Asphalt Spread Rate and Yield Check
The spread rate (lb/sy) a mat lays and the yield (sy/ton) a paving crew checks load by load.
Example
You enter
- Compacted mat thickness (in) 2
- Compacted HMA density (pcf) 145
You get
- Spread rate 217.5 lb/sy
- Yield 9.20 sy/ton
Details, formula, and sources
spread = thickness x density x 0.75; yield = 2000 / spread. A 2 in mat at 145 pcf lays 217.5 lb/sy and yields 9.2 sy/ton; a 3 in lift lays 326 lb/sy at 6.1 sy/ton. A low yield means the mat is running thick or the trucks are short. The mix design's compacted density governs.
spread_lb_per_sy = thickness_in x density_pcf x 0.75 (0.75 = 9 sf/sy / 12 in/ft); yield_sy_per_ton = 2000 / spread_lb_per_sy.
Asphalt spread / yield identity by name (spread = thickness x density x conversion; yield = 2000 / spread); first-principles unit arithmetic.
The spread and yield are public first-principles unit conversions; the compacted density comes from the mix design.
Estimate. AHJ and licensed professional govern.
Field names used by the API: thickness_in, density_pcf, spread_lb_per_sy, yield_sy_per_ton
- Density compacted HMA density from the mix design, ~145 pcf default for a dense-graded mixmix design
- Conversion 0.75 = 9 sf/sy divided by 12 in/ft; yield = 2000 lb/ton / spreadfirst-principles