Engineering question...

What's standard?????

My driveway is 6" thick with reinforcement mat and 4" of 3/4" crushed sub-base....

 

I'm no civil engineer but I'll try and adapt what I learned on another form of engineering to this.

well, take the maximum weight of a set of tandems to be conservative in your calculations. 34,000 pounds.

The problem lies with the concrete. Do you know if there is any reinforcement? concrete is different from pour to pour as well. If you want to be ultra conservative, look online for bearing strengths of lightweight concrete and assume no reinforcement in the slabs.

Then, use the good old formula STRESS equals FORCE divided by AREA

Take the force (34,000 pounds) and divide by the area of the contact patch of the tires. You could even divide 34,000 pounds by 8 to get 4250 pounds per tire and divide that 4250 by the contact patch of one tire.

So search online to find the average size contact patch of a typical semi tire under full load. (use the area in SQUARE INCHES).

take 4250 and divide by this area to give you pounds per square inch, or PSI. This is the stress the tires are placing on the concrete.

next, find the compressive strength. I did a quick search and looks like a lot of average concrete pours fall between 35 and 50 Mpa for strength (MegaPascals which is metric). 1 MPa = roughly 145 Psi.........so 35 Mpa is roughly 5075 PSI for compressive strength.

The stress you calculate must be under 35Mpa or 5075 psi to be safe.

Now this is really vague, but should give you somewhat of an idea what you are up against. The stress model I've given assumes the layers under the concrete prevent the slabs from "bending". If there are air pockets under the concrete, or a soft material that will squish under the weight....then the slab will come under a bending force too. The ability of the slab to resist this depends on the thickness, and the strength of the slab.

Any civil engineers on here? How close do I have this? LOL

 

Driveways are not poured to hold a truck. Most likely you have a 4" slab with WWF as reinforcement ( WWF is the steel you see that is rolled out and has 6" squares). Most of the time they do not use rebar due to cost and there's no need for it. But of course it all depends on where your house is and how they did the work.

If you can dig down on the side of the slab see how thick the concrete is. 6" just might be ok but you never know what, if any, reinforcement was used. You might look around your housing area and see if anybody pulled up their driveway. Then you could have a pretty good idea what you have.

You might get away with parking the tractor there but if you have another place that's close I'd go there first until you know for sure what you have.

 

Just a tractor probably doesn't weigh a whole lot more at the ground than a car. Remember you're spreading that weight across a larger contact area. 10 tires vs. 4.

I would regularly park my empty water truck on my standard concrete driveway. Never had a problem.

When I built my shop I poured a 6" reinforced slab. Now I can park my truck in there full at 46,500 lbs without a problem..

 

Tractor only means you are spreading approx 31k lbs over ten tires..should be good for a standard concrete driveway, but your second issue would be the first to check on..and don't forget the neighbors, tey might get quirky...or jealous!

 

That's an awful heavy tractor.. Even with the tank on mine it's only 22K empty..

 

OK, you caught me--glad it was you not the coop! I wasn't awake there..you are right, I was thinking of my MT weight with trailer...21-22k sounds a lot better. Far better on that standard driveway.

I could have said that weight includes all three of my girlfreinds....ROFL

Hope the wife or Nana don't read this thread!