How much per square foot?

At 6" deep, about 25 lbs per sq ft. A 10x20 ft driveway base needs approximately 2.5 tons of 3/4" RCA.

Is RCA as strong as virgin gravel?

Yes. FHWA studies confirm RCA meets AASHTO M-147 specs. Residual cement gives it self-cementing properties, increasing CBR values 10 to 15% over time.

How deep should the base be?

4" for patios, 6" for driveways, 8"+ for parking lots. Add 2" for clay soil with poor drainage.

Does RCA leach chemicals?

RCA has alkaline pH (8.0 to 11.0). EPA considers it safe for most uses, but avoid placing within 50 feet of acid-loving plants.

Self-cementing starts in 2 to 4 weeks. Full bonding takes 6 to 12 months, after which it becomes harder than traditional gravel.

Good for French drains?

Yes, 2 to 3" clean RCA provides about 40% void space. Wrap the trench in non-woven geotextile to prevent clogging. See our French drain calculator for sizing.

RCA comes from demolished concrete (gray, self-cementing). RAP comes from old asphalt (black, softens in heat, better for temp surfaces).

Cost savings vs new gravel?

RCA costs $8 to $15/ton vs $25 to $45/ton for virgin limestone. That saves $100 to $300 on a typical 10-ton driveway base.

ConcreteCrushed Concrete Calculator

Crushed Concrete Calculator

Estimate recycled concrete aggregate for driveway, shed, slab, and parking-pad bases.

Project Dimensions

Project preset

Driveway Base

6" compacted

Compacted base under asphalt, concrete, or gravel

Length (ft)

Width (ft)

Compacted Depth (in)

RCA grade

Ready to calculate

Enter your compacted base dimensions

Last updated May 29, 2026 by our expert review team

RCA Grades and Planning Use

GradeUseDensityPlanning note

3/4" minus RCA

Driveway and slab bases

1.35 tons/yd³

Fines help it lock up under compaction

1-1/2" minus RCA

Thicker bases and fill

1.30 tons/yd³

Larger pieces bridge soft areas better

2-3" clean RCA

Drainage and rough fill

1.25 tons/yd³

Better voids, weaker finished surface

Concrete screenings

Top dressing and leveling

1.40 tons/yd³

Fine material packs tight and can hold water

Expert Contributors

Creator

Ehsan Ghazanfari

Licensed Structural Engineer

Ehsan Ghazanfari

Licensed Structural Engineer

FISE-certified structural engineer with 11+ years designing bridges, retaining walls, and foundations. MSc from Aalto University.

See full profile

Expert Review

Cherry Jane Limbago

Licensed Civil Engineer & Master Plumber

Cherry Jane Limbago

Licensed Civil Engineer & Master Plumber

Licensed civil engineer and master plumber with 10+ years in structural design, estimation, and project management. Currently Project Engineer at Universal Robina Corporation.

See full profile

Updated May 2026

How we verify our calculators

Crushed concrete base planning diagram showing loose order amount, compacted RCA base, optional geotextile, prepared subgrade, and callouts for budget base material, fines, drainage, and lift compaction. — Order for the loose amount, then compact in lifts to the finished base depth. RCA is budget-friendly, but fines and drainage decide where it belongs.

RCA Base Decisions

Recycled aggregate, not decorative stone

Best use

Driveway, shed, slab, and parking-pad base where a recycled material is acceptable.

Check before ordering

Look for rebar, brick, asphalt, wood, drywall, and excess soil in the pile.

Fines and dust

Good for compacting. Poor for open drainage. Keep dusty RCA out of French drains.

Weak soil

Use geotextile as a separator so the base does not mix with soft subgrade.

Pro Tips

Ask for a small sample before a large order. Good RCA should look mostly like crushed concrete, not mixed demolition debris.

Use minus material for base layers. The fines help the base lock together after moisture and compaction.

Compact in shallow lifts. A thick loose pile may look solid on top while the bottom stays soft.

Do not use dusty RCA as a drainage stone. Use clean larger material where water needs open voids.

If you need a quarry dense-grade base instead, use the Crusher Run Calculator.

For broader natural stone options, compare with the Crushed Stone Calculator.

How the Calculator Works

Enter the finished compacted depth you want. The calculator converts the area to volume, adds your overage allowance, then uses the selected RCA density to estimate tons.

Depth is compacted depth. A 6-inch driveway base is not the same as a 6-inch loose pile.
Minus material locks up. Fines help bases compact, but they reduce open drainage.
Supplier weight varies. Moisture, original concrete, and contamination can shift the tons per yard.

Formula

Cubic yards = Length x Width x (Depth in inches / 12) / 27

Tons = Cubic yards x RCA density x (1 + overage %)

Quick Reference

Driveway base: 6"
Parking pad: 8"+
Typical RCA: 1.35 tons/yd³
Truck load: 18 tons
Order extra: 10% typical

Crushed Concrete Estimates for Common Projects

Driveway Base

40x12 ft, 6" compacted, 3/4" minus RCA

Material: 13.20 tons

Volume: 9.78 yd³

A typical one-load delivery. Compact in two 3-inch lifts and shape for drainage before the surface layer.

Shed or Slab Base

12x16 ft, 4" compacted, 3/4" minus RCA

Material: 3.52 tons

Volume: 2.61 yd³

Good budget base when covered by a slab, shed floor, or pavers. Fabric helps over clay or disturbed fill.

Parking Pad

24x20 ft, 8" compacted, 1-1/2" minus RCA

Material: 16.94 tons

Volume: 13.03 yd³

Near a full dump load. Confirm truck access and compact in several passes while the material is damp.

Common RCA Mistakes

Ordering clean drainage stone for a base

Clean stone drains, but it does not lock up like minus RCA. Use the right grade for the job.

Skipping lift compaction

Compact every 3 to 4 inches. One pass over a thick layer leaves soft material underneath.

Ignoring fines

Dust helps compaction, but it can slow drainage and make runoff messy. Keep it out of open drains.

Trusting any recycled pile

Reject loads with wood, drywall, brick, excess asphalt, or exposed reinforcing steel.

Frequently Asked Questions

Is crushed concrete good for driveways?

Yes, as a compacted base. Use minus RCA, shape it for drainage, and cover it if you want a cleaner finished surface.

How deep should crushed concrete be?

Use about 4 inches for light shed or slab bases, 6 inches for residential driveways, and 8 inches or more for parking pads.

Does RCA drain well?

Clean larger RCA drains better. Minus RCA has fines that compact well but reduce open drainage.

Do I need geotextile?

Use it over weak, wet, clay, or disturbed soil to separate the base from the subgrade.

Is it cheaper than crusher run?

Often, yes. Crushed concrete is usually a budget recycled base, while crusher run is a quarry-produced dense-grade base.

Important Disclaimer

These estimates are for planning purposes only. Actual costs vary by location, material availability, and project complexity. Always get at least 3 local quotes. This calculator does not replace professional advice.