Prevent cracking of concrete slab

[perky416]

My garage is built on a concrete slab. I am laying a channel drain out the front of the garage door. Also, the concrete slab in front of the garage was all chipped and damaged.

Using my cut off saw to get neat edges and then my pneumatic drill to break up the concrete, i have cut out a section the width of the garage door by around 0.5m, to give space to fit the drain and remove the damaged area.

The slab is around 50mm thick and there is no rebar in it.

When it comes to re-concreting the area after the drain is fitted, what would be the best way to prevent the concrete cracking throughout and especially at the edges where it will join the old concrete?

It isnt to take the weight of a car, the garage is storage only.

Thanks

 

[Harry Bloomfield]

The slab is around 50mm thick and there is no rebar in it.

50mm/2" is far too thin to support anything at all. It will crack.

 

[Deluks]

I'd use a very thin layer of foam to create a joint. Then grout or sealant in the crack.

 

[perky416]

50mm/2" is far too thin to support anything at all. It will crack.

The original 50mm slab has been there for about 20 years and hasnt cracked yet. Looks like it was poured directly onto the mud too. The only damage was chipping to the surface out the front of the garage.

 

[Harry Bloomfield]

The original 50mm slab has been there for about 20 years and hasnt cracked yet. Looks like it was poured directly onto the mud too. The only damage was chipping to the surface out the front of the garage.

It would not last a week here, you must have exceptional ground conditions. My base is 5" thick, and still cracked.