Recipe for unsettable concrete powder

I spend a lot of my time in my forever world making coloured beaches (like the pink ones in the Caribbean) using concrete powder. because beaches are connected to water it means you have to use a block to form a barrier to prevent setting - usually i use wool but it can look a bit janky depending on the colour. it's also really annoying because once the powdered concrete touches water, the setting can't be reversed so mistakes mean I have to gather even more powder, which can be tedious as sand and gravel aren't renewable.

In real life, concrete can be prevented from setting using sugar. Adding a recipe like waxed copper for unsettable concrete powder would increase the block's versatility and ease of use. It would also allow the addition of rain setting regular concrete powder, which could make mass-setting concrete less tedious, without interrupting people who do want to use concrete powder as a building block.

Thank you for considering! :]