Bitumen vs Asphalt — What’s the Difference?

The bitumen vs asphalt question has two separate answers, and confusing them is why the argument never ends. Technically, asphalt is made from bitumen — bitumen is the black binder, asphalt is the finished mix of that binder with aggregate. One is an ingredient of the other, not a rival to it. Regionally, American English calls the binder itself “asphalt”, so a US engineer saying asphalt often means exactly what a British engineer calls bitumen. Both usages are correct in their own market. Neither is a mistake. But on a purchase order, the ambiguity costs money.

This guide settles the bitumen vs asphalt question properly: the technical relationship between the two, why the terminology diverged between Britain and America, where tar fits and why it disappeared, how the materials differ in production, cost and testing, and what to write on a contract so both sides mean the same thing.

Bitumen vs asphalt: how the two relate

Strip out the regional vocabulary and the engineering answer is simple. Asphalt contains bitumen. They are not two competing products.

The last two rows are the practical heart of it. You can buy bitumen from another continent. You cannot buy asphalt from another continent. Asphalt mix leaves the plant at around 160 °C and has to be laid and compacted before it drops below roughly 100 °C, which puts a hard limit of an hour or two on haulage. That is why every asphalt plant serves a local radius, and why international suppliers like us ship binder rather than mix.

Why the terminology split: UK vs US English

This is the actual source of nearly every bitumen vs asphalt argument, and it is a vocabulary problem rather than a technical one.

Which markets use which

Bitumen is standard in the UK, Ireland, Australia, New Zealand, South Africa, India, the Gulf, most of Africa and most of Asia. If a tender is written in British-influenced English, bitumen means the binder.

Asphalt for the binder is standard in the United States and Canada, and in Latin American markets that follow US practice. The Asphalt Institute, the industry’s US body, uses “asphalt” throughout to mean the binder — which is why American technical literature reads oddly to a British engineer.

Some markets use their own words entirely. Brazil says CAP, from cimento asfáltico de petróleo. Spanish-speaking Latin America says asfalto. Francophone Africa says bitume. Our bitumen grade equivalence chart maps the grading systems these markets use against each other.

Where tar fits, and why it is gone

Tar is the third term in this confusion and the one where getting it wrong actually matters, because tar and bitumen are chemically different materials with very different health profiles.

Coal tar was widely used for road surfacing into the mid-twentieth century, which is where “tarmac” and “tarred road” come from. The word survived in everyday speech long after the material was replaced. When someone today says a road is “tarred”, they almost certainly mean it was surfaced with bitumen.

The health evidence changed practice. The International Agency for Research on Cancer classifies coal tar as carcinogenic to humans, while occupational exposure to bitumen sits in a lower, less certain category. Coal tar road use has been phased out across Europe, North America and most other regulated markets. Coal tar pitch still has industrial applications — aluminium smelting anodes, some roofing products — but not paving.

If a specification you have been sent names tar for a road surface, it is almost certainly an outdated document. Query it before pricing.

Types of asphalt mix

Once you know asphalt is the mix rather than the binder, the next question is which mix. These are the categories a contractor chooses between, and each needs a different binder from us.

How bitumen is made, and how asphalt is made from it

Bitumen production

Crude oil goes through atmospheric distillation, which takes off the light fractions — gases, naphtha, kerosene, gas oil. The heavy residue then goes to a vacuum distillation unit, where reduced pressure allows further separation without cracking the molecules. What comes off the bottom is bitumen.

From there, the grade is set by how it is finished. Straight-run material is blended to a target penetration or viscosity. Oxidized grades are made by blowing air through hot bitumen, which raises the softening point and hardens the product for industrial and waterproofing use. Polymer modified grades have SBS or other polymers blended in under high shear.

Not all crude produces good bitumen. Naphthenic and heavy sour crudes give better yields and better binder properties than light sweet crudes. This is why bitumen availability is tied to which refineries are running which crude slate, and why supply tightens when refiners shift to lighter feed.

