Hi @Cashrob,
A warm welcome to the Bunnings Workshop community and thank you for your question.
I'm struggling to visualise what you are trying to achieve. Is it possible to get some photos of the location of the pathway and a few details about how you intend to use the broken tiles and broken shells? Let me know if you need a hand uploading images, I'm happy to help if required.
I believe what you are looking to make is along the lines of a crazy paver pathway. You might like to start by checking out How To Lay Crazy Paving.
Is the plan to use the broken shells in the grout lines between the tiles as an aesthetic feature? Or were you hoping to use them as a compacted base material?
Typically, a pathway will start with a compacted base such as the one you'll see in How To Prepare And Lay a Base For Pavers.
I wouldn't be confident you could achieve enough compaction with crushed shells to make something that will last, so a compacted layer of road base or drainage gravel would be a good starting point.
What kind of broken tiles have you got? Are they porcelain, ceramic, natural stone, or maybe concrete pavers? The specifics will determine the best products to use.
The specifics of the project will determine the best products to use. Oftentimes mortar is the best option for setting your tiles or pavers in place, but I'd need to know what you are trying to achieve to say this with certainty.
Let me know what you think so far. I'm excited to help you out with your project.
Jacob
