fixing cracks in concrete

[cutthroatxxx]

Hello all,I have a 12x20 pad that has a crack that runs the whole 12 ft length.I know most people will say tear it out but Im not gonna do that right now.I have 3 of these pads that used to have machine sheds on them&Im gonna build some new ones.About 6 years ago one had the same crack almost,what I did was clean it really well&used some quilkcrete&it has held up.Im wondering is there any other tips anyone has for prep to insure I get more life out of it?
Its a really thick slab maybe 6-8 inches.Im doing my shop floors with the epoxy in the next week or two&if I have enough left Id like to do this pad with it as my plan is to turn this one into a sewing room for my wife&atleast 1 machine shed were debating the other for man cave,guest house or another machine shed.If I rember right frk back when I was in construction a guy who was doing some concrete repair@a job we were on would use a chisel&make the hole bigger on the inside then sandblast it with a spot blaster&blow it out with air.That was 15 or 20 years ago so Im not 100% on that.

 

[ConCretin]

It depends on the nature of the crack and the reinforcing (if any) in the slab. More information and pictures would result in more useful answers to your question.

Otherwise you're just gonna get "there's only two kinds of concrete..........."

 

[cutthroatxxx]

My grandfather leveled it used gravel&then I know he used rebar I cant remember if he used mesh or not.He built the house&all of the out buildings by his self he never took shortcuts.But thats about all of the info I have sorry.

 

[pauloman]

do it it way they repair airport runways after making cuts etc. to run wires.... Sand and epoxy to make epoxy cement..... - something like Epoxy Mortar Patch (tm) with local sand

 

[danieldd]

Try "Crack Weld",

http://www.radonseal.com/crack-injection/slab-cracks.htm

I had multiple small cracks in my newly formed concrete. Its a specialy formulated 2 part resin. You clean the crack, apply resin to the crack, rub sand into the crack - ten minutes later, take a strong putty knife and knock down the excess.

Seems to work rather well. I remember seeing a youtube application for this. They advertise the resin is stronger than the concrete.

One caution though - you have to work fast as the resin sets up kinda quickly. Also, you'll have to trash the mixing nozzle once you get done as its not feasible to clean it. I bought extra ones as they're relatively cheap.

Good luck!

 

[cutthroatxxx]

Thanks.Ive never heard of epoxy cement or the concrete weld.

 

[LegacyIndustrial]

Cutthroat, we have a product specific for this:
Link: http://legacyindustrial.net/cart/hd821-crack-sealant-gel-style-p-94.html

 

[AlphaGarage]

If it a wide fissure you might want to consider an epoxy binder mixed with sand. A one gallon kit of our's (TrowelEase) mixed with 50 lbs. of sand will fill a 6' x 6' area about 1" deep. It's very durable, used for repairing loading docks etc.

For smaller cracks, and ones that may expand or contract, look at IntegraFlex, a 100% solids epoxy that retains some flexibility even after it's fully cured.

BTW, a good epoxy can help prevent small cracks from expanding and even from forming to begin with.

 

[got2boostit2]

Good information, subscribed.

 

[jose jj jacinto]

the best use on this is using a two part structual epoxy. this is stronger than concrete when fully cured, and will hold up for what you need it for.
the materials, i have a person that sells direct to the public as well. you dont need any special tools or euipment, mostly items taht you probably have accumalated over the years.

 

[cbracer]

I'm buying this stuff today from a local supplier:
http://www.concretemender.com/

Was going to do this, and it's a bit cheaper but doesn't have as low of viscosity:
http://www.grainger.com/Grainger/STRONGTIE-Crack-Injection-Resin-2WLG3?BaseItem=11C302

some others that are shipped only:

http://www.radonseal.com/crack-injection/slab-cracks.htm

http://www.foundationarmor.com/armor-fs90-concrete-repair-kit/

 

[CNGsaves]

You've had enough posts so surely you've seen this already . . . . . something like this really needs visual . . . so here you go: