How does one keep floor crack from widening?

[428PI]

My current shop is made from an old chicken house. It aprox 19x40. The cement floor was poured years ago and is cracking in half. The crack is up to 1 inch side. I've put in quick cement aprox a year ago and it's starting to crack and widen perhaps 1/8 inch or so. Can one make a u shaped rebar "staple" to hold floor together? Someone suggested drilling straight down and putting down 3 ft rebar to the ground. My main building stem walls-foundation is rolling out slightly with time too and that's perhaps why the floor doesn't stay put. The wetness of the ground makes some difference in crack width. I don't really want to pour new floor. I'd probably put up new shop if that was the case.

 

[ItsNemo]

Is one (or both) side(s) settling and making a V shaped crack or are the two pieces actually moving apart?

If it's a V shaped crack your base is no good and you're going to have a heck of a time trying to stop it.

If it's two pieces moving apart, you could put dirt and/or pin something around the edges of the slab to make it stay put.

 

[Turbo]

If the stem walls are moving, sinking, forcing the edge down and cracking your slab, drilling holes and driving rebar in to it won't solve anything. To properly fix is to remove and replace. Can you support the structure and install a new stem wall and floor in a monolithic pour? Terry

 

[Lynden]

You could try "crack stitching".

https://www.google.com/search?q=con...AhWE3lQKHfHnBwwQsAR6BAgBEAE&biw=1305&bih=1170

https://www.rhinocarbonfiber.com/products/concrete-crack-lock/

https://www.google.com/search?client=safari&rls=en&q=concrete+crack+stitching&ie=UTF-8&oe=UTF-8

 

[428PI]

Thanks Lynden. I didn't even know they made such a thing. Now, I just have to get a grinder to make the slots. I just bought a large hammer drill and bits for the job.

 

[Lynden]

You're welcome. I have the same problem in my garage, but the crack is at the cut/fill line in the subgrade and there is some differential settlement in the slab. My only solution is to remove and replace half the slab.

If you haven't used your hammer drill, I suggest you return it and get a rotary hammer. I have a 1-Inch Bosch Bulldog, but there are less expensive options (maybe a reconditioned Bosch or Milwaukee).

https://www.cpooutlets.com/factory-...rotary-hammer/bshr11253vsr-rt,default,pd.html

https://www.cpooutlets.com/factory-...MIl6_Pobby3QIVgq_sCh3lBwGZEAQYASABEgKLuPD_BwE

 

[driz]

Thanks Lynden. I didn't even know they made such a thing. Now, I just have to get a grinder to make the slots. I just bought a large hammer drill and bits for the job.

If your drill isn’t happy try an air chisel. Yea , no **** it sails through even hardened old concrete even shale heads. Especially handy when your drill centers up on a [emoji51]Biggs’s piece of aggregate You can get pretty nice precise cuts with the taper tip.


Sent from my iPhone using Tapatalk

 

[428PI]

I bought a Harbor Freight rotary hammer max sds for 99 bucks with my club discount with a set of 3 drill bits and 3 chisels.

 

[dfiler2]

A 4 or 4 1/2 inch grinder with a diamond blade will make short work of the slots.

 

[1953mercury]

As is often the case, it sounds like you are suffering from poor ground conditions below your slab and stem wall. Most likely the slab was poured right over accumulated chicken s**t and other organic matter. If you repair it in one area, it will most likely just crack in another. I think Turbo above has the proper solution. Remove the old slab and knee wall, remove any and all organic material down to a solid base, fill with a non compactable material like washed or screened rock, and use #4 rebar in a 18" grid with a 4" minimum pour. Mike

 

[428PI]

1953mercury. You're probably right about the chicken s...t etc. I'm guessing it was poured in the 60s or so. My main concern with the floor now is keeping the crack reasonable so my creeper wheels won't get caught in the hole. With the rain we've been having the crack has lessened. Has survived with no reinforcement that I can see. The crack has taken 20 plus years to equal 1 inch. Here's a picture of the cracks and the middle drain that I filled with quickcrete.