How to make them strong and truly durable for years and years. There was latex modified concrete and low slump concrete, but those materials lack flexibility and they add dead weight. Thin overlays are brittle, cracking easily especially in the winter cold, and the loss of aggregate made them too smooth too soon.
What is needed is a light weight thin overlay, twice as strong as concrete, with a surface skid number in excess of 50 even after years of grueling New York Traffic, and more importantly, with enough flexibility to resist reflective cracking even in frigid Minnesota winters.
A major technological breakthrough was required to produce a molecular marriage between the low temperature flexibility of the urethane system, and the strongest adhering, chemically resistant epoxy system.
