Bitumen 70/100: EN 12591 Specification, Applications and Export Supply

The two numbers are the edges of a penetration band, not a brand and not a quality claim. Under EN 1426 a loaded needle is driven into a temperature-conditioned sample and the depth it reaches is reported in tenths of a millimetre; anything landing between 70 and 100 is a 70/100. Two features of that band matter commercially. It is 30 dmm wide — half again as wide as the 50/70 band and twice the width of the ASTM 85-100 band this grade is usually compared against — so “in grade” covers a far broader spread of real binders than most buyers assume, and it is worth knowing where in the band your cargo actually sits. And the measurement itself is procedurally identical under EN 1426, ASTM D5 and IS 1203: same needle geometry, same 100 g load, same 5 seconds at 25 °C. A penetration result from any of the three is directly comparable. Almost nothing else on an EN 12591 certificate has that property.

What separates 70/100 from a commercial designation such as 80/100 is not the needle test. It is the standard sitting behind it. EN 12591 is the European specification for paving grade bitumens, and it does far more than state a penetration band. It fixes a softening point window, it controls low-temperature brittleness through the Fraass breaking point, and it measures ageing with the rolling thin film oven test rather than the static thin film oven test used in the ASTM tradition. A cargo certified as EN 12591 70/100 has therefore been tested against a wider and, in places, a stricter set of properties than a cargo described as 80/100 on a general refinery data sheet — even when the two penetration results are identical.

Where 70/100 sits in the EN 12591 ladder

European paving grades are named for their penetration band and run from hard to soft. Penetration and hardness move in opposite directions, so a higher number is a softer binder:

• 20/30 and 30/45 — hard grades. High-modulus asphalt, heavily loaded base layers and industrial applications.
• 35/50 and 40/60 — stiff paving grades used in warmer Southern European conditions and on heavily trafficked routes.
• 50/70 — the mainstream European paving grade and the direct commercial neighbour of 70/100. Most Southern and Western European hot mix is built on it.
• 70/100 — the soft mainstream grade. Cool and temperate paving, lower traffic categories, binder and base courses in cold regions, thin surfacing, and the usual base binder for emulsions and polymer modification.
• 100/150 and 160/220 — very soft grades for Nordic and high-latitude paving, cold-region surface treatments and cold-applied work.
• 250/330 — the softest listed paving grade, used at the cold extreme and in specialised applications.

Why 70/100 exists as a designation of its own

Buyers who work mainly in ASTM markets often ask why the trade needs a 70/100 at all when 80/100 already covers the same territory. The answer is that the two bands were drawn by different committees for different purposes. The ASTM and AASHTO soft paving grade is 85-100, with 80/100 as the commercial designation printed on most Middle East, South Asian and CIS data sheets. EN 12591 draws the same part of the scale as 70/100, opening the band 10 to 15 dmm lower at the bottom.

That wider floor is deliberate. It lets a European refinery deliver a binder that is genuinely soft in winter service without forcing every batch above 80 dmm, and it lines up with the Fraass and RTFOT limits that accompany it. The practical consequence for a buyer is one you should plan around rather than argue about: an in-grade 80/100 cargo always falls inside the 70/100 penetration band, but the reverse is not true, and penetration alone was never what made a cargo EN 12591 compliant.

Which markets buy this grade

The obvious home for 70/100 is Europe itself — Northern, Central and Eastern European road programmes, where national road authority documents and the national annexes to the EN asphalt standards routinely list it among the permitted paving grades for binder courses, base courses and lower traffic categories. Beyond the EU, the grade travels wherever the European standards travelled: the Western Balkans, Turkey, the Caucasus and parts of Central Asia, the francophone North and West African markets that specify to EN rather than ASTM, and a growing number of tender documents in the Gulf and South Asia written by European consulting engineers. When a specification arrives quoting EN 1426 and EN 1427 rather than ASTM D5 and D36, this is usually the grade being asked for.

Penetration and softening point

These two define the grade and they are the first figures an engineer checks. The 70/100 band is wide, spanning 30 dmm, and where a batch sits inside it matters. A cargo at 74 dmm and a cargo at 96 dmm are both fully in grade and they are not the same binder in a mix: the first behaves close to a stiff soft grade, the second close to a 100/150. Ask for the measured value on the Certificate of Analysis rather than accepting the range, particularly if your mix design was developed around a specific binder viscosity.

The softening point window of 43 to 51 °C also works as an internal cross-check. Softer binders sit lower on the ring and ball scale, so a certificate reporting 95 dmm penetration alongside a 50 °C softening point is internally inconsistent and should be queried. That pairing usually means either a laboratory error or two different streams sitting in the same tank.

