Recycled crushed concrete vs quarried road base: cost and use

The comparison usually gets framed as recycled versus virgin, which is not really the decision anyone is making. The decision is between material you already have on the job and material you buy and truck in. That framing changes which differences matter. Here is how the two stack up on specification, consistency, cost and risk, and the cases where quarried material is still clearly the right answer.

On specification, Queensland already treats them together

The Department of Transport and Main Roads used to specify recycled pavement material separately from natural and quarried material, under MRTS35 Recycled Materials for Pavements. That separation is a large part of why recycled material saw limited use in Queensland unbound pavements: it had to be called up deliberately, and on most jobs it was not.

The NACOE research programme, run jointly by TMR and the Australian Road Research Board, addressed this through project P94, Optimising the Use of Unbound and Stabilised Recycled Pavement Materials in Queensland. Its laboratory work concluded that recycled materials show performance similar to natural and quarried materials, and on that basis TMR consolidated MRTS05 Unbound Pavements into a single specification covering natural, quarried and recycled material. Type 2, one of the types used for base and sub-base, is stated in the specification as able to be produced from natural, quarried or recycled material.

So the specification does not draw the line where people expect. It draws it at whether the material meets the nominated requirements, not at where it came from. The exception is worth naming: Types 1 and 3 tie the coarse component to a certified quarry source, and no amount of testing on recycled material changes that requirement.

The comparison, line by line

Why the cost gap is wider than the per-tonne rates suggest

Comparing a per-tonne crushing rate against a per-tonne quarry rate understates the difference, because it counts one line item and ignores three. When you cart concrete off and buy base in, you pay to load it, you pay to move it, you pay the disposal charges at the other end including the Queensland waste levy, which for the 2026-27 financial year sits at $135 per tonne in the metropolitan Level 1 zone, and then you pay again to purchase and cart in the replacement product. Crushing on site collapses that into one movement of material that never leaves the job.

On-site crushing is priced per tonne and weighed on the machine's onboard belt scale, so you are billed on what actually came off the belt rather than an estimate. Most jobs land around $10 per tonne, and higher-tonnage jobs can come in as low as $8 per tonne. The saving that usually surprises people is not the crushing rate at all. It is the two sets of truck movements and the disposal charges that stop existing.

Where quarried material is still the right call

There is a real answer here and it is not always ours. Quarried material is the correct choice in several situations:

• The contract nominates a Type 1 or Type 3 material, where the specification requires the coarse component to come from a quarry holding current certification.
• The job needs a single, tightly controlled source with a long testing history behind it, which is easier to demonstrate from a quarry than from a one-off stockpile.
• The material on site is not clean. Concrete mixed with timber, plasterboard, soil or general rubbish has to be separated before it is worth crushing, and sometimes that is not economic.
• The tonnage is small. Below roughly 20 tonnes, mobilising a crusher cannot pay for itself, and buying base in is genuinely cheaper.
• There is no concrete on site to start with. Recycled material only competes on cost when the feed is already in front of you or is close by.

None of those are arguments against recycled material as a class. They are arguments about a particular job, which is the level the decision actually sits at.

The practical way to decide

Start with the contract. If a subtype is nominated, read which type it belongs to, because the type carries the source and certification requirements while the digit after the decimal point carries the minimum CBR. If a certified quarry source is required, the decision is made for you. If it is not, the question becomes an arithmetic one: how many tonnes of clean concrete are on site, how much base does the job need, and how far away is the nearest facility that would receive the one and sell you the other.

On a job with real tonnage and clean feed, the arithmetic usually favours crushing where the material already sits. On a small job, or one with contaminated feed, or one with a certified source called up, it does not. We will tell you which one yours is before you commit to either.

For the grades a crush produces and where each one gets used, see our recycled aggregate and road base range.

To put tonnes against your own job before comparing the two options, use the material calculator.

The recovery side of the operation, and what happens to material that does leave site, sits under material recycling.

Send through the tonnage, the material type and the site address for a firm per-tonne price, or call 0401 803 662. If buying quarried base is the cheaper answer for your job, we will say so.