# Concrete Roadbed Help



## jbwilcox (Jan 2, 2008)

This has probably been asked before, but here goes:

In late May I am going to start redoing my roadbed and I thought I would use concrete.

Can anyone give me some advice?

How wide should it be? Just as wide as the track or should it be wider?

I am thinking of making it 4 inches deep -- is that sufficient?

How do you attach the track to the road bed after it is dry? Can you wait until the concrete is semi dry and then press the track down into it, or is there a better way of doing it?

What about ballasting it? I use Bridge Tailings which I get from Manufacturer's Minerals outside of Seattle in 50 pound bags. It is the best looking ballast I have ever found.

Finally, any Pros or Cons to cement roadbed?

Thanks,

John


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## iaviksfan (Dec 27, 2007)

John, i asked this very same question last month. Most people will tell you not to do it, but depends on your circumstances. My post was Track Fail under track and roadbed. If you search in here for concrete roadbed, there is an excellent pdf that Marty made about his method. 
Happy Rails, 
Greg R.


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## jbwilcox (Jan 2, 2008)

I guess I do not know how to use the search function because I can find nothing regarding concrete roadbed from Marty.

John


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## NTCGRR (Jan 2, 2008)

John the more you do it the easier it gets.
Some folks tell me it takes 4 hours there first 20', later it takes 4 hours to do 50' or more.
3/8" rebar in the middle is the biggest key, don't over think it, just lift it alittle as you pour. Bailing wire ties the ends together. and at switches.
2 bags of concrete mix and 1 bag of motar mix makes it stickyer to work with. Kinda like cake batter when ready to pour.
The 3 bags will get you about 15ft of 4" X 2" 
If your on solid ground 2" is fine, if your on 2ft of fill make it 3" or so.
Just scrap the grass off, don't dig down in, you want water to run off it like a mini sidewalk.
use screws for your form stacks, besure its level side to side.
and the key word is feather it in.(thats not the right word???)


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## John J (Dec 29, 2007)

Mine is about 2 inches to 2.5 deep. 

It is just a little bit wider than the ties 3.75 inches.

For switches I make it as wide as the widest part of the switch......7 inches

Don't forget level side to side. 


I have lost interest in my RR for over a year and a half..... All I have done is clear off the vegetation and crap that blew into and onto the layout 

Fix a few joints and that was it. I was able to run trains. ( Battery Power ) 

With concrete road bed I have not had to touch a thing. 

JJ


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## Totalwrecker (Feb 26, 2009)

Concrete tip; Primary concern; be sure to encase all metal in the concrete. Prop your rebar up on rocks, don't drive rebar into the ground and then wire to that. Metal expands as it rusts and if you create a path for moisture, you may suffer failures. Thinner pours are more susceptable, so be sure the ends of your wire ties are tucked in. 

I think Marty's correct word is Tamp it in, you want it to liquify slightly and tamping or vibration will do that if moist enough. Liquifying gets all the powder wet and helps it settle for a stronger pour. 

JJ goes back after it hardens and drills and sets in plastic anchors. Then he uses bailing wire to loop around the screw and over a tie. This allows the tie and track to move, but not blow away. 

John


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## NTCGRR (Jan 2, 2008)

I guess I was assuming adding water to the mix in a wheel barrel. LOL, I have never used dry mix by itself, John thanks for clearing that up.


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## Totalwrecker (Feb 26, 2009)

Excuse me Marty, my advice was in addition to yours. I meant a wet mix too. An impatient mixer can leave dry clumps, tamping can help disolve those. That's all. 

John


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## jbwilcox (Jan 2, 2008)

Thanks for the replies.

When I get back from Kayenta I am going to start with cement on one section of my railroad.

I will let you know how it comes out.

No one mentioned bout pressing the track into the semi dry cement to "lock" it in place.

Any comments on that?

John


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## NTCGRR (Jan 2, 2008)

Let concrete dry, track is another story.


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## Pete Thornton (Jan 2, 2008)

John, 
how to use the search function 
Simple answer - don't bother, use Google. Try googling "site:mylargescale.com concrete roadbed" (without the quotes. The 'site:' makes google just search the one website. 
The PDF comes up second http://1stclass.mylargescale.com/stevec/MLS-Topic-Article/ConcreteRoadbed.pdf 

pressing the track into the semi dry cement to "lock" it in place 
Expansion/contraction will pop it out - let it float on the flat surface.


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## FlagstaffLGB (Jul 15, 2012)

John, enjoy your trip to Kayenta....maybe Seattle will dry out a bit by the time you return. 

I know that area of the northwest is often wet and snowy, but you might also want to check your local building department for expected frost depth. Most of the information provided is very good for building the concrete bed (reinforcement, leveling, not pressing the ties into the wet cement and anchors), but you need to know that all concrete, including reinforced concrete will eventually crack. So if you are constructing a long level "concrete" beam in your back yard and it is only 2-4" inches thick, it needs some ground support to help with heaving and ground movement. I've done some of this in the past and found that using a post hole digger (borrow one or buy them from Home Depot at about $20), and dig holes beneath the area of your concrete "beam" about every five or six feet apart. Good to go to average frost depth....Seattle, you are probably at 12-18"...but check you location. I would then put one vertical piece of 3/8" rebar into the hole and fill it with concrete. Think of it as bridge supports for your concrete beams. 

