A contractor wins a council car park resurfacing job. The asphalt is ordered, the crew is booked, and the first load arrives forty minutes later than planned because the plant was running behind on a highway job. The second load arrives twenty minutes after the first. The paver empties between trucks twice before lunch.

The finished surface has two transverse joints that were not on the drawing, a cold spot where the paver stood, and density results that come back marginal in three of eight lots. None of that was a workmanship failure at the roller. It was a supply and logistics failure that the roller could not fix.

This guide is about asphalt as a material and a process. How to write the tender response for a road job is covered in our guide to road construction and resurfacing tenders; sprayed seals are a different surfacing family entirely and are covered in sprayed sealing and bituminous surfacing.

The material with a clock on it

Concrete has a clock too, but asphalt’s is harsher because the constraint is thermal and it runs in both directions.

• Too hot and the mix is damaged at the plant, and the binder is degraded before it ever reaches the road.
• Too cold and it cannot be compacted. Density is achieved in a temperature window, and once the mat drops below it no amount of rolling will recover it.
• The window shrinks with thin layers, cold ground and wind. A thin correction course on a windy winter morning may have only minutes.
• Everything upstream eats the window. Time at the plant, haul time, queueing on site, and any pause in laydown.

That single fact reorders the priorities. Continuity of supply matters more than the unit rate, because a cheaper tonne that arrives irregularly produces a surface you may have to replace. It is the reverse of how most materials are bought.

The mixes you will actually meet

Mix nomenclature differs between road authorities and that is a frequent source of ordering errors. The families, however, are consistent.

Family	What it is for	Watch for
Dense graded asphalt	The general-purpose workhorse: wearing courses, intermediate courses, car parks, local roads	Nominal size must suit layer thickness; too large a size in too thin a layer will not compact
Open graded asphalt	Surface drainage and noise reduction on higher-speed roads	Specialist; sensitive to temperature and to contamination, and not a patching material
Stone mastic asphalt	Heavily trafficked surfaces needing deformation resistance	Needs a modified binder and tight process control; expensive to get wrong
Fine gap graded / corrector mixes	Regulating courses and shape correction before a wearing course	Thickness varies by definition, which complicates both ordering and measurement
Cold mix and patching products	Temporary and maintenance patching	A maintenance product, not a substitute for hot mix in new work

Three ordering details cause most of the errors: nominal aggregate size against layer thickness, binder class (including whether a polymer-modified binder is specified), and whether the specification nominates a registered or approved mix for that road authority. On authority work the mix is usually drawn from an approved register, and substituting an equivalent is a conformance question rather than a commercial one.

The plant, and why availability decides your programme

Asphalt comes from a fixed plant with finite output, a production schedule and a service radius. For a civil SME that creates constraints no purchase order can overcome.

• You are competing for the plant’s day. Large jobs get priority, and a council car park will be fitted around a highway resurfacing run.
• Mix changeovers cost the plant time, so an unusual mix in a small quantity may be scheduled awkwardly, or attract a minimum tonnage.
• Plants shut down. Seasonally in cooler regions, for maintenance, and on public holidays. In many regional areas there is exactly one plant within economic haul distance.
• Night and early starts are often the only slot for a small job, which brings its own traffic, noise and fatigue consequences.
• Supply can be withdrawn. If the plant’s own paving crew needs the output, a third-party order is the first thing to move.

The practical consequence at tender stage is to confirm plant availability and the likely slot before you commit to a programme, and to say in the tender what you have assumed. A programme that depends on a plant nobody has spoken to is a programme with an unpriced risk in it — see our guide to writing a construction program for tenders.

Buying asphalt: the commercial structure

Asphalt can be bought three ways, and the choice changes who carries which risk.

Arrangement	You provide	Risk you carry
Supply only, ex plant	Cartage, paving crew, rollers, traffic	Everything after the plant gate, including haul time and temperature
Supply and delivery	Paving crew, rollers, traffic	Laydown and compaction; delivery timing is contractual but rarely guaranteed
Supply and lay (sublet)	Preparation, traffic, programme and interface	The surface still has to conform, and the substrate is yours

Most civil SMEs use the third for anything substantial, and the questions to settle are the same ones any sublet package needs — see engaging and managing subcontractors. The asphalt-specific additions:

• Who owns conformance? If density fails, who pays to remove and replace — and does that change if the substrate was out of tolerance?
• What is the minimum tonnage, and what is the standing charge if the crew arrives and cannot start?
• Who pays for a load rejected on temperature, and who decides?
• What happens if the plant cannot supply on the day — rebooking, standby, or your cost?
• Is price firm, and for how long? Bitumen is a refined product with its own price movement; a long job without a mechanism is an exposure — see rise and fall and cost escalation.
• Is cartage inside the rate? On a delivered rate the haul is a function of distance from the plant, which the supplier controls and you do not — the same structural point our guide to materials supply agreements makes about quarry product.

