The military has a knack for making manuals for everything that has anything to do with military operations, and with so many track vehicles in the military, I would be willing to bet they have some pretty good reference materials. Check in the Dennis Reimer Digital Library, and you may find what you are looking for.
It seems to me that there was a train of thought about using 'no slump' concrete for loading areas for the military. It was about 18" thick. I went to class about 10 years ago on this. Find the concrete paving ass;n web site. they really like it when someone wants to use concrete for surfaces. It is put down with a modified asphalt machine and rolled just like asphalt. But it's not a high speed surface.
m8589...
Tracked vehicles present more of a surface abrasion problem than a loading problem. Designing a concrete pavement for the loads is easy...designing it to resist the pounding it will get from tracked vehicles is another problem.
The concrete should be relatively high strength for durability. The aggregate should be hard and durable, and as large as you can practicably use in the section you design. This is to cut down shrinkage.
If you are designing a staging area or such (like the pavement for a heavy equipment dealer or shop), then you should "armor" the joints. This is done by using steel angle with welded studs on both sides of the joints. This prevents the tracks from eroding and spalling the joints.
In short, I would use a 5000 to 6000 psi concrete mix, 1" to 1-1/2" nominal size granite or other hard coarse aggregate, a water-cement ratio of less than 0.5, and good control on placement and finishing. Design the thickness for the loads intended and pay attention to edge conditions as the control for thickness.
When you consider that tracked vehicles distribute the vehicular load over a wide area then the load transmitted to the subgrade will be low. Wheeled vehcles produce large loads over very small contact areas where the tyre touches the road surface. Consequently, the flexure in the slab and loads on the subgrade increase dramatically by comparison.
Follow Ron's mix design advice. Go for strong aggregates and don't worry too much about the polished stone value too much if you don't have high speed tyred vehicles on your road whic need to stop in a hurry.
m8589,
Hi. Are you sure this is really a requirement? Tracked vehicles were specifically designed to run on soft, muddy and/or marshy terrain and now you want to design a surface where these vehicles are not meant to run. I have heard where it is unavoidable to run the tracked veicles on finished surface, they put rubber track on top of steel track before they start.
The best would be to keep the surface unfinished and not to put any pavement over there.
I am still verifying requrements. I was told that pavement should be designed for 60-90 kips vehicles. It is unclear how many per day and what is the design time expectancy.
I do not see how any concrete surface will survive under steel track for a long time. I am thinking about 12" thick 700 psi flexural strength concrete( f'c=5000psi) reinforced with steel fiber. Is there any recomendations of using steel fibers in rigid pavement?
m8589...your design sounds good. Yes, the steel fiber will certainly enhance this application. Check with several of the steel fiber suppliers before you decide on one. My preference is the short, ductile fibers (Mitchell Fibercon or similar), mainly because I have more experience with those.
Again, pay close attention to aggregate size, type, and water-cement ratio.
The military uses rubber pads that bolt individually into each segment of track. A lot of labor but the vehicle can still be used off road with the rubber pads attached. I don't think any pavement will withstand the cutting action of a tank tread. I have seen lots of damage from just one tank getting on an asphalt road.
If you have enough of the slab and it's thick enough, I've used 3" aggregate in the mix and a superplasticizer to get the slump down... careful for segregation...
