used as light fill material; however, limitations have been put on use of this material; each site should be individually assessed determining if this product is appropriate for given conditions.[8]

For both above and below water table applications, the preponderance of evidence shows that TDA (tire derived aggregate, or shredded tires) will not cause primary drinking water standards to be exceeded for metals. Moreover, TDA is unlikely to increase levels of metals with primary drinking water standards above naturally occurring background levels.[28]
____________________________________________________________

To MLS:
Sorry that's a little long winded and somewhat off topic but Greg's approach hit a hot button needing a bit of hard headed rebuttal.


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## Greg Elmassian (Jan 3, 2008)

Chris, the subject was are the rubber products toxic, right? (not cigarettes, CEO's etc)

so to that point, in the posting you made, here are the salient points, _copied directly from your post_:

Due to their heavy metal and other pollutant content, tires pose a *risk *for the leaching of toxins into the groundwater when placed in wet soils. Research has shown that very little leaching occurs when shredded tires are used as light fill material; however, limitations have been put on use of this material;* each site should be individually assessed* determining if this product is appropriate for given conditions.[8]

For both above and below water table applications, the preponderance of evidence shows that TDA (tire derived aggregate, or shredded tires)* will not *cause primary drinking water standards to be exceeded for metals. Moreover, TDA is unlikely to increase levels of metals with primary drinking water standards above naturally occurring background levels.

The first quotes says poses a risk, does not go further than that.

The second quote almost reverses it in saying "will not cause drinking water standards to be exceeded"

My research gave me the same kind of thing, some maybe's some yes's and some no's.

While personally I do not like the idea at all of using rubber mulch, and I am as suspicious as you (well almost ) about having this stuff around and on children's playgrounds, what you find is all over the map.


More quotes and references welcome of course. I'll never use the stuff.



Greg


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## Chris Scott (Jan 2, 2008)

Greg Elmassian said:


> Chris, the subject was are the rubber products toxic, right? (not cigarettes, CEO's etc)
> 
> so to that point, in the posting you made, here are the salient points, copied directly from your post:
> 
> ...


Greg:

The first examples (i.e., lead, etc.) were about long term harmful effects and hindsight. The quote embodied the same equivocation you first posted. In between came the warning of the jeopardy, faults and limitations inherent in any assessment (repeated below.) that precede the quoted text. The CO's? That was an example of, it it sounds too good to be true it probably is. No matter who and where it's said.

Environmental concerns (perspective on section below)
The section below while it sounds relative benign has to be viewed with considerable skepticism given the number of times in the past the same type of characterization has been applied to products and/or materials that turned out to be only at the beginning. early, intereum, etc., of a comprehensive evaluation of the effects either longer term or technology to assess the material as thoroughly as required, as exemplified by lead, asbestos, etc. Our analysis is only as good as our technology, tools, methods, experience and intelligence. Who's doing the research, who are they funded by or affiliated with and what are their conclusions. Unfortunately based on past experience is one of the most critical factors in evaluating any "authoritative, accurate or objective" information.

I hope a second reading of the above might more clearly make my point. I think I may by character and habit have more skepticism than you.

While it seems you may have missed my point or post's flow(?), I think we probably agree neither of us wants to live next to a tire disposal site. As well as have more sensitivity toward those who live next to or be exposed to any hazardous site or substance through no fault of their own. There but by the grace of God...


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## FlagstaffLGB (Jul 15, 2012)

On the other side, since asphalt is used in roadways (which I'm sure that the tar substance has plenty of bad stuff in it), they are grinded up old tires and mixing it with asphalt to make "rubberized" paving. Several web sites indicate that it takes between a couple of hundred to a thousand years for synthetic tires to "decompose". Burning is not a good idea. So, mixing it in with something that I don't see civilizations doing away with and making the ride quieter and smoother, seems like a good idea. Now, trying to model it into a G scale railbed....I'll pass.


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## Mr.American (Nov 9, 2008)

*My experience with rubber mulch*

Gents, I've been setting up a garden railroad for Halloween for about 4 or 5 years. My front garden (9x18') is just right for this. There are small flowers and dwarf Alberta Spruce. The garden has a ground cloth covered with rubber mulch from tires. 


For Halloween, I set up an oval track, put out a station and a few buildings, and light the scene with temporary lamps aimed down low. Then I deliver the candy with gondola cars. The kids love it.

One thing I don't like is the large texture (1/2" size chunks).


What I do like about the rubber mulch is:
- it doesn't rot or go away each year
- it doesn't seem to attract bugs
- it is easy to move around to level the track 
- it seems to stay in place, at least for my temporary application.


If it starts to get a little thin, I just get another bag and spread it around. It has lasted the better part of a decade in our harsh Michigan winters.
The toxicity does not seem to prevent the plants from growing.
(Maybe it even keeps the moles away.)

Bob Winkel Rochester, MI


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