? Concrete Pad Question

[dcmac214]

How thick a concrete floor/pad is needed to park a 14K 5er?
Not looking to get into arguing over whatever the detailed engineering specifics are. Just want a general idea how much concrete I'll be buying if I decide to concrete the barn floor.

[jplante4]

In his first post the OP said

Not looking to get into arguing over whatever the detailed engineering specifics are. Just want a general idea how much concrete I'll be buying if I decide to concrete the barn floor.

About halfway down the second page the OP posted

Got what I need for now -- Thanks all!

Ans yet the argument that the OP specifically wanted to avoid went on for 5 pages. It must be winter.

CLOSED

[Ralph_Cramden]

Grit dog wrote:

bid_time wrote:

monkeygirl wrote:
I am a concrete guy of 30 plus years... make sure it is straight cement content. NO FLY ASH ...

Really, no Flyash? Maybe you can tell me why that is seeing that every professional organization such as ACI, ASCE, FHA, ACPA, all recommend a minimum of 15% flyash and preferably 25%. And before you comment, maybe you should look up ASR (Alkali-Silica Reactivity). And we won't even talk about GGBFS which is also used at up to 40% cement replacement.

No fly ash because this is rvnet. The land of ex-experts who don't know what they're talking about....

I'm in trouble! I've placed probably a half million yards of concrete in bridges, roadways, water tanks and treatment structures and dams, all with fly ash or slag or other pozzolans. C rap. I've been doing it wrong. Can't believe I believed all those specifications and my grad level concrete structures and mix design courses!

Thanks Grit dog, you made my entire day with that post.

[westend]

allen8106 wrote:
I am now in the process of erecting a new building. A combination RV storage and work shop.

I had a 5" floor poured for my 10,500 lb 5er.

Good choice! Did you remember to put the in-floor radiant water based heating in that? Maybe, Kansas doesn't warrant the installation of floor heating but there is a big difference in comfort if you work on that floor every day.

[mbrower]

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

[allen8106]

I am now in the process of erecting a new building. A combination RV storage and work shop.

I had a 5" floor poured for my 10,500 lb 5er.

[troubledwaters]

Ivylog wrote:
...This post is my opinion (free advice). It is not intended to influence anyone's judgment nor do I advocate anyone do what I propose...

I couldn't agree more!

[riven1950]

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.

[Cummins12V98]

" Last week I had a 12 yard concrete truck put the front tires on 48 hours old concrete...it was a front loader truck."

Are you talking RiteWay with the chute on the front? Personally never heard of a 12 yard mixer in that configuration!

[Ivylog]

Grit dog, the Romans used much the same and it's still in good shape 2,000+ years later. Modern day concrete will not last 100 years.

[Grit_dog]

bid_time wrote:

monkeygirl wrote:
I am a concrete guy of 30 plus years... make sure it is straight cement content. NO FLY ASH ...

Really, no Flyash? Maybe you can tell me why that is seeing that every professional organization such as ACI, ASCE, FHA, ACPA, all recommend a minimum of 15% flyash and preferably 25%. And before you comment, maybe you should look up ASR (Alkali-Silica Reactivity). And we won't even talk about GGBFS which is also used at up to 40% cement replacement.

No fly ash because this is rvnet. The land of ex-experts who don't know what they're talking about....

I'm in trouble! I've placed probably a half million yards of concrete in bridges, roadways, water tanks and treatment structures and dams, all with fly ash or slag or other pozzolans. C rap. I've been doing it wrong. Can't believe I believed all those specifications and my grad level concrete structures and mix design courses!

[Grit_dog]

larry barnhart wrote:
I did our extension on the side of our driveway in 1998 doing 5" of concrete and 1/2" rebar at 20" square. I ran an 36 " pattern roller over for a design and saw cut at 9ft on the straight line from the roller. No cracks but last winter something happened that I can't explain. On one area the concrete had a dark look and has flaked in that area. I cured it as good as can be done. No idea what was the reason.

chevman

Surface spalls on wet finished surfaces (slabs) is caused primarily by a few things or combinations of them.
Too much water used as a finishing aid.
Freeze thaw cycling (exaggerated by ^)
Chlorides deteriorating the surface. (Salt/de icers)

Has very little to do with curing methods.
If the concrete is new(er), it was likely too much water during floating or troweling.

[larry_barnhart]

I did our extension on the side of our driveway in 1998 doing 5" of concrete and 1/2" rebar at 20" square. I ran an 36 " pattern roller over for a design and saw cut at 9ft on the straight line from the roller. No cracks but last winter something happened that I can't explain. On one area the concrete had a dark look and has flaked in that area. I cured it as good as can be done. No idea what was the reason.

chevman

[Cummins12V98]

cummins2014 wrote:

Cummins12V98 wrote:

newman fulltimer wrote:
8 inches down the center drive on area 6 on non weight area

For a RV???

Thats what I was thinking. I have had two RV pads on two different homes here in Utah, so there is the freezing issue. Both pads were poured with 6 bag , and the standard 2x4 forming.

The first one in the late seventies did get some cracks, but held up well otherwise. The problem back then it seemed we just poured , with not enough expansion . My first one was 15 feet wide one expansion joint down the center, okay there ,but it was like around 50 feet long, with expansion joints around every 12 feet. Not enough, it has to expand.

My present RV pad is 80 feet from street to back of the house . Only 11 feet wide , expansion up the center ,and every 6 feet or so the length of it. So 5*1/2 x 6 foot sections. No cracks, other then where it cracked in the expansions. going on 18 years ,looks as good as it did new. Has had a 38' foot fifth wheel on it for the past 10 years. To add this driveway ,and RV pad was poured with fiber mess. No rebar.

I poured mine 3.5" thick with wire mesh and 6 sack mix 20 years ago and it still looks great. My Current RV ONLY weighs 23K.

[Ivylog]

riven1950 wrote:
Ivylog, Glad you are not doing my driveway. No way I would spend that kind of money and then park a 14K fiver on it after 5 days.

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.:S 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.