The other issue is going to be expansion and contraction...but this is for the concrete, not your track. Concrete sidewalks and driveways normally have control joints every 16-20 feet. You can use premold (again, bought cheaply at the Home Depot or Lowes) and it normally is 1/2" x 3-1/2" x 8' long...costs about $2-4 a piece. You can place it in flush and it won't be noticed in your railbed mold. 

Lastly, whatever you use for ballast can be put over your rails once the concrete is dry and the track laid and secured. Should work fine and yes you may have some maintenance if it gets shifted around during the course of a normal year and weather. Also, depending upon your backyard and surface drainage (take pictures or mark it during a great downpour), I think I would add some natural run-off culverts under the road bed (2-3" ABS works well) and you can later model those into real culverts. Should be fun. 

You'll have to take some pictures of your progress and post them so we can all continue to comment. 

Ed


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## Dwight Ennis (Jan 2, 2008)

Posted By jbwilcox on 20 Apr 2013 04:52 PM 
I guess I do not know how to use the search function because I can find nothing regarding concrete roadbed from Marty.

John

Here you go John...

*Marty's Concrete Roadbed PDF *


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## CliffyJ (Apr 29, 2009)

John,

Just to chime in, I'm very happy with my concrete roadbed decision. After 2 years (for the oldest sections), not one crack has showed up. I'm using Marty's formula, with a 4"wide x 3-4" deep profile, 3-4" of gravel beneath, and 1 centered rebar (3/8") down the middle.

Finally got back to some track laying yesterday, here's a recent pic:










Long way to go, and I'm not exactly the quickest modeler on this forum...

I'm using John's plastic anchor + screw + wire clip method; quick, cheap, easy. I just swapped out my baling wire though for copper (peeled out of some scrap romex), because the steel wire seemed to be corroding too rapidly. The copper should oxidize nicely (and I couldn't find cheap stainless wire), and it seems stiff enough. HOWEVER, it does not spring back, it just bends. So maybe it was a dumb switch, we'll see.

You'll want a hammer drill for the anchor holes. 

The reason for this method is to allow the track to float when the rails expand and contract. I don't think you'll want to set the track in damp concrete, because it won't have anywhere to go... the rails might bust off of the ties (though someone with more experience will have a better opinion on that). 

You'll find several approaches to forming, mine was sort of weird because of all the tight curves. No matter what method you use, I'd suggest that just before you lay gravel and pour, you set in plenty of drain and plastic conduit pieces under the form. I went overkill: about 8' between drains (corrugated 4", maybe 24" long) and 4' between "conduit" (actually, hard plastic irrigation line) pieces. Then I took a **** of a lot of pics, because they might get buried (sure enough, I cant see any of them now!). Just insurance for the future though. And even if I don't use them, I'm finding that I may have created a neat mega-habitrail for the critters...









===>Cliff


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## John J (Dec 29, 2007)

Holy Moely There Cliff. You really got into the concrete road bed.


Looks great 

JJ


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## iaviksfan (Dec 27, 2007)

This is a question for those who have already poured. After pouring one section, do you add any kind of key or notch, So the next section interlocks with it? Or do you use expansion joint material between the sections? 
Thanks 
Greg R.


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## Totalwrecker (Feb 26, 2009)

You probably have rebar sticking out, to hold it together. Unless you've kicked a lot of dirt against the face,







it should stick fine. Always pre wet the old so it doesn't suck moisture out of the new mix. Old cured concrete just needs to be wetted. 
A CreteCraftsman once told me it's very important to have all metal totally encased by the concrete. Rebar and wire ties were always propped up on rocks. Any exposed metal was asking for trouble. Metal expands as it rusts, well the rust does. Climate cycles, hot and cold will draw any water in along the metal and eventually (several years) your roadbed is likely to crack. That it hasn't happen to others is no guarantee, but I only offer it as shared knowledge. 

So in light of the above, pour directly onto the previous pour. 

Just had a funny thought imagine a pumper crew tackling the big pour! The hose man would need to be mighty nimble! 

Have Fun 

John


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## Nutz-n-Bolts (Aug 12, 2010)

Cliffy, Wow, you have sure been busy since I last saw your pike here on MLS. It's really taking shape. Tons of potential there!










Greg R., It's just as John said. Leave some rebar sticking out where you stop the pour. Wire tie your next stick to it, wet the old crete and keep pouring.



John, Most of us could only be so lucky to have a railroad big enough to require a mixer and pump tuck to fill our forms! And yes, you would have to be awful quick with the hose!


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## iaviksfan (Dec 27, 2007)

Thanks guys, always have an answer for me..... 
Greg R.


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## John J (Dec 29, 2007)

Posted By iaviksfan on 29 May 2013 11:54 AM 
This is a question for those who have already poured. After pouring one section, do you add any kind of key or notch, So the next section interlocks with it? Or do you use expansion joint material between the sections? 
Thanks 
Greg R. If it is the last pour of the day I leave a piece of rebar sticking out and slope the end like a wedge. . I leave it rough. Then The next time I am going to pour there to continue on I add the rebar for the next sections and wire it to the piece sticking out. 

I wet the slope just before I pour the next section. Then continue 

JJ


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