I have a cast patio that has cracked along the sides. The patio is quadrangular and has a basement storage underneath, essentially an extension of the basement. Now that I've started removing the loose material along the sides, I see that it has been cast with concrete in different layers, with wet sand between the layers. I've also seen that there are small white plastic pipes embedded. Do you think it's possible to make the concrete adhere to the sand so it stays in place? Has anyone repaired something similar? The patio was built in the '60s.