Haul time, temperature and the distance problem

Haul time is the variable that quietly decides whether a regional job is viable.

• Heat loss is driven by time, surface area and conditions. A thin spread in an uncovered truck on a cold windy day loses heat far faster than a full load in a tarped, insulated body.
• Tarping is not optional. It is the cheapest temperature control available and it is routinely skipped on short hauls.
• Specifications commonly limit delivery temperature, haul time or both. Where they do, that limit sets your maximum economic haul radius, not your truck’s range.
• Queueing on site is haul time. A truck waiting at the gate is losing heat exactly as if it were still driving.
• Warm mix technologies change the arithmetic by allowing production and compaction at lower temperatures, which can extend haul distance and the paving season. Whether they are permitted is a specification question.
• Insulated and heated bodies buy time, and on marginal hauls they are the difference between conforming and not.

At tender stage, measure the actual road distance from the nominated plant and estimate the real cycle time, including loading, traffic and site turnaround. A job that works at forty minutes may not work at seventy, and that is a go/no-go input rather than a detail — see the go/no-go decision.

What has to be right before the paver arrives

Asphalt is unforgiving of what is underneath it, and once the mat is down the substrate is no longer inspectable.

• The surface must be sound, clean and dry. Dust, mud tracked from a haul road, or standing water in a low spot will all cause a bond failure that appears months later.
• Shape and level must already be correct. A paver follows what it is given; it does not correct shape. Correction is a separate regulating course, priced and programmed as one.
• The tack coat decides the bond. Correct rate, broken before paving, and not tracked away by site traffic. Too much is as bad as too little.
• Edges, ironwork and services must be set. Pits, valve boxes and covers adjusted to final level before paving, because cutting them in afterwards means breaking the new surface.
• The underlying pavement must be conforming. Compacting asphalt over a soft or wet subgrade produces deformation no surfacing can fix — see pavement stabilisation, testing and conformance.
• Access and turning space for trucks is a real constraint on a constrained site, and it should be walked before the day.

Most of this is hold-point territory, and it belongs in the inspection and test plan with a release before the first load is ordered — see quality management plans and ITPs.

Laydown: paver speed, feed and the stop that shows

The objective in laydown is a constant, uninterrupted mat. Almost every visible defect comes from a departure from that.

• Match paver speed to supply, not the other way round. A paver running faster than the trucks can feed it will stop, and every stop leaves a mark.
• Keep the hopper partly full. Running it empty between trucks causes segregation, where coarse aggregate separates and produces a patchy, open texture.
• Avoid handling the mix more than necessary. Every transfer is an opportunity for segregation and heat loss; shovelling material around behind the paver generally makes the surface worse, not better.
• Set the screed properly and let it work. Initial compaction comes from the screed; constant adjustment chases a problem that is usually upstream.
• Plan the run sequence before the first truck. Where the joints will fall, which lane first, how traffic is kept off, and where the paver can be emptied if supply fails.
• Have a plan for a failed load. Somewhere to put it, and a decision-maker who will reject rather than lay marginal material.

Compaction, and the window you cannot extend

Density is what the specification pays for and what determines how long the surface lasts. It is achieved in a temperature window that opens when the mat is placed and closes as it cools.

• Establish a roller pattern and stick to it. Number of passes, sequence and roller type, proven at the start of the job and then repeated.
• Enough rollers for the paver’s output. One roller behind a fast paver on a cool day will not achieve density, and that is an arithmetic problem to solve before the day.
• Stay close to the paver. The breakdown roller works in the hottest part of the window; falling behind loses the window permanently.
• Thin layers cool fastest, so correction courses and thin wearing courses are the hardest to compact and the most often marginal.
• Do not stop a roller on a hot mat, and watch for over-rolling once the mix has cooled, which can crack the surface rather than densify it.
• Edges need deliberate attention, because unsupported edges compact differently and are where failures start.

Intelligent compaction and temperature monitoring systems are increasingly available and give a continuous record rather than a spot check, which is useful evidence as well as a control — related to the delivery data discussed in our guide to machine control and GNSS.

