Asphalt resistance

Acrylic-modified asphalt resistance to surface cracking, chalking and ultraviolet radiation flexibility oil and gas resistance parking lots off-highway streets highway shoulders... 

AC was initially developed in the United States to meet the need for an asphalt resistant to heavy traffic loads and aircraft loads. It is the most well-known type of asphalt, and it is used by almost all countries around the world. Many countries use gradation curves as they are specified by ASTM D 3515 (2010) (withdrawn in 2010), whereas European countries are obliged to compose gradation curves in accordance with the requirements of CEN EN 13108-1 (2008). 

Although the Marshall mix design (Asphalt Institute MS-2) is relatively old, it is currently used by several agencies/organisations because it uses simpler and cheaper laboratory equipment. However, many engineers believe that the way specimens are compacted does not simulate compaction on site. Additionally, the Marshall stability and flow do not adequately assess the asphalt shear strength. These two parameters do not ensure the asphalt resistance in permanent deformation (resistance to rutting). 

Asphalt resistance to fatigue depends on its composition and properties of constituent materials. Thus, each type of asphalt possesses different fatigue behaviour. This behaviour should be determined in order to design the pavement so that it does not crack prematurely. 

Structural Insulation Boards. Stmctural iasulation boards are made by a process similar to that used for iasulation board, with the exception of another additive which provides additional weight, strength, and water resistance. The additive is normally asphalt, which is added ia a... 

Bitumen Ionomers. Moisture-resistant asphalts (qv) have been prepared by reaction of metal oxides with acid-functionalized bitumens (75). Maleic anhydride or sulfur trioxide/trimethylamine complexes have been used successfully for introduction of acid groups into asphaltic bitumens. 

Fiber dmms can be produced to meet a wide variety of requirements. They can be constmcted with adhesives for water resistance, their interiors can be coated, their walls and ends can incorporate metal foil or asphalt-impregnated pHes, and their exteriors can be decorated by painting, varnishing, and silk screening for both ornamental and functional purposes. 

The shipment of many commodities may require special barriers on the sacks to impart resistance against hquids or vapors. Other treatments are used to provide grease resistance, acid resistance, and scuff resistance. Special coatings are used in sacks for packing commodities, eg, synthetic mbbers, asphalts, waxes (qv), and resins, to prevent the contents from sticking to the paper. 

At the roofing plant, coating asphalts ate blended with mineral stabiHzet such as finely ground limestone, slate, flyash, or traprock. The stabiHzet increases the coating asphalt s resistance to fire and foot-traffic and adds durabiHty. 

Polymeric Ma.teria.Is, The single-ply membranes are made from a wide variety of polymers. The following is a brief description of those polymers and their characteristics. There are three thermosetting-type elastomeric membranes as of this writing (1996) neoprene, CSPE, and EPDM. Neoprene is stiU used where oil resistance is needed. Eor instance. Hydrotech uses neoprene flashings, the base of which is hot-set in mbberized asphalt (see ElASTOL RS, SYNTHETIC-POLYCm.OROPRENE). 

CPA. Copolymer alloy membranes (CPAs) are made by alloying high molecular weight polymeries, plasticizers, special stabilizers, biocides, and antioxidants with poly(vinyl chloride) (PVC). The membrane is typically reinforced with polyester and comes in finished thicknesses of 0.75—1.5 mm and widths of 1.5—1.8 m. The primary installation method is mechanically fastened, but some fully adhered systems are also possible. The CPA membranes can exhibit long-term flexibiHty by alleviating migration of the polymeric plasticizers, and are chemically resistant and compatible with many oils and greases, animal fats, asphalt, and coal-tar pitch. The physical characteristics of a CPA membrane have been described (15). 

Standard Specification for Asphalt Shingles Made from Glass Felt and Surfaced with Mineral Granules Standard Test Method for Wind Resistance of Asphalt Shingles (Fan-Induced Method)... 

Procedures for testiug asphalt shingles resistant to wind blowup/blowoff when appHed on low slopes in accordance with manufacturer instmctions. Shingles are Type I, factory-appHed adhesive (self-sealing shingles) and Type II, lock-type, with mechanically interlocking tabs (ears). 

Wind Resistance. Asphalt shingles are certified to wind performance test standards on a continuous basis through independent third-party testing laboratories. Shingles that have passed the standard wind performance requirements, such as ASTM D3161, Standard Test Method for Wind Resistance for Asphalt Shingles, are identified by labels from the testing laboratory with whom they are in compliance. 

Tile. A versatile product, tile is traced back to ancient Greece, China, and Japan. Tile (35) has high fire resistance and is offered in a variety of textures and styles. Both clay and concrete tiles are relatively heavy and require a more robust stmcture than those used for asphalt shingles. 

Asphalt (bitumen) also occurs in various oil sand (also called tar sand) deposits which occur widely scattered through the world (17) and the bitumen is available by means of various extraction technologies. A review of the properties and character of the bitumen (18) suggests that, when used as an asphaltic binder, the bitumen compares favorably with specification-grade petroleum asphalts and may have superior aging characteristics and produce more water-resistant paving mixtures than the typical petroleum asphalts. 

Air-blown asphalts, more resistant to weather and changes ia temperature than the types mentioned previously are produced by batch and continuous methods. Air-blown asphalts, of diverse viscosities and flow properties with added fillers, polymers, solvents, and ia water emulsions, provide products for many appHcations ia the roofing industry. 

Durability. The term "durable" has several meanings, but in the present context it is used to describe an asphalt that possesses the necessary chemical and physical properties required for the specified pavement performance, being resistant to change during the in-service conditions that are prevalent during the life of the pavement. 

Both fiber-glass mats and polyester mats are used either individually or combined in SBS membrane sheets. Because of the elastomedc properties of the asphalt, SBS sheets have developed a reputation as being very tough and abuse-resistant. However, they do not have any better ultraviolet resistance than conventional asphalts, so most of the SBS sheets come with a factory-appHed surfacing of granules. 

Asphalt Asphalt is used as a flexible protective coating, as a bricklining membrane, and as a chemical-resisting floor covering and road surface. Resistant to acids and bases, alphalt is soluble in organic solvents such as ketones, most chlorinated hydrocarbons, and aromatic hydrocarbons. 

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. 

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