Asphalt definition

The influence of the composition of asphalt has been recognized, for many years, as being an important factor in controlling the performance of such materials. Furthermore, rheological properties have always been associated with composition but, in order to utilize compositional data effectively, more definitive correlations between composition and properties are needed (46—48). 

Penetration (ASTMD5). This is a commonly used consistency test. It involves the deterrnination of the extent to which a standard needle penetrates a propedy prepared sample of asphalt under definitely specified conditions of temperature, load, and time. The distance that the needle penetrates in units of mm/10 measured from 0 to 300, is the penetration value. Soft asphalts have high penetration values. 

A mobile source of air pollution can be defined as one capable of moving from one place to another under its own power. According to this definition, an automobile is a mobile source and a portable asphalt batching plant is not. Generally, mobile sources imply transportation, but sources such as construction equipment, gasoUne-powered lawn mowers, and gasoline-powered tools are included in this category. 

There is a wide range of conversion levels. The term maximum conversion type has no precise definition but is often used to describe a level of conversion, where there is no net fuel oil manufactured. A fuel products refinery with specialities may manufacture lubricating oils, asphalts, greases, solvents, waxes and chemical feed stocks in addition to the primary fuel products. The number and diversity of products will naturally vary from one refinery to another. Refineries produce chemical feed stocks for sale to the chemical affiliates and do not have responsibility for the manufacture of chemical products directly. Both operations may be carried out at the same physical location but the corporate product responsibilities are usually separate. 

Used oil distillation bottoms. When used oil is recycled, residues (called distillation bottoms) form at the bottom of the recycling unit. To promote the recycling of used oil and the beneficial reuse of waste materials, U.S. EPA excluded these residues from the definition of hazardous waste when the bottoms are used as ingredients in asphalt paving and roofing materials. 

The classic definition of asphaltenes is based on the solution properties of petroleum residua in various solvents. The word asphaltene was coined in France by J.B. Boussingault in 1837. Boussingault described the constituents of some bitumens (asphalts) found at that time in eastern France and in Peru. He named the alcohol insoluble, essence of turpentine soluble solid obtained from the distillation residue "asphaltene", since it resembled the original asphalt. 

In addition, the crude oils available today to the refinery are quite different in composition and properties to those available some 30 years ago (Swain, 1998 Speight, 1999). The current crude oils are somewhat heavier insofar as they have higher proportions of nonvolatile (asphaltic) constituents. In fact, by the standards of yesteryear, many of the crude oils currently in use would have been classified as heavy feedstocks, bearing in mind that they may not approach the definitions used today for heavy crude oils. Changes in feedstock character, such as this tendency to heavier materials, require adjustments to refinery operations to handle these heavier crude oils to reduce the amount of coke formed during processing and to balance the overall product slate. 

Non-Polymeric Materials. Waxes, soaps, greases, asphalts, oils. Complex mixtures of hydrocarbons of different molecular weight when treated to a common thermal history (such as slow program-cooling from above the melt) give complex but highly repeatable characteristic DSC melting profiles (16,17). In the absence of any other forensic evidence, these thermal profiles should be sufficiently specific and repeat-able to be definitive evidence. 

In modern terms, asphaltene is conceptually defined as the n-pentane-insoluble and benzene-soluble fraction whether it is derived from coal or from petroleum. There are a number of procedures used to isolate asphaltene (2-7), all of which appear to be reproducible (8) but do not necessarily provide equivalent end-products. The similarity between coal- and petroleum-derived asphaltenes begins and ends at the definition of the separation procedure. Puzinauskas and Corbett s (9) comments on asphalt may be paraphrased and applied to asphaltene. They state that the broad solvent classification is unfortunate it leads to misconceptions that petroleum and coal materials are alike, or at least similar. However, these two classes of materials differ not only in their origin, mode of manufacture and uses, but also in their chemical composition and physical behavior. 

Definition Ester of erucyl alcohol and stearic acid Uses Lubricant, slip agent, antiblocking agent, and mold release agent for plastics, crayons, petrol, prods., asphalts, inks, metals, textiles mold release agent for thermoplastic resins in inj. molding defoamerand water repellent in industrial/household applic. 

Definition Mixt. of mono-, di-, and triglycerides derived from palm oil Uses Emollient, emulsifier, stabilizer, dispersant, opacifier in cosmetics, pharmaceuticals dispersant for clay systems sec. emulsifier and stabilizer for asphalt emulsions emulsifier, dispersant in foods Trade Name Synonyms Cremao CE-34 [Aarhus Oliefabrik MS http //www.aarhus.com]] Monomuls 60-30 t[Grunau GmbH http //WWW. gruenau-... 

By definition, the subgrade is considered as one layer. Thus, in the typical flexible pavement that consists of unbound layer (base/sub-base) and bitumen-bound layers all consisting of asphalts with the same mechanical properties, the number of distinct layers is three. 

For a better clarification of the terms maintenance and rehabilitation and for the purpose of this book, the definitions proposed by the Asphalt Institute will be adopted. 

Generally, asphalt can be fractionated into four important fractions saturates, aromatics, resins, and asphaltenes . The classic definition of fractions of asphalts is based on the solution properties of petroleum residuum in various solvents. A complete fractionation scheme is given in Figure 1 (1) the oil constituents are propane soluble (2) resins are n-pentane soluble but propane insoluble (3) asphaltenes are toluene soluble but n-pentane insoluble and (4) preasphaltenes are insoluble both in n-pentane and toluene. The fractionated part of oil is generally considered to be a combination of saturates and aromatics. The polarity of these four fractions increases from saturates, to aromatics, to resins, to asphdtenes. 

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