Tell me what you see here?

[Hay Dude]

I realize the question posed is "what do you see here"...but what I see "here"...is a bunch of amateur armchair engineers...!
There is really no information on the actual mix of the concrete for all we know it could have been a high PSI mix to allow for a wet, easy to place pour...it could also have had fiber along with a rich Portland content which greatly increases the tinsel strength of the slab eliminating the need for wire etc...

As for the rebar...for the most part unless there is a deeper "stiffener" required for specific load bearing purposes etc. most slabs do not even require a rebar grid (wire mesh and or fiber is all that is required to obtain the required strength)...there are millions of basic floor slabs designed by engineers and architects where no rebar was/is required..in a majority of cases rebar for this type of application is merely overkill...

I'm not saying the above is the case it does look like a lousy, amateur job but you can't always base things on the way they appear...

Control joints are often sawed shortly after the pour is made...

I always base things on the way they appear. In fact, I always say I see better than I hear
Also, Im not an armchair engineer. Ive done hundreds of pours for house basements, garage floors, patios, and covered porches. Ive dug and poured miles of footings dating back to when I was 14-15 years old working for m dad.
I know bad construction techniques when I see them. If rebar wasnt necessary because high/early mix was used or fiber was added, then why even use rebar? Also the rebar wasnt drilled into anything for edge support. It was just laid on the floor with no chairs.
That wasnt a total disaster, but it was below average.

 

[k0ua]

Gee and here all this time I thought concrete work was hard.....

That is just what "they" want us to think. But that contractor finally "came clean"

 

[5030]

No ties. First time I've ever saw that.

No rat wall either. That don't fly around here. Code is at least 4 feet around the perimeter including any door openings. When I poured my shop floor for the new machine shop, I used cattle panels instead of rebar and stood the PEX off the panels with plastic standoff's.

No 4" or 6" either, 10" thick, 4 bag mix. I have heavy machine tools on it. In the winter, I keep the floor at 70 degrees. Floor heat is wonderful.

 

[/pine]

I always base things on the way they appear. In fact, I always say I see better than I hear
Also, I知 not an armchair engineer. I致e done hundreds of pours for house basements, garage floors, patios, and covered porches. Ive dug and poured miles of footings dating back to when I was 14-15 years old working for m dad.
I know bad construction techniques when I see them. If rebar wasn稚 necessary because high/early mix was used or fiber was added, then why even use rebar? Also the rebar wasn稚 drilled into anything for edge support. It was just laid on the floor with no chairs.
That wasnt a total disaster, but it was below average.

FYI...on most non structural slab (floor) pours...rebar is NOT required...in most cases its only purpose (like wire mesh) is to prevent cracks from separating after the fact...owner/builders (mostly amateurs) use rebar simply because they don't know any better...In most cases a 4" slab (typical floor slab) is too thin for rebar to be effective anyway...(do some research)

As for experience I was a GC (class A) in FL for over 40 years...I was responsible for untold tons of concrete in every application imaginable short of the Hoover dam etc from DOT bridges (state contracts) to untold work at Disney etc......99.999% of the jobs were designed by either an architect or engineers or both...the only nonstructural floor slabs where rebar was specified were built on swampy ground...Did build a few high end homes with "safe rooms" but they were far from typical...

What's funny is someone (like an amateur owner builder) sees someone who is uninformed putting rebar in their slab they think it's the rule...small time sub contractors are no different especially the ones that rarely if ever see a professionally designed (by an architect etc.) structure...most would not know a "specifications plan" from a roll of felt...!

 

[fatjay]

To me, rebar is cheap insurance. Sure isn't going to hurt anything. Rebar vs no rebar, after 20 years there may be 3 cracks vs 10. Has anyone poured 2 identical slabs and compared them years later on a similar substrate in a climate with an annual 100 degree temperature swings and similar abuse.

Point is you spend thousands of thousands of dollars on a slab, $150 on rebar and a couple hours on ties really going to make a difference in over all cost?

 

[Hay Dude]

Again, I said IF (We don’t know) fiber reinforced concrete WAS being used, rebar may be pointless. Going further, Laying rebar on the ground makes the exercise even more pointless. Im agreeing with you, /pines, or maybe you don’t realize that? I know rebar isn’t needed everywhere and on large jobs can make bidding less competitive. Get in, get the job, then cut corners until you can pack up and leave. Then when the concrete cracks, blame settling ground or use some other BS excuse.
No, I look at rebar as an optional way to make concrete stronger, even if it’s not shown as needed on the prints. If my customers want it, it goes in, but needs to go in properly, unlike demonstrated in the barn slab. If the ground is not virgin or compacted soil or were building over anything soft, or questionable, it gets rebar. As was said in #45, it’s cheap insurance. I also pour 5” thick most everywhere now.
I know what I’m doing and Im really not impressed or intimidated by anyone’s background, especially internet experts.
I’ve never had a concrete failure in 35 years, so I must be doing it right.

 

[/pine]

Again, I said IF (We don稚 know) fiber reinforced concrete WAS being used, rebar may be pointless. Going further, Laying rebar on the ground makes the exercise even more pointless. Im agreeing with you, /pines, or maybe you don稚 realize that?
I look at rebar as an optional way to make concrete stronger, even if it痴 not needed. If my customers want it, it goes in, but needs to go in properly, unlike demonstrated in the barn slab. If the ground is not virgin or compacted soil or were building over anything soft, or questionable, it gets rebar. As was said in #45, it痴 cheap insurance. I also pour 5 thick most everywhere now.
I know what I知 doing and Im really not impressed or intimidated by anyone痴 background, especially internet experts.[/B}
I致e never had a concrete failure in 35 years, so I must be doing it right.

Actually in the OP's case a well tied grid even under the slab would offer a minor amount of support compression wise but being a typical nonstructural floor it is a moot point...because it was not suspended in the pour it is of zero worth for preventing cracks from widening which is the only reason an architect or engineer would spec it...!

I only cited personal experience because you did...

 

[fatjay]

If you're going to use rebar do it right. You don't pour a slab that size without putting something heavy on it. Why go cheap or cut corners when you have to live with it for many years.

 

[redman135]

One thing nobody mentioned was the concrete thickness at the door, it appeared to be 3" max. Also in my area it is standard practice to ramp the concrete from the outside level, UP to the floor level, the ramp section being a 2" lift and in about 12". This is to stop wind driven rain getting inside and flooding things. Also bouncing up that step will get old fast.

 

[Hay Dude]

I park 3 heavy farm tractors, a round baler, a square baler, 15’ bush hog and a hay mower in a barn about that size, so what may be called non structural is sure supporting a heck of a lot of weight! Probably 40-50 tons. I’d want rebar for SURE. Especially if the ground is disturbed or soft to begin with