Hi @jancleland,
A warm welcome to the Bunnings Workshop community and thank you for your question.
As the cracking appears to be from movement, any repair would only be aesthetic in nature and further cracking is likely to occur. If you would like to fix the issue once and for all, then this would likely require the removal and replacement of the concrete slab.
If you are fine with an aesthetic repair, there are no issues using a concrete repair product like this Sika 1L High Strength Epoxy Repair Adhesive Concrete Fix Kit, but with any further movement of the concrete, more cracks are likely to appear.
Start by pressure cleaning the surface and removing any loose material from the cracks.
As the cracks aren't particularly wide, you may need to widen them using an angle grinder with a Flexovit 105mm Turbo Diamond Concrete Grinder Blade.
Once prepared, mix the two-part concrete repair mix and apply it to the cracks and holes with a 100mm Sharp Edge Paint Scraper, doing your best to smooth it as you go.
You can also tape off the cracks with painter's tape to get cleaner lines.
Let me know what you think and if you have further questions, please don't hesitate to ask.
Jacob
