Consolidates Crusher Run, QP, DGA, and 21-A road base.
Order loose volume × 1.25 (Compacted ÷ 0.80) to achieve specified target depth.
Standard loose stockpile weight; compacts to a dense structural matrix.
Mist with water and compact in thin lifts for maximum rigidity.
The Geotechnical Role of Dense-Graded Aggregate (AASHTO M147)
Crusher Run (also marketed regionally as Quarry Process, QP, Dense Graded Aggregate / DGA, or 21-A) is the backbone of civil road construction and professional hardscaping. While regional names differ based on local state Department of Transportation (DOT) gradation specs, all belong to the dense-graded aggregate family.
Unlike clean #57 stone where all fines have been screened away, crusher run is governed by AASHTO M147 (Standard Specification for Materials for Aggregate and Soil-Aggregate Subbase, Base, and Surface Courses). It contains a complete continuum of particle sizes ranging from 3/4-inch angular rock down to microscopic stone flour.
When rolled with a heavy vibratory plate compactor or roller, the smaller stone particles and rock dust are driven into the void spaces between the larger stones. This interlocking matrix produces high California Bearing Ratio (CBR) values, distributing vehicular wheel loads evenly across the subgrade.
Finished Compacted Volume (yd³) = [Length (ft) × Width (ft) × Compacted Depth (in)] / 324Quarry Loose Order (yd³) = Finished Compacted Volume ÷ 0.80 (equals Finished Volume × 1.25)Certified Scale Weight (Tons) = Quarry Loose Order × 1.45 Tons/yd³Contractor Compaction Protocol for Paver Patios & Driveways
- Excavation: Dig out native soil to target finished grade plus base depth. Crown the subgrade slightly to shed water away from foundation footings.
- Subgrade Stabilization: Lay a heavy-duty woven geotextile stabilization fabric (such as AASHTO M288 Class 1/2 woven). Woven fabric provides high tensile modulus and prevents soft subgrade soil from pumping up into the stone base under vehicular loads.
- First Lift (2 to 3 Inches): Spread crusher run in an initial 2.5-inch loose layer. Mist lightly with a garden hose until damp throughout.
- Plate Compaction: Make three overlapping passes with a commercial plate compactor (minimum 3,000 lbs centrifugal force).
- Second Lift: Repeat the process for subsequent lifts. Never attempt to compact a single lift greater than 3 inches thick, as plate vibratory energy cannot penetrate deep into loose stone.
Frequently Asked Questions About Crusher Run
How many tons of crusher run do I need for a 12x24 foot paver patio base?
A 12x24 foot patio equals 288 square feet. A standard pedestrian paver installation requires a 4-inch compacted base of crusher run. At 4 inches, net loose volume is 3.56 cubic yards. Factoring in a 20 percent mechanical compaction allowance under a plate tamper, order 4.27 cubic yards (approximately 6.2 tons of stone).
What is the difference between crusher run, quarry process (QP), and 21-A?
They are regional commercial trade names for the exact same family of dense-graded aggregates governed by AASHTO M147. Crusher run is common in the Midwest and South, Quarry Process (QP or DGA) is standard in the Mid-Atlantic and Northeast, and 21-A is the Virginia and Southeastern DOT designation. All blend 3/4-inch or 1-inch fractured stone with fine rock dust.
Why does crusher run need to be watered during compaction?
Adding a light mist of water lubricates the fine stone dust particles, allowing them to slide into the voids between the larger angular rocks. Water activates the binding properties of the mineral fines, allowing the plate compactor to achieve maximum Proctor density and creating a rock-hard, cement-like pavement foundation.
Can crusher run be used as the final visible surface on a driveway?
Yes, crusher run creates a solid, non-rutting driving surface. However, because it contains fine stone dust, vehicles will track white dust when dry, and heavy rains can create light surface slurry. Many homeowners top 4 inches of compacted crusher run with a 1.5-inch wearing surface of clean #57 crushed limestone.