Joints, the part that is inspected first

Joints are where asphalt fails, and they are the first thing any experienced inspector looks at.

• Longitudinal joints between adjacent runs are best avoided by paving in echelon where width and traffic allow. Where they cannot be avoided, the joint is a planned detail, not an accident of where the paver stopped.
• Keep joints out of the wheel path where the specification allows, and align them with lane lines.
• Transverse joints come from stopping, which is why supply continuity matters. Where one is unavoidable it is cut back to full depth on sound material and tacked.
• Tack the vertical face. An untacked joint is a water path into the pavement and the beginning of a failure.
• Joints against existing work, kerbs and ironwork need the same treatment, and these are the ones most often skipped.
• Do not leave an unsupported edge open to traffic overnight without a temporary taper.

Weather, season and the day you should not pave

Specifications set weather limits for asphalt, and they are among the few limits in civil work that genuinely cannot be negotiated on the day.

• Rain stops it. Paving onto a wet surface destroys the bond, and rain on a hot mat ruins it. There is no partial version of this.
• Cold ground matters as much as air temperature. A cold pavement draws heat from the mat immediately, which is why early winter mornings are worse than the thermometer suggests.
• Wind accelerates cooling disproportionately on thin layers.
• Seasonal restrictions exist in cooler regions and on some authority specifications, and they can close the paving season entirely for certain products.
• Build the decision into the programme. A float allowance for weather on asphalt work is realistic planning, not padding — and the delay consequences are covered in our guide to extension of time and delay claims.
• Have a cancellation protocol with the plant, including the cut-off time and who pays for a cancelled run.

The hardest version of this is the marginal morning with a crew, a plant booking, traffic management in place and a client waiting. Decide in advance who makes that call and on what criteria, because a decision made under that pressure without a rule tends to go the wrong way.

Testing, conformance and what a low result costs

Asphalt conformance is assessed on the material and on the finished mat, and the consequences of failure are more severe than for most civil products because remediation usually means removal.

Checked	Typically by	If it fails
Mix properties and binder content	Plant production testing and sampling	Supplier issue, but your surface
Delivery temperature	Measured on arrival, recorded on the docket	Reject the load — far cheaper than laying it
Thickness and level	Survey and cores	Correction course, or removal where it affects levels at kerbs and ironwork
Density	Cores or nuclear gauge, by lot	Reduced payment or removal and replacement, depending on the specification
Surface shape and ride	Straightedge or profilometer on higher-order roads	Grinding, correction or replacement
Texture and joint quality	Visual and measured	Rework of the joint, which means cutting into new work

Two things worth building into the way you work. Record delivery temperature on every docket — it is a two-second habit that settles a dispute about a marginal lot months later, and it is exactly the kind of record our guide to dockets and daily records describes. And understand the lot definition before you start, because how the work is divided into lots determines how much has to come out when one fails.

Recycled content and where it is heading

Reclaimed asphalt pavement — the material milled off a road before resurfacing — is routinely reincorporated into new mix, and recycled content requirements are increasingly written into specifications and tender evaluation.

• Permitted proportions are set by the specification and vary by layer and by road authority. Higher proportions are permitted in lower layers than in wearing courses.
• Milled material has value. Where you are removing the existing surface, where that material goes and who gets the credit for it is a commercial term, not a disposal detail.
• Other recycled streams appear in specifications — crumb rubber, glass and plastics among them — usually through an approved mix rather than at your discretion.
• It is scored. Recycled content and embodied carbon now appear in evaluation criteria on larger work — see embodied carbon and decarbonisation and sustainability and IS ratings.
• Never substitute unilaterally. A mix containing recycled material that was not approved is a non-conformance regardless of how well it performs.

Pricing asphalt work honestly

Element	Note
Material, by tonne	Confirm whether the rate is ex plant or delivered, and for how long it holds
Wastage and over-run	Thickness tolerance means you buy more tonnes than the theoretical area × depth
Cartage	A function of distance and cycle time, and subject to its own obligations where sublet — see the road transport contractual chain order
Paving crew and plant	Usually a day rate; a short day costs nearly as much as a full one
Rollers	Enough for the output, not the minimum that fits the budget
Preparation	Milling, sweeping, tack, ironwork adjustment — frequently under-priced
Traffic management	Often the largest single line on an urban resurfacing job — see our traffic management plan guide
Testing	Sampling, coring and reinstatement of core holes
Standby and abortive costs	Weather cancellation, plant failure, a run that cannot start
Risk	The allowance for a lot that has to come out, which almost nobody carries

The commonest pricing error is treating a small asphalt quantity as a proportional share of a large one. Below a certain tonnage the fixed costs dominate completely — mobilisation, minimum loads, crew day rate and traffic management do not scale down — which is why small patching and car park jobs look expensive per tonne and genuinely are.

