Asphalt applications

The primary use of prometon, introduced in 1959, is for total vegetation control in noncrop areas around the farm, on industrial sites, and for use in and under asphalt. Application rates are from 10 and 601b/A/yr (11 and 67kg/ha/ yr), 10 to 30 times higher than for atrazine, but the treated areas are much smaller (Capel et al, 1999). Prometon is highly persistent with an average field half-life of 500 days. 

Hot asphalt applications had been used for many years in concrete tanks, inner lined with brick for similar service, and also, of course, unlined wood tanks made from timber, and small pickling tanks made by hollowing out cavities in granite blocks. But the use of hot asphalt as a liner for steel tanks had been unsatisfactory due to the erratic cold flow of the asphalt which demonstrated selective adhesion to steel and so would tear and open cracks in the membrane system in the areas of cold flow below the points where it adhered. To overcome this difficulty, a number of inventive persons experimented with the manufacture of asphalt sheet lining materials, similar in form to the sheets of natural rubber, in which the asphalt was compounded with various admixtures, including rubber. These asphaltic compound sheets were then warmed sufficiently to make... 

Melt and pour (or squeegee)-used for hot asphalt applications and some other similar materials. 

Hot asphalt applications to prevent chemical attack are probably the oldest of all coatings and surfacing materials. As a natural occurrence, asphalt ponds and deposits have been found in many parts of the world and from earliest times, natives have heated the asphalt up to bring it to a flowable consistency, then spread it on surfaces they wished to protect. With the refining of petroleum "still bottom residues," similar to naturally occurring asphalts, were employed in similar ways, and being waste products, were less expensive to use. 

Ground up scrap tires are beginning to find use in some special asphalt applications. 

The test is normally performed on fillers that will be used in mastic asphalt applications. However, useful information may be provided for other asphalt performance criteria (Vansteenkiste and Vanelstraete 2008). 

When scaling is less than approximately 10 mm in depth, temporary repair is carried out by micro-surfacing otherwise, the surface should be overlaid by asphalt. Application of the proper amount of tack coat and a clean surface are of vital importance. 

Vacuum tower residuum properties can be set in various ways. When distillate production is to be maximized, the amount of gas oil allowed to remain in the bottoms stream must be minimized, and this material, usually 0 to 5 degrees API, is blended into residua fuels. This is called pitch operation. In asphalt operation, some gas oil must be left in the residuum in order to provide the proper degree of plasticity. The gravity of asphalt streams usually falls in the range of 5 to 8 degrees API. Not all crudes can be used to make asphalt since this is a question of whether or not the particular residuum has the proper composition of matter to render it suitable in asphalt applications. This question can only be answered experimentally and is usually contained in a detailed crude assay. Pitch operation can be practiced with any type of crude. 

Fig. 12-11 Schematic diagram of a typical microsurfacing paver. Courtesy Akzo Nobel Asphalt Applications Inc.

Road paving. This includes bitumen, cutbacks and fluxed bitumen as well as emulsions. Each of these products is subject to very special application techniques. This list is completed by the use of poured asphalt, even though this product is better suited to smaller surfaces sidewalks, courts, etc., than to pavements. Since the middle of the 1980 s, air-blown bitumen is no longer used for road construction. 

Applications. These materials are stiU in developmental infancy. Current production is limited to one commercial process in Europe and a demonstration-scale process in North America. The lignins produced in these processes have potential appHcation in wood adhesives, as flame retardants (qv), as slow-release agents for agricultural and pharmaceutical products, as surfactants (qv), as antioxidants (qv), as asphalt extenders, and as a raw material source for lignin-derived chemicals. 

Oil field uses are primarily imidazolines for surfactant and corrosion inhibition (see Petroleum). Besides the lubrication market for metal salts, the miscellaneous market is comprised of free acids used ia concrete additives, motor oil lubricants, and asphalt-paving applications (47) (see Asphalt Lubrication AND lubricants). Naphthenic acid has also been studied ia ore flotation for recovery of rare-earth metals (48) (see Flotation Lanthanides). 

