I was recently contacted by a colleague who advised that a contractor for his project used a few pounds of sugar (purchaed from a nearby grocery store) to prevent concrete from curing. The concrete was placed for a communications manhole afterwhich it was realized it had the wrong compressive strength. Using the sugar allowed the placed concrete to be easilly removed in a viscous state (versus use of a jack hammer).
Anyone previously encounter a previous situation? I'm assuming that the sugar reacts with the cement such that the hydration process is negated.