Infill for transitioning track between different levels

JimmyB

JimmyB

Now retired - trains and fishing
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Hopefully the title has got your attention, here is the problem:

In my new expansion I have track coming in at different levels one raising and one dropping to meet at the same height. Having got my base (slabs) at the correct height for the lower level, the higher level has a gap between the track and base until the transition is complete. What can I use under the track, I would have thought concrete is out as the thickness (or thinness) would make it prone to cracking, so I have thought about self-levelling compound, would this hold without cracking, to is there smoother way.

The area in question is circled:

IMG_2194.jpg
 
If you could arrange the track to just traverse the last slab, you could do what a ground-worker would do, and cut that slab on the diagonal bottom-right to top-left, as we look at it.
That half-slab could then be relaid with the fall of the track.

A second thought is to bed it on ballast (possibly use SBR) and accept it will need occasional maintenance.

It depends a little on what you want to do around the formation in that area?

PhilP
 
PhilP said:
If you could arrange the track to just traverse the last slab, you could do what a ground-worker would do, and cut that slab on the diagonal bottom-right to top-left, as we look at it.
That half-slab could then be relaid with the fall of the track.

A second thought is to bed it on ballast (possibly use SBR) and accept it will need occasional maintenance.

It depends a little on what you want to do around the formation in that area?

PhilP
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The second idea is my sort of last resort, I have hoping somebody could provide a more permeant solution. Thick slabs, and I don't fancy cutting it but would work!
 
Not quite sure why you reject concrete? But what may work better for you could be postcrete, a bit of loose shuttering held in place with bricks, joined in place also with screws to some sacrificial cross battens that are sized to make your grade correct. Pour in postcrete and level it into to track with a brush. Remove track and brush now carefully to give top surface the gently water with a watering can that has small holes. Or as a first pass use an old kitchen spray bottle would disturb things less. Once the initial surface has hardened off say 20 minutes more water should seap in to harden the complete thing. Track can then be laid, there will be some sacrificial wood left once you have removed the battens, this will rot away or if it offends you prior to making up cover in cling film then when all dry wood can be removed and gaps filled with more postcrete. This will be a quick solution, overnight drying mire than ample.
 
JimmyB said:
The second idea is my sort of last resort, I have hoping somebody could provide a more permeant solution. Thick slabs, and I don't fancy cutting it but would work!
Click to expand...
Do you have a small angle grinder (100mm dia) ? if so, buy a diamond blade from evilbay - goes through slabs like a hot knife through butter :cool::cool:
 
JimmyB said:
Yes mine is a small, 125mm I think, but these drive quality 50mm thick slabs take a lot of cutting, and I am not convinced this is the best way forward.
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I've had surprising results with the diamond blade (bought them as a pair but still dirt cheap) >:)
 
Looking at the picture you could possibly make a retaining wall on both sides and fill in between with ballast so you do you have to cut the slabs.
I would second cutting grooves in the slabs either side of the track with a diamond blade and using a cold chisel to remove some concrete between then.
A diamond blade in a 4" grinder works well I've just used one to cut blacks of concrete of a post I had in the ground by cutting grooves in it and using a cold chisel and a brick bolster to crack it.
You can also get a diamond blade grinding wheel, we use one to remove lumps on the concrete sleepers at the 1:1 railway.
 
JimmyB said:
Jon, been thinking about this, not being a builder, I thought that concrete this thin would have cracked easily, but you seem to suggest there is not a problem with it.
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Postcrete is a much stronger material, i had an area near my house where when I rebuilt a loop to bricks and slabs had an area where there was a big gap in track level (poorly worked gradients by yours truly) so I adopted what I suggested, been in place for probably 5 years or more now no issues. You can see some odd surface breakup but the underlying is good and strong.
image.jpg
 
Postcrete isn't an intrinsically stronger material, but it has some additives in it that could tend to push it that way.

It is rapid hardening, and it has an anti-shrink additive. It is also usually based on 10mm aggregate rather than 20mm.

Probably what makes it more durable is the anti-shrink, combined with the smaller sized aggregate, which means that to a certain extent it self-compacts, thus removing any voids which could, in later years, be exploited by frost.
 
Rhinochugger said:
Postcrete isn't an intrinsically stronger material, but it has some additives in it that could tend to push it that way.

It is rapid hardening, and it has an anti-shrink additive. It is also usually based on 10mm aggregate rather than 20mm.

Probably what makes it more durable is the anti-shrink, combined with the smaller sized aggregate, which means that to a certain extent it self-compacts, thus removing any voids which could, in later years, be exploited by frost.
Click to expand...
Another thing is the difference in sizes of the aggregate used, a recent bag had mostly 5mm aggregate with nothing like 20mm stuff, if only it was all like that one bag! At least I was part right ‘push it that way’!
 
Hi Jim. Sorry, coming a bit late to this party.

I see you've been asking about approaches to ballasting as well. My approach to raising track (sometimes to change levels and sometimes to iron out dips where the underlying trackbed has "settled") is to pack pieces of roofing felt, slate and/or tile between the rail and trackbed and then give a generous covering of ballast.

See - Progress Report 90

Rik
 
ge_rik said:
Hi Jim. Sorry, coming a bit late to this party.

I see you've been asking about approaches to ballasting as well. My approach to raising track (sometimes to change levels and sometimes to iron out dips where the underlying trackbed has "settled") is to pack pieces of roofing felt, slate and/or tile between the rail and trackbed and then give a generous covering of ballast.

See - Progress Report 90

Rik
Click to expand...
I have done similar in packing, but have not previously "fixed" ballast in place leaving it floating.
 
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