Better Roads, June 2012
Road Science
By Tom Kuennen, Contributing Editor
As pavement preservation techniques tighten their beachheads in state, county and municipal road
agencies, new attention is focused on surface treatments, thin asphalt surfacings and the asphalt emulsions that make them possible.
Asphalt emulsions – mixtures of liquid asphalt and water – make expensive liquid asphalt go farther, covering far more square yardage and aggregate surface area for asphalt pavement preservation surfacings than possible with thicker lifts of hot or warm mix asphalt, all things being equal.
While they don’t add structural value, these thin surfacings aren’t intended to. Instead they protect aging asphalt pavements, seal cracks, retain aggregate, waterproof pavement structure, enhance friction, and with rejuvenators, give new life to an aged, oxidized asphalt surface. Emulsions used in full depth reclamation (FDR), though, can add structural value to a pavement structure.