Fraass breaking point — the line ASTM grades do not carry

Of everything on this specification, EN 12593 is the line most likely to decide whether a cargo is fit for the market it is being sent to. The apparatus cools a bitumen film on a flexible steel plaque and bends it repeatedly as the temperature falls; the reported figure is the temperature at which the film first cracks. Because the requirement is a maximum, a more negative result is the better result, and the 70/100 limit of -10 °C sits two degrees below the -8 °C that applies to 50/70. Two degrees looks trivial written down. Across a continental winter it is the margin between a binder that still relieves contraction stress and one that has stopped.

It is worth knowing the test’s limits as well as its value. Fraass is an empirical index run on a thin film rather than a fundamental rheological measurement, and reproducibility between laboratories is modest — a result of -11 °C from one laboratory and -9 °C from another on the same drum is not evidence of fraud. The modern instrument aimed at the same question is the bending beam rheometer used in performance grading. But Fraass is what EN 12591 names, and it is what a European engineer will look for on the certificate.

This is a direct measure of the failure mode that actually ends the life of a pavement in a cold climate. Thermal cracking is what happens when a binder becomes brittle faster than the pavement can relieve the contraction stress building up inside it, and no amount of penetration or softening point data predicts it, because both are measured at or above 25 °C. If you are buying for a market with hard frosts, this is the line to insist on. If your supplier’s certificate omits it, treat that as a gap in the certification rather than an oversight, and be aware that it is the line most often dropped when a nominally equivalent cargo is offered against an EN specification.

RTFOT: change of mass, retained penetration and softening point after hardening

EN 12591 assesses ageing with the rolling thin film oven test, EN 12607-1, in which the binder is rotated in glass bottles in a hot air stream at 163 °C. The ASTM tradition uses the static thin film oven test, ASTM D1754, in which the binder sits still in a pan. The rolling method continually renews the surface of the film, so it is generally regarded as the better simulation of what happens to a binder passing through a mixing plant, and the two tests do not produce interchangeable results. If a project specification says EN 12591, an ASTM D1754 result on the certificate does not satisfy it.

Three numbers come out of the test. Change of mass is capped at ± 0.8 % for 70/100 — note the plus-or-minus, because a binder can gain mass by taking up oxygen as well as lose it by driving off volatiles, and the standard limits movement in either direction. That allowance is wider than the ± 0.5 % applied to 50/70, which is normal: a softer binder carries more of the lighter fractions that leave first. Retained penetration, a minimum of 46 %, is the one to do arithmetic on: a binder arriving at 90 dmm must still measure at least about 41 dmm after ageing. Softening point after hardening, a minimum of 45 °C, sets a floor on the stiffness the binder will have in the finished road rather than in the tank.

Note the direction of that last requirement. On the unaged binder the softening point has a ceiling of 51 °C; on the aged residue it has a floor of 45 °C. EN 12591 is asking the binder to be soft on arrival and still competent after the plant has worked on it. A soft grade that ages hard defeats the entire reason for buying it — you pay for winter flexibility and lay a binder that has already lost it on the day the road opens.

Flash point and solubility

EN 12591 sets a flash point minimum of 230 °C for 70/100, determined by Cleveland open cup to EN ISO 2592 (published for years as EN ISO 2592, and you will still see that reference on older certificates). It is the number your terminal operator, your insurer and the destination Safety Data Sheet work from, and it is a floor on the certified value rather than a working temperature — the operating ceiling on this grade is set far lower, by oxidation, at around 180 to 185 °C. Do not read the flash point as a point of difference between the standards: ASTM D946 grade 85-100 requires a minimum of 232 °C, marginally above the EN figure, while many regional commercial 80/100 data sheets print 225 °C. The three numbers sit within seven degrees of each other and none of them changes how the binder should be handled. Build your safety case on the measured value on your own Certificate of Analysis, not on a specification minimum from any of them.

Solubility at a minimum of 99.0 % to EN 12592 confirms the material is genuine bitumen rather than bitumen cut with filler or an extender. Note the solvent: EN 12592 uses toluene, while ASTM D2042 uses trichloroethylene. The pass criterion is the same in practice but the certificate should name the method it used. On soft grades this line matters more than on hard ones, because penetration is the cheapest property to manipulate — blending a heavy oil stream into a harder residue will push a needle test up into the 70/100 band while leaving material that fails solubility, loses excessive mass on the RTFOT and behaves nothing like paving bitumen in a mix.

