The Home Machinist!

I like the idea of the concrete ties, and I think even for my RR in 12" gage it's possible this could be my solution where my line will cross the driveway and have to endure the weight of my 1-ton crew cab and cargo trailer passing back and forth over it.
As far as vibration, they make a form vibrator that consists of a big rubber cup with a rotating out of balance weight that can be used in an air impact or drill motor, but at last look they were all sold out. I prefer these to the "snake" type that you stick into the actual concrete especially for smaller concrete items.
FYI, concrete DISSOLVES aluminum in direct contact with it rather quickly. Most work we do with aluminum mounted to concrete requires plastic isolation plates or a protective coating. Not a problem with steel rail.

What!!!! ? A plastic pipe for a railroad tie?

At Mid-South we've used some 4" and 6" PVC pipe in places where we needed a small drain from one side of the track to the other. Would screw this directly to the track, using 2 or 3 of them in a 2' to 3' length of track. This was done to keep water from ponding on one side of the track, not to replace other types of ties.

I would be interested in seeing how a 2" plastic PVC pipe held up in service. I would think that it could/would become filled with rock and dirt and would then be very heavy.

I ran my idea by the 1" track maintenance chairman at my club and it turned into a very comprehensive discussion regarding track construction. He convinced me that my tie panel idea would result in kinks rather than a smooth transition at grade and direction changes. He liked the idea of concrete as tie material and recommended that I make individual ties rather than panels, he gave me permission to install my ties on a siding to see how they'd hold up. So when I got home Saturday I began making a 4 tie steel form for individual ties. The ties are trapezoidal in cross section, 1-1/2" on top and 2" on bottom, 9" long; I will get 28 ties out of an 80 lb bag of concrete mix, I placed an 8" length of 9 ga. tie wire for longitudinal crack control and bow ties of 16 ga. tie wire around the two inserts to prevent them from blowing out when the screw is installed. It takes me about 1/2 hour to set up, mix, place and cleanup, and I can stip the form within 24 hours and let the green ties cure in the basement. This will give me something to do after supper rather than swear at the TV.

Rkcarguy, you are absolutely correct about the reaction between concrete and aluminum, my club can be a pretty soggy place at times which would exacerbate the reaction, I'm going to isolate the aluminum rails from the concrete ties with neoprene pads. I'm anxious to see how this turns out.

Those look good!

Yes, these look very nice. I also would be very interested in how these size ties hold up.

What grade of cement did you use? Wondering if long fiber or hi strength concrete would reduce cracking, or improve surablitymwithmthmsmaller cross section?

Glenn

I was anxious to see how the ties I made would work, so I installed the first 8 ties that had 7 day cure time today. I was making batches of 4 ties a day last week, 11 pounds of Sakrete concrete mix and 16 oz of water gave me decent concrete that poured well with no honeycomb, just a few little air bubbles on the surface. An issue I found was that the inserts would fill with cement paste and had to be cleaned out, because if you didn't clean them out, the the tie would explode when the screw was installed. Hence, I have 27 ties, not 28. An old 1/8" drill bit did the trick for cleaning out the inserts; I also used 3/4" long screws rather than the 1" screws that came with the inserts so as not to over expand them and crack the ties. Expanding concrete anchors have an edge distance requirement and I had nowhere near the required edge distance. Obviously there is no latitude when placing the fasteners, they go were the inserts are. The two outside inserts were well placed and the screw heads caught the rail flange just right, the two inside screw inserts could have been better placed since the screw heads barely caught the flange, regardless the rails were well secured to the ties and the gauge was good. I also put a strip 1/16" thick neoprene under the rail to isolate the the aluminum rail from the concrete tie. I'll put the remaining ties in next week and see how they perform, time will tell.
Glenn, I used Sakrete 4000 psi concrete mix, I think fiber reinforcing would be an asset, but making small hand mixed batches with fiber reinforcing wouldn't be practical.

Interesting. I just did a search to attempt to determine concrete strength. Indications are that seven days yields approximately 70% strength, with 28 days considered to be a full cure.

H

jscarmozza wrote: ↑Fri May 07, 2021 2:59 pm ... An issue I found was that the inserts would fill with Obviously there is no latitude when placing the fasteners, they go were the inserts are.

JS,

The MLS concrete crew position the fastener locations with 4 nails or spikes of some kind, mounted through the bottom of each mold, and silver soldered in place. Then they mount a fastener onto each spike, which holds it in position and keeps it clean of cement. Wondering if the reinforcing wire you tie around the spikes causes the inner fasteners to pull away from the gauge position a little bit?

No Glenn, I just got the pin location wrong; I made my form just as you described. The reinforcing wire is bent into a figure eight and slips over the inserts after I have about a half inch of concrete in the form, it actually helps keep the inserts straight.

Several scales have been mentioned, but these plastic tie plates might be an option for rail with 7/8" or 15/16" base. They would protect the aluminum from corrosion, probably help guide the screws, and the price isn't bad.

https://allenmodels.com/backyard-railro ... -ties.html

Thank you, I didn't know plastic tie plates existed. I may try tie style 2.0 with tie plates...maybe.

I finally installed the balance of my experimental concrete ties today. I guess I didn't clean out two mollies good enough and put hairline cracks in two ties, I left them in to see how the cracks will be affected by the freeze thaw over the winter. I was talking with one of the other members, who helped me with the installation, about how to get some gauge flexibility out of the concrete ties. The inserts are fixed and there is no way to change the gauge slightly as may be desirable through curves. I had made tabbed tie plates to secure the track on my backyard test track and thought that similar plates would work with the concrete ties and give some flexibility provided I use a slotted screw hole. Any thoughts on this idea?