Checklist

• Is the specified mix an approved mix for this road authority, and have you ordered it by the right designation?
• Does the nominal aggregate size suit the layer thickness?
• Is a modified binder specified, and is it available from your plant?
• Have you confirmed plant availability and the likely slot for your dates?
• Is there a minimum tonnage or changeover charge?
• What is the real cycle time from the plant, including loading and site turnaround?
• Are trucks tarped, and is there a delivery temperature limit in the specification?
• Is delivery temperature recorded on every docket?
• Is the substrate conforming, clean, dry and correctly shaped before any order is placed?
• Is the tack coat rate specified, applied and broken before paving?
• Is ironwork adjusted to final level before paving?
• Is the joint layout planned, and are joints out of the wheel path?
• Have you enough rollers for the paver’s output, and an established roller pattern?
• Who decides to reject a load, and where does a rejected load go?
• Who decides to cancel for weather, by when, and who pays?
• Do you know the lot definition and what a failed lot costs?
• Is recycled content specified, and is the mix approved for it?
• Does the price hold, and is there an escalation mechanism on a long job?

The short version

• Asphalt is a time-and-temperature problem. Continuity of supply matters more than the unit rate, which inverts how most materials are bought.
• Nominal size against layer thickness, binder class, and whether the mix is on the authority’s approved register are the three ordering details that cause most errors.
• You are competing for the plant’s day. Confirm availability before committing to a programme, and say what you assumed.
• Haul time sets the economic radius, not the truck’s range. Queueing on site is haul time. Tarp everything.
• The paver does not correct shape. Correction is a separate course, priced and programmed.
• Tack coat decides the bond. Ironwork is set before paving, not cut in afterwards.
• Match paver speed to supply and keep the hopper partly full. Every stop leaves a mark and every empty hopper segregates.
• Density is won in a closing temperature window. Enough rollers, an established pattern, and stay close to the paver.
• Joints are inspected first and are where asphalt fails. Plan them, keep them out of the wheel path, and tack the vertical face.
• Weather limits are not negotiable on the day. Decide in advance who cancels and on what criteria.
• Record delivery temperature on every docket. It settles marginal-lot disputes months later.
• Understand the lot definition before starting, because it determines how much comes out when one fails.
• Below a certain tonnage the fixed costs dominate entirely, which is why small asphalt jobs are genuinely expensive per tonne.

Sources and further reading

This guide is general information for Australian civil construction businesses and is not engineering or materials advice. Mix designations, approved mix registers, binder classes, permitted recycled content, delivery temperature and haul time limits, weather and seasonal restrictions, lot sizes, testing frequencies and conformance and payment-reduction regimes are set by the project specification and by each road authority, and they differ materially between jurisdictions and between road classes. This guide deliberately does not reproduce temperatures, tolerances, thicknesses or test frequencies: take those from the governing specification. Always work from the project specification, the approved mix design and current advice from the supplier and a pavement engineer. Information is current as at October 2026.

• Australian road authority specifications and Austroads guidance for asphalt materials, production, transport, placement and compaction, which govern the mix families described in §02, the delivery and temperature requirements in §05, the preparation and tack coat requirements in §06, the compaction and joint requirements in §08 and §09, and the testing and conformance regimes in §11. These are issued separately by each state road authority and adopted with amendments by councils; the governing document is the specification for the particular contract.
• Australian Standards for the sampling and testing of asphalt and bituminous materials, referenced in §11, together with the requirements for NATA-registered laboratory testing applied by most authority specifications. The conformance and inspection framework these sit within is sourced in full in our guide to quality management plans and ITPs.
• Recycled content requirements referenced in §12, including reclaimed asphalt pavement proportions permitted by layer and the inclusion of other recycled streams through approved mixes. These are set by road authority specification and by sustainability policies that differ by jurisdiction and are revised frequently. Sourced in full in our guides to embodied carbon and decarbonisation and sustainability and IS ratings.
• Related TenderBuilt guides carrying the primary-source detail referenced above: road construction and resurfacing tenders, sprayed sealing and bituminous surfacing, pavement stabilisation, testing and conformance, materials supply agreements, and traffic management plans.