Asphalt production

An asphalt plant heats and dries aggregate, then combines it with hot bitumen and mineral filler in proportions set by a mix design. The mix is discharged into insulated trucks and taken directly to the paving site, where it is spread by a paver and compacted by rollers while still hot.

The mix design is the engineering. Marshall or Superpave methods determine the gradation and the optimum binder content — typically 4.5 to 5.5 percent by weight. Too little binder and the mix ravels; too much and it rutts and bleeds. That percentage is why a single tonne of bitumen produces roughly twenty tonnes of finished asphalt.

Cost: why the two are not comparable

Buyers sometimes try to compare a bitumen price against an asphalt price and conclude one is far more expensive. They are measuring different things.

The relationship worth remembering: one tonne of bitumen makes roughly twenty tonnes of asphalt. So a rise of USD 100 per tonne in bitumen adds about USD 5 per tonne to the mix — small on the surface, but on a large paving programme it is a material figure, which is why contractors watch binder prices closely. Indicative levels are on our bitumen price page.

Testing: different materials, different tests

Another place the bitumen vs asphalt distinction becomes concrete. The two are tested for entirely different properties.

A certificate of analysis for bitumen shows the left-hand column. If a supplier hands you a document with Marshall stability figures on it, they are describing a mix, not a binder. Test methods are maintained by ASTM International and, in Europe, under the EN standards.

Natural asphalt: the third category

Both refined bitumen and manufactured asphalt are industrial products. There is also naturally occurring material, and it confuses the vocabulary further.

Note the HS codes differ. Natural and petroleum bitumen sit under separate headings, which matters for customs classification and duty. Gilsonite is not a substitute for paving bitumen — it is a hard, high-softening-point additive used to modify a binder or a compound, not to replace one.

What this means for your purchase order

Everything above reduces to a few practical rules for anyone buying across borders.

• Name the grade and the standard, not the material. “Bitumen 60/70 to EN 12591” leaves no room for interpretation. “Asphalt” alone does.
• Confirm whether the buyer wants binder or mix. An enquiry for “500 tonnes of asphalt” from a US buyer usually means binder. From a UK contractor it usually means mix — and mix cannot be shipped, so the enquiry needs redirecting before anyone wastes a week.
• Check the certificate matches the material. Penetration and softening point describe a binder. Marshall stability describes a mix.
• Watch the HS code. Petroleum bitumen is 2713.20; natural bitumen and gilsonite are 2714.90; emulsion and cutback are 2715.00. Misclassification is a clearance problem and sometimes a penalty. The full documentation picture is in our bitumen export documentation guide.
• If a tender says tar, query it. It is almost certainly an outdated document rather than a genuine requirement.

What ZUMRUT supplies

We supply the binder, not the finished mix — because mix cannot travel. Our range covers penetration grades to ASTM D946 and EN 12591, viscosity grades to IS 73, performance grades to AASHTO M320, AC grades to ASTM D3381, Australian class grades to AS 2008, oxidized grades for waterproofing and industry, emulsion, cutback, polymer modified binder, membrane and gilsonite.

Every shipment carries a batch certificate of analysis stating the lot number, the production date and each test with its measured result against the standard your contract names. Loading is from Jebel Ali, Mersin and Bandar Abbas on FOB, CFR or CIF terms, minimum 100 MT.

Frequently asked questions about bitumen vs asphalt

Reference sources

• US terminology and practice

  The Asphalt Institute publishes American industry guidance, using “asphalt” throughout for the binder.

• European practice

  Eurobitume covers European bitumen handling, health and safety guidance.

• Test methods

  Binder and mix test standards are maintained by ASTM International and under the EN series.

• Health classification

  Coal tar and bitumen exposure classifications are published by the International Agency for Research on Cancer.

Related technical guides

For cross-referencing between grading systems, see the bitumen grade equivalence chart. For how long binder stays on specification, see the bitumen shelf life and storage guide. For the paperwork side of an international shipment, see the bitumen export documentation guide. Country-level supply detail is in the global bitumen supply guide.