Asphalt Paving in Arkansas

An overlay is a new lift of asphalt bonded on top of the old surface. It replaces the wearing course and nothing below it. Full depth means the old pavement comes out, the base gets rebuilt and compacted, and the lot goes back new. What decides it is what is failing. Raveling, oxidation and shallow surface cracking are wearing course problems and an overlay answers them. Alligator cracking, rutting that moves under load, and areas that stay soft after rain are base failure, and asphalt laid over that reflects the same pattern back through. Core cuts tell you the existing thickness; the surface will not.

Asphalt is a flexible pavement. It does not span a load the way a concrete slab does; it spreads the load down into the base and the subgrade. The base carries your lot and the mat on top distributes. Water is what takes the base away. A base holding water gives up bearing strength, the pavement flexes further under every truck, and repeated flexing is what produces alligator cracking. Standing water also drives moisture into the mat and strips binder off the aggregate. Grade, and where water leaves the lot, decide how many years you get more than the thickness of the asphalt does.

Asphalt gets its strength from density. The mix goes down hot and the rollers squeeze the air out of it. Air voids left in the mat are open routes for water and oxygen, which is why an under-rolled lot ravels and grays early even where the base is sound. Compaction only happens inside a temperature window: once the mat cools below roughly 175 to 185 degrees, the rollers stop gaining density. Cold days, thin lifts and long hauls all shorten that window because the mat cools faster. The longitudinal joint between passes is the lowest density part of any lot, and it usually opens first.

Asphalt does not cure the way concrete does. It stiffens as it cools, so the wait before traffic is a cooling question, and a thick mat on a warm night holds heat longer than a thin one in the fall. A new lot also stays soft for its first weeks in service: power steering turned against a stopped wheel, trailer jacks and dumpster casters all leave marks in it. The first seal is a much longer wait. Fresh binder is still giving off volatile oils and sealer will not bond to a surface doing that, so the first coat waits for the mat to weather through a season.

Square footage is the starting point, not the answer. Thickness follows the load: a lot that takes loaded delivery and trash trucks needs a deeper section than one that only sees cars, and every added inch is more tonnage. Then there is what has to happen first, removal and haul off of the old pavement, stone brought in to rebuild a soft base, grade or drainage correction. Layout moves it too. Tight islands, curb lines and phasing to keep half your lot open all force handwork and repeat mobilizations instead of a paver running long passes. Asphalt binder is refined from crude, so material pricing moves with oil.