Splicing concrete floor

[goranr]

Inspired by the "Splice Concrete" post, I'm wondering:
My garage floor is cracked and has been pushed up a little right at the door (about a 50x150 cm area is "loose"). Cast slab without insulation (1960s).

How do I repair this? My thought is to remove the loose piece and cast new, but will it adhere to the old concrete?

Best regards

 

[goranr]

Inspired by the "Skarva betong" post, I'm wondering:
My garage floor is cracked and has been slightly pushed up right at the door (about a 50x150 cm area is "loose"). Poured slab without insulation (1960s).

How do I repair this? My thought is to remove the loose piece and pour new concrete, but will it adhere to the old concrete?

Best regards