Cement ties
Moderator: Harold_V
- Bill Shields
- Posts: 10605
- Joined: Fri Dec 21, 2007 4:57 am
- Location: 39.367, -75.765
- Contact:
Re: Cement ties
Perhaps some cheap plastic plugs to cover / fill the jollies during pouring?..or fill them with heavy grease to keep the mix out?
The fact that by definition the mollies expand and put the concrete in tension is going to cause cracks in that area no matter what -> unless you prestress the concrete from the get go
Maybe just cast a plastic pvc thru sleeve in the area where you want the bolts and put a thru bolt in from the underside of the tie.
A little slop will allow you to adjust gauge and not become a concrete stresser.
The fact that by definition the mollies expand and put the concrete in tension is going to cause cracks in that area no matter what -> unless you prestress the concrete from the get go
Maybe just cast a plastic pvc thru sleeve in the area where you want the bolts and put a thru bolt in from the underside of the tie.
A little slop will allow you to adjust gauge and not become a concrete stresser.
Too many things going on to bother listing them.
- Dick_Morris
- Posts: 2854
- Joined: Sat Jan 04, 2003 2:09 pm
- Location: Anchorage, AK
Re: Cement ties
My experience with the plastic plugs is that there is some expansion, but if there is space much of the movement is flow rather than expansion. Most of the ones I've used, but not all, are quite soft. If there is a plug of concrete in them all bets are off.The fact that by definition the mollies expand
Re: Cement ties
Dick, I think you are spot on. I suspect that the mollies expand to fill voids, then being "softer" than the concrete, must then flow. Looking at the pics, our ties are at least twice as wide, (thick), so more able to resist cracking/splitting, and there is not much opportunity for solids to infiltratre the threadways of the screws. We have hundreds in the ground now, with many having gone thru the seasonal expansion and contraction. I don't know of any cracking after installation (but then again, I am not on the crews that install these). Being in Arizona, I worry more about UV & heat degradation with the mollies and tie plates. If UV causes failures it may be in large sections all at once!!! Yikes! Then there is potential rail (metal) degradation from restrained expansion and contraction (fatique cracking). I just don't have the institutional experience nor metalurgy knowledge to hazard an intelligent guess. I personally would liked to have installed these in limited quantities and observed over more time... but the termites are winning the battle so something had to be done.
BTW, we are also testing Plastic ties cut from recycled, bulk, extruded, 12'- 2"X 4" stock. These look to be promising with $ only $ one $ major $ drawback $. Right now there are only a few sections made from these and an increasing number of switches made wholly from them. TIME WILL TELL. There is enough of both in the ground, along with some commercially made plactic ties that it may pay for others to visit us at MLS and check them out for some first hand knowledge. Looks like the world affairs may allow us to host a fall meet in October.
BTW, we are also testing Plastic ties cut from recycled, bulk, extruded, 12'- 2"X 4" stock. These look to be promising with $ only $ one $ major $ drawback $. Right now there are only a few sections made from these and an increasing number of switches made wholly from them. TIME WILL TELL. There is enough of both in the ground, along with some commercially made plactic ties that it may pay for others to visit us at MLS and check them out for some first hand knowledge. Looks like the world affairs may allow us to host a fall meet in October.
-
- Posts: 707
- Joined: Thu Nov 18, 2010 5:08 pm
Re: Cement ties
john, I saw one of your concrete sections by the ballast pile yesterday. pretty neat stuff.
-
- Posts: 605
- Joined: Mon Mar 03, 2014 5:09 pm
Re: Cement ties
Thanks Danny, after reviewing the panel idea with Rick we rejected it and decided to go with individual ties. There are 24 in place out by the 1-1/2" car barn, check them out and let me know what you think. John
-
- Posts: 707
- Joined: Thu Nov 18, 2010 5:08 pm
Re: Cement ties
jscarmozza wrote: ↑Fri May 28, 2021 3:13 pm Thanks Danny, after reviewing the panel idea with Rick we rejected it and decided to go with individual ties. There are 24 in place out by the 1-1/2" car barn, check them out and let me know what you think. John
I was looking around the yard/servicing area cuz that's where I thought you took the photos you posted. so it's by the 1.5 carbarn, ok. i'll take a look next weekend.
-
- Posts: 707
- Joined: Thu Nov 18, 2010 5:08 pm
Re: Cement ties
john I know it's late, but I was at the club today and I was checkin out the passing siding you did with concrete ties. really nice work!!
-
- Posts: 605
- Joined: Mon Mar 03, 2014 5:09 pm
Re: Cement ties
Beings you're the expert in tie replacement, thank you Danny. Since it's an experiment, I'm going to try a few different track attachment alternatives. Keep an eye on my progress and let me know what you think of the various methods. John
-
- Posts: 707
- Joined: Thu Nov 18, 2010 5:08 pm
Re: Cement ties
will dojscarmozza wrote: ↑Tue Jun 08, 2021 1:41 pm Beings you're the expert in tie replacement, thank you Danny. Since it's an experiment, I'm going to try a few different track attachment alternatives. Keep an eye on my progress and let me know what you think of the various methods. John
- makinsmoke
- Posts: 2265
- Joined: Thu Jul 10, 2003 12:56 pm
- Location: Texas Hill Country
Re: Cement ties
We tried concrete ties with the plastic screw anchors. It was work figuring out how to line them up so the rail was in gauge.
The plastic you use for tie material should be UV resistant.
Using commercial plastic ties the time factor in assembly is sometimes overlooked. It’s amazing how fast you can put track together if you never pick up a gauge.
The plastic you use for tie material should be UV resistant.
Using commercial plastic ties the time factor in assembly is sometimes overlooked. It’s amazing how fast you can put track together if you never pick up a gauge.
-
- Posts: 605
- Joined: Mon Mar 03, 2014 5:09 pm
Re: Cement ties
I would most definitely use plastic ties if they were available in 4-3/4" gauge, hopefully by the time this experiment has run its course 1" scale plastic ties will be available. That being said, a few 1" guys at NJLS got interested in my experiment and offered help and a few new ideas. What we're going to try next are lead inserts that will be cast into the concrete ties. The attached photo shows some inserts with one attached to a piece of track. The rationale behind this approach is that we can get some guage flexibility if needed because we'd be drilling the screw holes rather than relying on the location of imbedded mollies. I'm going to modify my forms and cast about 2 dozen ties and see how this idea works.
- Bill Shields
- Posts: 10605
- Joined: Fri Dec 21, 2007 4:57 am
- Location: 39.367, -75.765
- Contact:
Re: Cement ties
HECK...why not just LEAD ties?
Nice and heavy (won't float away) and reasonably UV resistant.
Nice and heavy (won't float away) and reasonably UV resistant.
Too many things going on to bother listing them.