What EN 12591 deliberately leaves out

There is no ductility requirement in EN 12591. Buyers moving across from ASTM specifications often expect one and read its absence as an incomplete certificate; it is not. The European standard treats the RTFOT pair and the Fraass point as more informative measures of the same underlying concerns, and it applies a separate group of properties — the Fraass breaking point itself, kinematic viscosity at 135 °C to EN 12595, and the calculated penetration index among them — according to national circumstances rather than universally. If your project calls up one of those, name it and its limit in the enquiry, because none of them appears on a default certificate and none can be added retrospectively to a cargo that has already been produced.

The trade-off in one sentence

Every step up the penetration scale buys low-temperature flexibility and pays for it with high-temperature stiffness. Bitumen 70/100 resists thermal cracking better than 50/70 and ruts more readily under the same axle load at the same pavement temperature. No unmodified paving grade does both well — that gap is precisely why EN 14023 polymer modified binders exist.

When 70/100 is the right call

• Cold and cool-temperate climates — where winter minimum pavement temperatures, not summer maxima, are what end the pavement’s service life. The Fraass limit of -10 °C is the technical expression of that choice.
• Lower traffic categories — regional, rural, distributor and residential roads where axle loading is light to moderate and durability and workability matter more than rut resistance.
• Binder and base courses in cold regions — layers set well below the surface run cooler in summer and colder in winter than the wearing course, and a softer binder there resists the cracking that propagates upward through the pavement.
• Thin surfacings and overlays — a thin layer loses heat to the underlying pavement quickly, and a softer binder gives the rolling crew a materially longer compaction window on a cold day.
• Highland and mountain alignments — altitude keeps pavement temperatures down even in a warm country, and it is normal for a road authority to specify a softer grade for the high sections of a route than for the lowland ones.
• Surface dressing and sprayed seals in cool weather — the binder must wet the chippings and hold them through the first winter, and a softer grade does that at a lower spray temperature.
• Base binder for emulsion and for polymer modification — both processes stiffen the binder, so starting from 70/100 leaves a residue or a modified product that is still flexible in cold service.

When to move to 50/70 instead

Specify the harder grade where summer pavement surface temperatures run high for a long season, where traffic is heavy and channelised, and above all at the locations where load is applied slowly and repeatedly: junction approaches, signalised intersections, bus stops and bus lanes, climbing lanes, roundabout circulatory carriageways, weighbridge queues, container yards and port access roads. Rutting appears at those points first, and the binder will be blamed for it whether or not it was the deciding factor. In Southern Europe, in the Mediterranean basin and in Gulf or South Asian projects written to EN standards, 50/70 is the default and 70/100 is the exception that needs justifying.

Use both on the same job where the job needs both

Specifying one grade for the wearing course and a different one for the layers beneath is normal European practice, not a compromise. A stiffer binder near the surface resists rutting where the wheel load is concentrated; a softer binder in the base resists the cracking that starts at the bottom of the bound layers and works upward. The same logic applies along a route that climbs from a hot coastal plain into cold uplands: two grades on one contract is a cleaner answer than forcing a single grade to cover a temperature range it cannot.

Ask the road authority, not only the climate map

In most European markets the choice is at least partly made for you. National road authority specifications and the national annexes to the EN asphalt product standards set out which paving grades are permitted for which mixture type and which traffic category, and a technically sound proposal that is not on that list will still be rejected. Before you fix the grade in a purchase contract, confirm what the governing document permits — this is the single most common reason a correctly specified cargo turns out to be unusable on arrival.

When a penetration grade cannot answer the question

A penetration number is one measurement at one temperature. It says nothing about how quickly the binder stiffens as it cools or softens as it heats, and nothing about the specific temperature range the pavement will experience. Where a site combines hot summers with hard frosts, the honest answer is not a compromise penetration grade. It is either a polymer modified binder to EN 14023, or rheological testing of the actual binder — dynamic shear and bending beam measurements of the kind used for performance grading — so that the decision rests on the temperature range the road has to survive rather than on a single needle test at 25 °C.

Certifying a cargo as EN 12591 70/100

Ask for the Certificate of Analysis to state the EN method reference against each line — EN 1426 for penetration, EN 1427 for softening point, EN 12607-1 for the hardening test, EN 12592 for solubility, EN ISO 2592 for flash point and EN 12593 for Fraass. A certificate that reports the right numbers under ASTM method references has not demonstrated EN conformity, and an engineer working to a European specification is entitled to reject it. This is the most common documentary failure on this grade, and it is entirely avoidable if the requirement is written into the contract rather than raised after the cargo has sailed.

The second thing to fix early is the Fraass breaking point. Because it sits in the group of EN 12591 properties applied according to national circumstances, it is frequently absent from a default certificate. If your destination has cold winters, name it explicitly in the enquiry as a required certificate line, along with the limit you need it tested against.

