Futurology

From https://steemit.com/chemistry/@pinkspectre/sugar-sabotage

When you add water to dry concrete mix, it reacts with chemical components of the cement - calcium, silicon and aluminum oxides - to form a paste which thickens around the aggregate, binding it together as the mixture hardens. Without this hydration reaction, the concrete can't properly bind and remains soupy. Sugar molecules interfere with this process, possibly by preventing the particles in the cement from clumping. However, there may be a more chemistry-based explanation. Aluminum and calcium can react with sugar to form insoluble chemical complexes, meaning they cannot be readily dissolved in water

Apparently, refined white sugar works best, while lactose has only minor effects. Setting can be increasingly delayed by adding more sugar, up to 1% of the cement volume. After this, the concrete will not harden at all! I learned about this from a facebook-circulating antifa post, with the intent of getting activists to use sugar to sabotage a border wall