Small quantity of concrete and stone -potential hardcore? (Fords Farm RG31)

3 large pieces of concrete which were dug out of a flower bed where nothing would grow well: they must have been dumped there by builders when the house was built!? Other concrete pieces are a broken bird bath. See pics - watering can and plant pot are in photo 1 for 'scale' only. I cannot lift the pieces nor do I have a sledgehammer to break them up but am hoping someone can use them. 🤞🙏