Slab-On-Grade For Cat D10
Slab-On-Grade For Cat D10
(OP)
I am looking at designing a slab-on-grade crossing for a Cat D10. My calculations are showing a 30" Thick Pad with #8 Rebar Min 12" Top & Bottom. The Client would like to place old railroad rails upside down approx 24" apart for the equipment to go across so the top of the concrete does not get damaged from the tracks. Is there any information helping with the calculations when placing the railway beam in the top of the slab?





RE: Slab-On-Grade For Cat D10
Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask
RE: Slab-On-Grade For Cat D10
More importantly, armor the joints and provide good load transfer. Thickness should be about 10 inches, tops. Reinforcing is probably not necessary at long as you have to control joints spaced properly.
I designed a pavement section for a CAT dealer about 30 years ago. Designed for D8's. Thickness was 8 inches, all joints were armored with 3"x3"x3/8" angle. Performed for over 25 years until they demolished the facility and built a new one. They used my design in the new one as well.
RE: Slab-On-Grade For Cat D10
Dik
RE: Slab-On-Grade For Cat D10
Dik
RE: Slab-On-Grade For Cat D10
RE: Slab-On-Grade For Cat D10
But once you have these track sections there the appearance isn't going to be so good anyway, and a trip hazard. So I would have thought better to use the steel fibres and to accept some damage from the grouser plates.
RE: Slab-On-Grade For Cat D10
Dik
RE: Slab-On-Grade For Cat D10
There are issues with the rails coming out of the concrete overtime. They have an exisiting crossing where one of the rails did come loose and was removed.
RE: Slab-On-Grade For Cat D10
The rails are problematic for several reasons. First, they will increase the potential for cracking in the concrete. Further, there is no guarantee that the tracks will alway ride on the rails, so the potential for spalling and rail pull out from tracks getting caught in the spalled edges is high.
I have had very good results with steel fiber enhanced slabs (don't waste your time with polypropylene or glass fibers).
RE: Slab-On-Grade For Cat D10
So in this case 20mm plates say 200mm wide with fixing tangs at the back could be cast-in flush. The advantage is that the plates will have no effect on the slab rebar design or position.
Then fix "something" to the plates to give the clearance (Dik suggests 1/4" proud). The "something" could be a 50mm wide plate tacked in place or a good quality plywood clamped down (this would be replaceable).
RE: Slab-On-Grade For Cat D10
Dik
RE: Slab-On-Grade For Cat D10
The spacings could be altered from rail to rail to avoid interference.
Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask
RE: Slab-On-Grade For Cat D10
RE: Slab-On-Grade For Cat D10
Your point about high local stresses from the 'sharp' parts of the track as well as the difference in hardness of the two materials (steel and concrete) is well taken.
Dik
RE: Slab-On-Grade For Cat D10