Job mix formula, the target gradation, binder content and volumetric properties approved for a specific mix on a specific contract. It comes from the lab mix design, often adjusted after a plant trial, and production tolerances on each sieve and on binder content are measured from it. Changing aggregate sources or RAP percentage usually means a new or revised JMF before paving continues.
The JMF calls for 5.4 percent oil and 20 percent RAP, so don't let the plant sneak the RAP up to 25 without paperwork.
Also heard as
- job mix formula
Related terms
Gradation
The distribution of particle sizes in an aggregate blend, reported as percent passing each sieve.
QC/QA
Quality control and quality assurance: contractor testing to run production and agency testing to verify it.
Superpave
The performance-based system for grading binders and designing asphalt mixes around climate and traffic.
RAP
Reclaimed asphalt pavement: old asphalt milled or crushed and fed back into new mix as aggregate and binder.