Finally, the combined reinforcing effect and high absorption capacity of asbestos fibers have been exploited in a variety of appHcations to increase dimensional stabiHty, typically in vinyl or asphalt tiles and asphalt toad surfacing. Figure 9 summarizes, as of 1984, the various classes of application for asbestos fibers in combination with other materials. The diagram shows that in recent years, most industrial appHcations have evolved towards composite materials where the fibers are bonded within an organic or inorganic matrix. 

Venmri scrubbers have been applied to control PM emissions from utility, industrial, commercial, and institutional boilers fired with coal, oil, wood, and liquid waste. They have also been applied to control emission sources in the chemical, mineral products, wood, pulp and paper, rock products, and asphalt manufacrnring industries lead, aluminum, iron and steel, and gray iron production industries and to municipal solid waste incinerators. Typically, venturi scrubbers are applied where it is necessary to obtain high collection efficiencies for fine PM. Thus, they are applicable to controlling emission sources with high concentrations of submicron PM. 

Asphalt Manufacture Saleable asphalts are produced from the residua of selected crudes. The residuum itself may be sold as straight reduced cuts to make it easier to handle, producing the so called cut-back asphalts. Another variation is air blown or oxidized asphalts for improved tenacity, greater resistance to weathering, and decreased brittleness. Emulsified asphalts are made for application at relatively low temperatures. 

Asphalt- based Applicable Applicable Applicable contaminant may act as a binding agent Applicable if waste is first neutralized Not applicable Not applicable... 

Chemical Designations - Synonyms Liquid asphalt Petroleum asphalt Slow-curing asphalt Chemical Formula Not applicable. 

The heaviest products obtained directly from oil arc lubricants, waxes, asphalt, and coke. These products have both domestic and industrial uses. Lubricants, for example, are applied in the operation and maintenance of industrial equipment and machinery. Asphalt, because it is not reactive to chemicals in the environment, is a superb material of construction in the building of roads and in roofing. It is also used in the waterproofing of concrete, the manufacture of black paints, and as a material lor tire threads, battery housing, electrical insulation, and other applications. The heaviest of all the petroleum products, coke, is used extensively as a major component of industrial electrodes and as a commercial fuel. 

The differences between asphalt and coal tar in relation to their application as pipeline coatings require comment. 

The AWWA C-203 Standard remains a widely used specification suitable not only for the materials, but also for their associated reinforcing wraps and application procedures. The standard has been regularly updated. Hot-applied asphaltic and coal-tar coatings with their priming systems are now well classified, described and specified in BS 4164 1967 (coal tar) and BS 4147 1967 (asphalt), but no guidance is given in these specifications to application procedures. 

Recent trends in protective coatings used on buried pipelines have been away from reinforced hot applied coal tar and asphalt enamels and butyl rubber laminate tapes, particularly where applied over-the-ditch . The more recently developed coatings based on fusion bonded epoxies, extruded poly-ethylenes, liquid-applied epoxies and polyurethanes, require factory application where superior levels of pipe preparation and quality control of the application process can be achieved. 

Tapes are produced in both temperate and tropical grades and heavy duty versions can be supplied for application under hot mastic asphalts at field joints of concrete weight-coated pipelines. Wrapping of complex shapes may be achieved by first profiling with a bituminous filler compound. 

J. Romocki. Application of N,N-dialkylamides to reduce precipitation of asphalt from crude oil. Patent WO 9418430,1994. 

Naslund (2001) investigated a combined system with river water as base load and snow cooling as back up, for an industrial application. The cooling need was 1,500 kW at 5 °C and 1,500 kW at 15 °C, continuously. The needed snow amount was 78,800 ton, stored in a 120 x 100 x 3 m3(L x W x H) pond with water tight asphalt bottom. The estimated investment cost was about 950,000 A. 

---