Weathering asphalt

Table VI. Asphalt Weather and Vapor-Barrier Coatings... 

For other recreational surfaces, such as mnning tracks, the installation techniques are quite different. Most are poured-in-place. An interlocking tile technique may be employed for tennis courts. In all cases, adequate provision for weathering and water drainage is essential. In general, the resiHent surfaces are installed over a hard base (see Fig. 4) that contains the necessary curbs to provide the finished level. Outdoors, asphalt is the most common base, and indoors, concrete. A poured-in-place polyurethane surface (14) is mixed on-site and cast from at least two components, an isocyanate and a filled... 

Sheet form, in widths as agreed upon by purchaser and seUer, composed of asphalt-saturated organic felt coated on both sides with asphalt and surfaced on weather side with mineral granules, except for selvage. Classified, in minimum net mass of granule-surfaced portion, as Type I, 3610 gm/m (74.0 lb/100 fC) and Type II, 3490 gm/m (71.5 lb/100 fC). 

Sheet form, 914 mm (36 in.) in width, or widths agreed upon by purchaser and suppHer, composed of asphalt-saturated organic felt with approximately half the width of weather side coated with asphalt and surfaced with mineral granules, for use as cap sheet in constmction of BUR. Materials covered by this specification, in minimum mass per unit area, are Type I, 1806 g/m (37.0 lb/100 fU) Type II, 2260 g/m (46.3 lb/100 fU) Type III, 1733 g/m (35.5 lb/100 fU) and Type IV, 2090 g/m (42.8 lb/100 fU). 

A number of laboratory procedures even more rapid than the accelerated Weather-o-meter have been described for the deterrnination of expected weatherabihty of coating asphalts. Research sponsored by the Asphalt Roofing Manufacturers Association describes a stepwise procedure to determine changes in the cmde asphalt source (see Asphalt). 

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. 

In addition to the paving grades of emulsions, a variety of products are available that are suitable for industrial uses, for paper sidings, and for use in the roofing appHcation field. Asphalts emulsified with colloidal clays are especially suitable for outdoor appHcations because of their exceUent weathering properties. Some of these products have been adapted for use with roofing systems, either with bmsh or spray appHcation. 

Type IV asphalt is not common except in very hot climates. It has softening points between 96 and 107°C with penetration at 25°C between 12 and 25 mm /10. It is for roof slopes greater than 1 per 12, and is also called special steep asphalt. Type IV asphalt is used on flashings and in hot climates to keep the roofing system from sliding off the roof in hot weather. 

Goal Tar. In roofing, coal tar is used as mopping bitumen in between 15 and 20% of the BUR roofs installed. Coal-tar pitch and asphalt are considered incompatible and should not be mixed. If mixed, an oily exudate is formed that plasticizes the bitumen, and the mixture remains soft and does not weather well. For this reason, if coal tar is used in BUR systems the felts must be coal-tar saturated. There has been some success using asphalt-coated fiber-glass mat felts with coal-tar pitch. However, this has only been done for a limited number of years so the actual compatibiHty is not fully known. 

Container Insulation Tanks containing materials above atmospheric temperature may require insulation to reduce loss of heat. Almost any of the commonly used insulating materials can be employed. Calcium silicate, glass fiber, mineral wool, cellular glass, and plastic foams are among those used. Tanks exposed to weather must have jackets or protective coatings, usually asphalt, to keep water out of the insulation. 

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. 

It has been shown that inclusion of fine mbber particles in asphalt reduces the cracking of pavement in adverse weather conditions [60,61]. There are two methods for introducing ground waste mbber into asphalt, namely, wet and dry processes. Wet process is carried out at 170°C-220°C for 45-120 min. Rubber particles absorb components with similar value of solubility parameter (5) from the asphalt, causing them to swell. The interaction between mbber and asphalt is mainly of physical nature. In the dry process, mbber is used as a replacement for part of the aggregate and is added to the mineral material before the latter is mixed with the asphalt binder. Addition of mbber greatly improves the elasticity of the binder and generally lowers its brittle point. Incorporation of GRT... 

Peaks observed at 5.90 xm and 8.70 xm were thought to reflect oxidative effects on the asphaltic material, while asphaltic sulfoxide and sulfone were tentatively inferred from bands at 9.76, 8.66, and 7.72 xm. The 12.34/13.88, 12.34/7.27, and 6.25/13.88 xm ratios tended to show the greatest difference between different samples. When the ratio 12.34/7.27 xm versus 12.34/13.88 ixmwere plotted graphically, the intermediate fuel oils behaved similarly [53]. Weathering caused fuel oils to fall below the curve although with asphalts the effect was... 

This test (ASTM D529) evaluates the relative weather resistance of asphalt used for protective-coating applications, especially for roofing. No direct measure of outdoor life or service can be obtained from this test. Methods for preparing test panels (ASTM D1669) and failure-endpoint testing (ASTM D1670) are available. 

MASJEDDAGHI area is located in northwest of Iran and in the north of East Azerbaijan province adjacent to the boundary between Iran and Azerbaijan. The area s latitude is between 38° 52 03" and 38° 53 22" and its longitude is in the range of 45° 56 05" and 45° 58 29". Its total area is about 8 Km. The access road is JOLFA - SIAM RUD asphalted road. The highest elevation is 950 m from sea level. Weather in this region is hot in the summer and cold in the winter. 

The developer claims that the technology is applicable for remediation at refineries, wood treating sites, old town gas plants, and at sites where weathered hydrocarbons contain a substantial fraction of polar asphaltic components. 

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