Paving Glossary

Bottom structural asphalt layer (thickest). Provides the primary load-bearing capacity for the pavement structure.

Roller passes to reach target density; measured by stick check. Typically requires 95-100% of max dry density per GDOT specs.

Spread rate tolerance table. Base: ±55 lbs/SY, Intermediate/Wearing: ±27.5 lbs/SY, OGFC: ±7 lbs/SY, PEM: ±10 lbs/SY from designated rate.

Minimum air temperature table for asphalt placement. Specifies required temperatures based on lift thickness (e.g., 1 inch or less requires 55°F minimum).

Middle layer between base and wearing course. Provides additional structural support and smoothness.

Pounds per Square Yard. Standard unit for spread rate (how much asphalt per area). Controls thickness and density of the asphalt mat.

Single layer of asphalt placed in one pass. Multiple lifts may be used to achieve total pavement thickness.

Material Transfer Vehicle. 24-ton machine that sits between the dump truck and paver, providing continuous material flow and remix action.

Open-Graded Friction Course. Porous asphalt surface mix that allows water to drain through, improving wet-weather traction.

Polymer-Enhanced Membrane (also called Polymer-Enhanced Mixture). Asphalt surface treatment that provides enhanced durability and resistance to cracking.

Heated plate on back of paver that levels and smooths the asphalt. Controls the final mat thickness and surface texture.

How much asphalt per square yard (lbs/SY). Controls thickness and density. Calculated as thickness (inches) × 110 lbs/SY per inch.

100 linear feet of road. Standard civil engineering unit for measuring roadway distances.

Manual thickness measurement of asphalt mat behind the screed. Measures loose material height to verify proper compacted thickness (loose height = compacted × 1.25).

Square Yard. Equal to 9 square feet. Standard unit for paving quantities and area calculations.

Asphalt emulsion sprayed on existing pavement to bond new layer. Application rate varies by surface condition (typically 0.04-0.12 gal/SY).

Volume of emulsion applied per square yard before paving. Must be within GDOT Table 2 range for the surface type being bonded.

Nominal tons per dump truck, typically 18-20 tons. Actual capacity varies by truck and local regulations.

Top surface layer that traffic contacts directly. Must meet friction, smoothness, and durability requirements.