Hot Mix Asphalt Paving ingredients include asphalt binders, course and fine
aggregates, and mineral fillers. About 90-95% of the total volume of the mix
is made up of aggregates. Surfaces that we usually associate with gravel
buildup will usually be of a mix design that contains a high percentage of
course aggregates, and probably a degradation of binders though wear and
evaporation (petroleum products evaporate). There are various surface
treatments, ranging from sprayed asphalt, asphalt seals (fog seal), to
slurries of emulsified asphalts mixed with fine aggregates, that can extend
the life of paving by limiting water intrusion, and these are particularly
necessary as the mix begins to disintegrate.
I can think of no other activity that will degrade a paved surface faster
than autocrossing on it. The aggregates are literally being pulled from the
surface. Even high traffic-index truck traffic will not subject a surface to
the high shear of racing cars on it. So that's where the gravel comes from,
and that's why no matter how we sweep it, it reappears. It is just the
pavement breaking down. Irreparably.
With rough grading, but no curbs, gutters, marking, right now you can figure
about $3.00 per square foot in install a medium index (for large areas and
not a high traffic-index) parking lot. The lot at GGF to use an example is
550,000 SF (about 12.6 acres not counting the staging area). That's works
out to a little over $1.6M.
This is all pretty boring stuff but it begs a question that is interesting
( I've always found it very interesting anyway), namely : Why would anyone
let us do this to their lot?
Tony
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