riven1950 wrote:
ivylog wrote:
Glad you know so much. Last week I had a 12 yard concrete truck put the front tires on 48 hours old concrete...it was a front loader truck. 3000 psi concrete means when fully cured it will support 3,000 lbs / square inch. In 48 hours it's 25% cured. Do the math for a tire with 120 psi in it. In 5 days it's 35-40% cured.
I started to tell the OP 2 days but said 5 in hopes someone who has never poured concrete would not spout off.
PS: TT tires have closer to 60 psi in them. In the last 60 days I have pour aprox 50 yards
Not sure what the PSI in the tire as to do with it. Are you saying a loaded Concrete truck puts the same pressure on the concrete as an unloaded one because the tire PSI is the same? So a 4000 lb TT will have same effect as a 14,000 lb 5th wheeler as long as the tire pressure is the same? I think not.
All I suggested was that the OP do a google search for concrete cure rates and recommendations for driving on it. You try that and see how many people think it is wise to do as you said.
If it is my money I would err on the side of caution. You can do as you please.
I think what he is saying is that each tire has roughly a 36 square inch contact patch so a 14K fifth wheel has approx 11 thousand pound supported by 144 sq inches if you do the math, it comes up to 76 pounds per square inch. A typical 4” slab is usually 3-3500 pounds per square inch weight limit. A 14k fifth wheel won’t even make it breathe hard.
My fifth wheel sits on a 4” slab with expansion joints. I used just reinforced concrete with no rebar. No cracks in 10 years. That’s pretty much standard here with our hard clay soil. However, I agree with you that due to crappy tension strength of concrete, you should wait before driving a heavy load on it.
On crappy soil/base it really doesn’t matter how long you wait. It will still crack without structural reinforcement.
Mark
