Share
Welcome to the Bunnings Workshop community @tayeb. It's terrific to have you join us, and many thanks for your question about repairing concrete.
There appears to have been some subsidence in the area or a large tree root pushing up on the slab. Given that there is a height difference between the two sections of the broken slab, even if you were to fill the gap with something like expanding concrete of Sikaflex 11FC, that wouldn't really disguise the gap, but it might make it a little less noticeable.
The only real fix for the situation would be to enlist the services of a stabilisation company that would assess the slab and return it to level. The gap could then be filled. Be aware that this would likely be quite an expensive process.
Please let me know if you have any questions.
Mitchell
