Slab on Grade Construction without Control Joints

[bigmig]

I had a contractor approach me who told me about a residential floor system he poured, without control joints.
The slab is the finished floor. They polished it. They basically cure it slowly, misting it with water daily for about 3 weeks.
If/when the slab does crack, they router out a minimal amount of material and epoxy it, then polish it again, giving
it the appearance of basically a granite stone.

He said that large warehouses and big box retailers are all pouring their floors without joints, because the shopping carts
and castor wheels hate joints. Also the cost benefit of not having joints is apparently significant on these large projects.

I researched it, and sure enough, that is how they do these boxstore slabs.

https://www.concreteconstruction.net/how-to/materials/floors-without-joints_o

My question is in regards to smaller, residential construction. Has anyone done this? Are there design guides?

Thanks in advance.

 

[MIStructE_IRE]

Large warehouse jointless floors aren’t simply large concrete pours where we don’t bother with joints. Its a specialist system if you go entirely jointless on a large warehouse. So that’s not comparable to domestic.

With standard concrete/mesh in a typical domestic you might get lucky without joints. More often than not though it will crack. On grade, it can’t fall down, and without brittle finishes, a contractor might say - well who cares if it cracks.

I don’t think he’s going by a “design guide” he’s saying he doesn’t bother with joints, sees what happens and patch repairs it as it happens. Its one way to do it… I suppose…

By that logic though why not try out smaller timber joists in the upper floors? If they don’t work, then just repair those floors too as the cracks happen!

 

[dik]

MIStructIRE...Can you recommend a publication on large warehouse jointless floors?

thanks.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[MIStructE_IRE]

TR34 is my go to document for all warehouse slab designs. The last huge jointless one I did though was an entirely specialist design and it was basically an asphalt road buildup!

 

[dik]

Thanks...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[rscassar]

my clients absolutely hate seeing cracks in slabs on ground to the point the expectation is nearing crack free slabs. With the exception of sawcutting, tooled joints or control joints with provide the visual appearance of being straight. For a residential slab, how far are you trying to go between control joints. Most residential slabs I've seen have not been that large and generally can be down without a control joint, higher reinforcement requirements to control cracking. With the exception of internal to external slabs, where a control joint with dowels is provided for articulation for the external slabs.

 

[blihpandgeorge]

as already said large warehouse floors dont have joints (well larger spacing joints) as they are actively designed, whereas alot of domestic houses use simpler approaches. With fibre replacement, generally up to 20-25m seems the norm (in Australia). With PT can be further. The costs of joints, and specifically their maintenance when they get damaged by forklifts and /or need to have sealant replaced, can be huge.