I've had better luck with pre-mixed grout. The Portland cement seemed to work for a while then break up with temperature changes. Perhaps you could start by spraying on a vinyl tack coat used when adding concrete over existing. It may help the binding as well as remains somewhat flexible.
Here in Hawaii the temperature doesn't change much but we get about 20 feet of rain. Nothing seems to survive that well except grass!
Neil Erickson, Umauma Plantation Railway
Also read here
http://cs.trains.com/grw/f/6/t/159524.aspx
Tom Trigg
There is this discussion going on over at My Large Scale forum -
http://forums.mylargescale.com/16-track-trestles-bridges-roadbed/32545-adding-portland-cement-ballast-material.html
Maybe it will be of help to you.
I have had mixed results. Where the drainage is fine, no issues. Where it is poor the ballast surface has cracked or splintered off. What this means to me after examining the damage is that the ballast if made a solid surface by adding concrete it must be sloped away from the center line of the track to allow run off. I live in NC and while moderate in temperature, we have our share of nights and days below 32 F. It is not so much the permeability of the stone concrete mixture as it is the issue of water not collecting underneath it becoming trapped and subject to expansion and contraction. The run off needs to be channeled away from the track for a fair distance.
Nothing is more fairly distributed than common sense: no one thinks he needs more of it than he already has.
Does anyone have any experience in adding a small amount of portland cement to your ballast material? I live near Atlanta and was worried that it may cause the track (I am using LGB) to not be able to expand as the temperature changes. Am I better off using gray fine material?
Thanks to all for your help.
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