The uses of bitumenPrint
The uses of bitumen
The vast majority of bitumen is used by the construction industry, as a con- stituent of products used in paving and roofing. Excellent waterproofing characteristics and thermoplastic behaviour make it ideal for a wide range of applications. At el evated temperatures (typically between 100 and 2008C) it acts like a viscous liquid, and can be mixed with other components and manipulated and formed as required. Once cooled, it is an inert solid that is durable and hydrophobic (repels water).
Various terms are used to describe conventional bitumen such as straight run, paving grade and penetration grade (or ‘pen grade’). When people use these terms they normally mean grades of bitumen that can be produced at a conventional refinery in a relatively simple way.
The vast majority of bitumen used in asphalt for road construction is conven- tional bitumen; that is why it is often known as paving grade. The term ‘pen grade’ is short for penetration grade, and reflects the fact that this type of product is often classified (in Europe and parts of Asia) using the penetration test. The term straight run refers to the fact that this type of bitumen is often produced direct from the vacuum distillation process, without any further modification.
Current estimates put the world use of bitumen at approximately 102 million tonnes per year (Eurobitume and the Asphalt Institute, 2011), and about
85% of all the bitumen produced is used in asphalt for the construction of roads and other paved areas. Typically, asphalt will contain approximately 5% by mass of bitumen, with the remaining 95% consisting of a mixture of mineral aggregates and much finer materials such as limestone filler
A note on terminology is worth making at this point – ‘asphalt’ is a generic term used to describe a range of road surfacing products containing primarily bitumen and mineral aggregates. A few alternative terms exist including hot mix asphalt (HMA) and asphalt concrete (AC). In this book the term ‘asphalt’ will be used throughout. Asphalt is often referred to incorrectly in the media and in common parlance as tarmac (short for tarmacadam). Tarmacadam is a road surfacing product using coal tar as a binder and has not been used in road construction for over 30 years.
A further 10% of global bitumen production is used in roofing applications, and the remaining 5% is used mainly for sealing and insulating purposes in a variety of building materials, such as pipe coatings, carpet backing, joint sealants and paint.
The extremely wide range of uses for bitumen is demonstrated by the number of registered uses in Europe under the requirements of the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) regulations, which require all chemical substances and associated uses to be registered. Table 1.2 provides an overview (Eurobitume, 2013).
Bitumen is available in a variety of grades. Specifications are used across the world to define these grades to meet the needs of the applications, climate, loading conditions and end use. They are usually based on a series of standard test methods that define the properties of each grade such as hardness, viscosity, solubility and durability.
Bitumens are also used to manufacture mixtures or preparations. In these products, bitumen is often the principal component, but they can contain significant proportions of other materials to meet end use requirements. These mixtures are chemically classified as bitumen preparations.
Cut-back bitumen and fluxed bitumen. Cut-back and fluxed bitumen products are preparations in which the viscosity of the bitumen has been reduced by the addition of a solvent, normally derived from petroleum. Typically the solvents used are white spirit, kerosene and
Fence post coating
Paved barn floors, barnyards, feed platforms
Protecting tanks, vats
Protection for concrete structures
Tree paints (protective)
Buildings and industrial paving
Water and moisture barriers (above and below ground)
Floor compositions, tiles, coverings
Insulating fabrics, papers
Cement waterproofing compounds
Glass wool compositions
Insulating fabrics, felts, papers
Joint filler compounds
Laminated roofing shingles
Liquid roof coatings
Acoustical blocks, compositions, felts
Damp-proofing coatings, compositions
Insulating board, fabrics, felts, paper
Air-drying paints, varnishes
Canal linings, sealants
Hydraulics and erosion control
Catchment areas, basins
Dam linings, protection
Drainage gutters, structures
Mattresses for levee and bank protection
Membrane linings, waterproofing
Sand dune stabilisation
Sewage lagoons, oxidation ponds
Conduit insulation, lamination
Battery boxes, carbons
Electrical insulating compounds, papers, tapes, wire coatings
Junction box compound
Cable splicing compound
Well drilling fluid
Armoured bituminised fabrics
Sawdust, cork, asphalt composition
Acid-proof enamels, mastics, varnishes
Air-drying paints, varnishes
Anti-corrosive and anti-fouling paints
Anti-oxidants and solvents
Base for solvent compositions
Baking and heat-resistant enamels
Boat deck sealing compound
Rubber, moulded compositions
Shoe fillers, soles
Paving (see also agriculture, hydraulics,
Airport runways, taxiways, aprons
Bridge deck, surfacing
Floors for buildings, warehouses, garages
Highways, roads, streets, shoulders
Kerbs, gutters, drainage ditches
Parking lots, driveways
Portland cement concrete underseal
Paved ballast, sub-ballast
Paved crossings, freight yards, station platforms
Gymnasiums, sport arenas
Playgrounds, school yards
Swimming and wading pools
Tennis courts, handball courts
Synthetic playing fields and running track surfaces
Bitumen emulsions. Bitumen emulsions are products in which droplets of bitumen or bitumen preparation are dispersed in an aqueous medium. An emulsifier is used to stabilise the mixture. Bitumen emulsions permit the handling, transport and application of bitumen at lower temperatures, and are used mainly in road surfacing applications.