Placing the product on the European market

Paving grade bitumen sold into the European Union is a construction product, and EN 12591 is the harmonised standard that underpins CE marking and the accompanying Declaration of Performance under Regulation (EU) 305/2011. Two points are worth settling before contracting. First, establish who issues the Declaration of Performance for the cargo you are buying and against which factory production control arrangement, because the DoP travels with the product and your customer will ask for it. Second, understand that an importer who places a cargo on the EU market under its own name and address takes on the obligations of a manufacturer under that Regulation. Neither point is a reason to avoid the trade, but both are reasons to take your own compliance advice before you sign rather than after the container is on the water.

Packing options and typical container loading

Loading figures follow the packaging, not the grade, so they are the same as for any paving bitumen: about 12 MT as eighty 150 kg drums in a 20-foot container, about 14.4 MT as eighty 180 kg drums, around 20 MT as twenty 1 MT jumbo or meltable poly bags, 20 to 25 MT in a bitutainer or tank container, and parcel quantities in bulk for terminals with tank farms. Actual counts move with drum dimensions, container type and the gross or axle weight ceiling on the road at destination.

Which of those options is right, however, is a question the grade does influence, because most 70/100 goes to cold destinations and a soft binder behaves differently in the yard:

• New steel drums remain the default where the receiving plant has no bulk facility, but stack height needs agreeing before the container is loaded rather than argued about after it opens.
• Meltable poly bags earn their premium at a cold destination, because the whole unit goes into the melter without decanting and without a drum to strip, cool and dispose of in freezing conditions.
• Bitutainers and bulk parcels are the least damaging route for the binder itself: product that never cools is product that never has to be reheated, and every reheat cycle costs a soft grade some of the penetration you bought it for.

Two contract points apply whichever route you take. Write new drums into the specification — reconditioned drums are cheaper and are the single most common origin of contamination claims at discharge — and confirm in writing that drum tare is excluded from the invoiced net weight. Fuller detail is on the packaging and logistics and shipping pages.

Storing a soft grade, and a note on cold destinations

Two opposite problems affect this grade in the yard. In hot ambient conditions and direct sun, drums of a soft binder deform under stack load more readily than drums of 50/70, and bagged product consolidates. Nothing about that damages the binder chemically, but it slows discharge and produces arguments about damaged cargo that are really arguments about storage. Agree the number of stack tiers before the container is loaded, store under cover, keep drums upright and clear of standing water, and plan to move a soft grade rather than hold it through a hot season.

At the cold end, the risk is the opposite. Drummed bitumen arriving into a genuinely cold destination takes far longer to bring up to discharge temperature than most first-time importers budget for, and impatience at that point is what produces localised overheating and a scorched batch. Where the destination is a cold-climate market — which, for this grade, it frequently is — make sure the receiving plant has adequate and correctly sized melting capacity before the cargo is nominated.

Documents and sampling

An EN purchase differs from an ASTM one in exactly two places on the document list — the Certificate of Analysis has to be written against EN methods, and an EU destination adds a Declaration of Performance. Everything else is the ordinary export file.

• Certificate of Analysis — batch specific, with measured results reported line by line against the EN method that produced them. Two failure patterns recur on this grade: specification limits copied down the page in place of results, and the Fraass and RTFOT lines quietly missing.
• Declaration of Performance — for cargo placed on the EU or EEA market, issued against the producing plant’s factory production control arrangement. It attaches to the plant and cannot be added by a trading house afterwards, so establish it before contracting.
• Technical Data Sheet and Safety Data Sheet — the general product specification and handling guidance, plus the safety document your terminal will demand and destination customs increasingly ask to see.
• Certificate of Origin — issued by the chamber of commerce, driven by duty treatment at destination rather than by anything technical.
• Independent inspection report — quality, quantity and packing condition at the load port, from an inspection company acceptable to both sides. Write the laboratory scope into the inspection instruction: a default scope covers penetration and softening point and will skip Fraass and RTFOT, which are the two lines you are actually paying to have verified.
• Commercial set — invoice, packing list and bill of lading.

Sampling deserves more care on a band 30 dmm wide than on a narrow one. Where the cargo sits inside the band changes how it behaves in a mix, so require penetration and softening point to be reported as measured figures rather than as a pass against the range, and require the sample to be drawn across the load rather than from whichever drum stands nearest the container door. Retained samples should be sealed at loading and held by both parties — without that chain of custody, a disputed result at destination is an argument neither side can win. The Certificate of Analysis guide and the test methods reference set out what each line should look like.