Densegraded

Densegraded refers to a category of granular materials, particularly asphalt mixtures, characterized by a dense, continuous particle-size distribution designed to produce a tightly packed skeleton. It is used to achieve high stiffness, low porosity, and good durability under traffic.

In practice, dense-graded mixes include aggregates ranging from coarse to fine that fill voids created by larger particles, resulting in a relatively low air-void content after compaction. The gradation is determined by sieve analysis to meet a target envelope that prevents large gaps (gap-graded) or excessive fines that would reduce workability. Dense-graded materials aim for a well-balanced combination of strength and constructability.

Dense-graded asphalt concrete (AC-D) is the most common application, used for wearing courses and foundations in highways and airports. The dense packing yields improved rut resistance, load transfer, and moisture resistance compared with open-graded or gap-graded mixes. However, dense-graded mixes tend to have lower permeability and may require more robust compaction and quality control.

Standards and design methods governing dense-graded mixtures vary by country but typically rely on gradation requirements, compaction targets, and performance-based specifications. In asphalt, design procedures often reference established methods such as Marshall or Superpave, adapted to meet dense-graded gradation envelopes. Densegraded materials are contrasted with open-graded or gap-graded alternatives used where drainage or permeability is desired.