Bitumen, asphalt, tar: what’s the difference?
- Bitumen It is obtained during the distillation of crude oil. It is black, tough and sticky, and is used in roofing membranes, waterproofing, insulation and soundproofing mats, and as a binding agent in road construction.
- Asphalt is a mixture of bitumen and aggregate. So what sticks to machinery is mainly bitumen mixed with grit and sand.
- Tar It is derived from coal, not from crude oil. It contains carcinogenic polycyclic aromatic hydrocarbons (PAHs). It is no longer used in road construction, but can still be found in old road surfaces, roofing membranes and paints.
All three behave in a similar way when it comes to cleaning: they adhere strongly, soften when heated and can be dissolved using a suitable solvent. Particular care must be taken with materials containing tar.
Where bitumen and asphalt residues are produced
- Road construction: Road pavers (screed, auger, tamper), roller tyres and rubber wheels, lorry tipper bodies, hand tools
- Asphalt mixing plants: Mixers, silos, flaps, conveyor belts
- Industry: Manufacture of roofing membranes, waterproofing and insulation mats, tanks, pumps and pipework
- Vehicles and areas: Bitumen splashes on paintwork, floors, walls and façades
A comparison of the methods
| Method | Suitable for | Disadvantages |
|---|---|---|
| Mechanical (scrapers, spatulas, sanding) | thick layers on sturdy surfaces | time-consuming; may damage the surface |
| Dry ice blasting | Machinery, moulds, sensitive components | A blasting machine is required; it is noisy and works slowly on thick layers |
| Blasting with granules | sturdy surfaces, concrete, steel | Abrasive materials, dust and blasting media must be disposed of |
| Heat / Burning off | thick layers | fumes that are harmful to health and, in the case of tar, carcinogenic; risk of fire |
| Bitumen remover | Machinery, tools, vehicles, nooks and crannies | Contact time, effluent via oil separator |
The most suitable method depends on the surface, the thickness of the coating and the environment. For thick coatings, a combination of methods is often worthwhile: first remove the coating mechanically, then dissolve the remainder chemically.
Bitumen removers: What matters
Conventional bitumen removers and many workshop remedies are based on diesel, test petrol or aromatic hydrocarbons. These are often classified as flammable, harmful to health or hazardous to water.
According to the safety data sheet, Eco-Nova’s bitumen removers are not classified as hazardous. For many applications on machinery, vehicles and surfaces, for example, Bituclean Extra be suitable. It is applied undiluted using a pressure sprayer, takes effect immediately depending on the thickness of the coat, and is then rinsed off with water. The resulting emulsion can be discharged via a suitable oil separator. The information in the safety data sheet and local regulations on wastewater discharge are decisive.
During our consultation, we will work with you to determine which bitumen remover is best suited to your surface, layer thickness and requirements, usually with a free sample or an on-site demonstration.
Here’s how to do it
- Switch off the machine and leave it to cool down. Although warm residue is easier to scrape off, the cleaning solution will evaporate more quickly.
- Pre-clean thick layers mechanically.
- Spray on the bitumen remover and leave it to work, depending on the thickness of the layer.
- Remove any loosened residue using a brush, scraper or high-pressure cleaner.
- Rinse with water and discharge the wastewater via an oil separator.
Prevention: With a release agent, the tarmac doesn’t stick in the first place
Bitumen requires the least amount of work, as it does not stick in the first place. That is why pavers, rollers, troughs and tools used in asphalt construction are sprayed with a release agent before use. This forms a thin film to which hot asphalt does not stick. The machinery stays cleaner, and cleaning at the end of a shift is quicker.
From 2027 onwards, the choice of release agent will become more important. From 1 January 2027, the occupational exposure limit for vapours and aerosols from bitumen (1.5 mg/m³) will also apply to the laying of rolled asphalt. According to BG BAU, mineral oil-based release agents can significantly increase measured levels. Its sector-specific guidance therefore recommends using release agents free from mineral oil-based substances, applied sparingly. This also applies to diesel, which is still frequently used as a release agent on construction sites, as diesel is a mineral oil product. In laboratory tests carried out by TPA GmbH (IFA method, SMA 8 S, 150 °C), diesel resulted in a measured value of 543.5 mg/m³ – approximately five times that of the mix without a release agent (104.0 mg/m³). With Antistick ECO, the values ranged between 105.9 and 141.1 mg/m³, which is 74 to 80 % lower than with diesel (Diesel as a release agent: What laboratory measurements show). More on this: AGW bitumen from 2027: What asphalt contractors need to bear in mind regarding release agents.
Antistick ECO by Eco-Nova is based on plant-derived raw materials (rapeseed oil methyl ester):
- Not classified as hazardous according to the safety data sheet
- Not classified as a dangerous good under ADR
- Flash point above 150 °C
- for road pavers, roller drums and rubber-tyred rollers, lorry bodies and thermal bodies, hand tools, asphalt mixers, as well as moulds and formwork
- in a 200-litre drum or a 1,000-litre IBC, test quantity 10 or 20 litres
We will work with you to determine which variant is best suited to your machinery and mix. When switching over, you should first use up any remaining stock, flush the tank, pipes and nozzles, and then test a small quantity on your own machinery.
Release agents for asphalt construction – Enquire about a quote or a sample quantity (10–20 litres).
More on cleaning pavers, rollers and lorries: Removing and cleaning asphalt on construction machinery
Always follow the instructions in the safety data sheet and wear the prescribed personal protective equipment. The safety data sheet is available on request to existing customers and to customers who have received a sample or attended a demonstration.