Concrete slab - what options to renew?

[PhoenixClose1]

There's a concrete slab in my backyard just outside the pergola and the garage.  It's been disintegrating for the past few years.

I'd like to fix it up, if it's something I can do myself (low intermediate handyman, but never worked with concrete before) .  I had thought of just removing or replacing with nice pavers it but realised the green fence is right on top of it. The slab goes around the fence's white posts.  I'm not comfortable touching that part.

So maybe I can refresh it with a layer of concrete on top and the sides?  The slab is not flat though. The lower right corner has probably subsided a bit and so the the diagonal crack has some sections jutting up (I tried to show this in the second picture).

- What kind of concrete should I consider?

- How do I flatten the surface?   

(And just curious, how might a professional fix this)

Thanks

[MitchellMc]

Hi @PhoenixClose1,

I believe a professional would cut along the fence line and remove the broken slab. They'd then compact the ground to prevent further subsidence and pour a new slab in its place. You can't add more concrete over the slab in its current condition, as further movement will simply crack your repair job along the same fault lines. Given the extensive subsidence and cracks in the slab, I'd recommend replacing it as the best option. Here's a helpful step-by-step guide: How to pour a concrete slab.

Please let me know if you have any questions.

Mitchell