Crushed Concrete Compaction Factor: What You Need to Know
Whether you're building a driveway, prepping a base for hardscaping, or backfilling a site, understanding how crushed concrete compacts is key to the long-term success of your project. At Ottr, we help you not only get the materials delivered fast — but also understand how to use them right.
What Is Crushed Concrete?
Crushed concrete (also known as recycled concrete aggregate, or RCA) is created by processing reclaimed concrete from demolition sites. Once crushed and screened, the material becomes a reliable, eco-friendly alternative to virgin aggregate — and it's widely used as:
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Base material for driveways and patios
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Structural fill for construction sites
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Backfill around foundations and retaining walls
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Pipe bedding and drainage layers
What Is Compaction Factor, and Why Does It Matter?
Compaction factor refers to how much a material compresses when it's compacted — and it plays a major role in:
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Load-bearing strength
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Long-term stability
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Water resistance
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Settling over time
For crushed concrete, a good compaction factor means you're creating a solid, dense base that won’t shift, sink, or absorb excess moisture. Poor compaction, on the other hand, can lead to costly repairs, uneven surfaces, or structural failure.
Typical Compaction Factor for Crushed Concrete
When compacted with a mechanical compactor, crushed concrete typically achieves 90–95% of Standard Proctor Density — making it comparable to, or even better than, many natural aggregates. This assumes:
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Well-graded material (including fines)
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Moisture content near optimal levels
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Proper equipment and technique used
💡 Pro tip: When planning a project, account for 10–15% reduction in volume after compaction. If you’re ordering 10 cubic yards of loose material, you may only end up with 8.5–9 cubic yards once compacted.
What Affects Compaction Performance?
Several variables influence how well your crushed concrete will compact:
✅ Particle Size Distribution
A good mix of coarse and fine particles creates better interlocking and fewer voids — resulting in tighter compaction.
✅ Moisture Content
Too dry and it won’t compact properly. Too wet and it can become mushy. Crushed concrete compacts best at slightly damp moisture levels.
✅ Compaction Method
Use a vibratory plate compactor or roller for the best results. Hand tamping is not effective for large areas or deep layers.
✅ Layer Thickness
Compact in layers (lifts) of 3–6 inches at a time. Trying to compact too much depth at once will lead to uneven density and soft spots.
How to Improve the Compaction Factor
Want to get the most out of your crushed concrete? Here are a few simple ways to boost compaction:
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Moisten before compacting (if the material is dry)
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Use proper machinery — like a vibratory plate or roller
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Compact in layers — never dump and compact all at once
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Choose fines-rich crushed concrete for better interlocking
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Avoid mixing with debris — trash, roots, or chunks of asphalt can reduce compaction quality
Why Buy from Ottr?
Not all crushed concrete is created equal. At Ottr, we only deliver screened, quality-controlled material — never the sloppy, oversized mix that makes compaction a nightmare.
We make it easy to:
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Order crushed concrete online by the yard
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Use our calculator to estimate quantity
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Schedule your delivery date during checkout
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Message our team with site-specific questions
We’re here to help you build it right — from the first yard to the final compaction.
Final Thoughts
The compaction factor of crushed concrete plays a critical role in project durability, strength, and water resistance. Whether you're building a structural foundation or just a solid backyard patio base, understanding compaction helps you avoid surprises down the road.
Choose high-quality RCA, follow proper compaction techniques, and you’ll have a foundation that holds up for years.
Order Crushed Concrete Online with Ottr
Ready to get started? Order online with Ottr and get fast delivery throughout Greater Boston. We take the guesswork out of sourcing crushed concrete — so you can focus on building with confidence.