Roofing asphalt

Diphenylamine antioxidants are also widely used to stabili2e roofing asphalts, lubricating greases, silicone enamels, polyamides, acetal resias, and... 

Hoidal CR, Hall AH, Robinson MD, et al. 1986. Hydrogen sulfide poisoning from toxic inhalations of roofing asphalt fumes. Ann Emerg Med 15 826-830. 

The effect of make-up of roofing asphalts on weathering properties, in terms of the fractions asphaltenes, resins, and oils, has been studied by Thurston (120). Increase of either asphaltenes or oils reduced resistance to weathering, while apparently an optimum content of resins aided permanence under exposure. Weathering properties were dependent not only on the quantities but also on the sources of these fractions, but the effect of source was not sufficiently clarified. 

Because they become brittle at low temperatures, another opportunity exists for substantial improvements of both paving and roofing asphalts. Severe winters cause unusual damage to pavements and precautions must be taken in the application of prepared roofings in such weather. A practical solution to this problem would be of considerable value to the industry. 

A substantial fraction of the coal tar produced continues to be used as fuel as well as for road asphalt and roofing asphalt. For these purposes the tar is distilled up to the point where thermal decomposition starts. This base tar is then diluted with creosote oil to ensure satisfactory rapid drying. Similar tars are used to impregnate felt and paper for waterproofing materials. 

Asphalt is a thermoplastic material recovered from distillation bottoms. There is some evidence that it may have been used by Noah to seal the ark. Today, the major uses are in paving for highways and for roofing. Asphalt, depending on its geologic origin, may exhibit Newtonian or non-Newtonian properties. 

Roofing, asphalt or tar satmated felt built-up, roll, and shingle—mfpm... 

Niemeier RW, Thayer PS, Menzies KT, et al. 1988. A comparison of skin carcinogenicity of condensed roofing asphalt and coal tar pitch fumes. In Polynuclear Aromatic hydrocarbons A decade of progress, 609-647. 

Evaluation of VOC Emissions from Heated Roofing Asphalt U.S. Environmental Protection Agency, 1991, EPA/600/S2-91/061. 

S. H. Greenfeld, The Effects of Mineral Additives on the Durability of Coating Grade Roofing Asphalts, Building Materials and Structures Report 147, National Bureau of Standards, Washington, D.C., 1956. 

Synonyms/Trade Names Asphalt Asphaltum, Bitumen (European term), Petroleum asphalt, Petroleum bitumen, Road asphalt. Roofing asphalt ... 

Roll roofing- Asphalt roofing products manufactured in roll form. 36-inch wide rolls with and 108 square feet of material. Weights are generally 45 to 90 pounds per roll. 

Asphalt Copper EPDM rubber Zinc roofing asphalt... 

From the above demonstration, it can be noted that micelle structures are predominant in asphalt with a higher asphaltene content. Three different types of asphalt such as sol (micelle, supermicelle, giant supermicelle), sol-gel (supermicelle, giant supermicelle), gel (liquid crystal) asphalt, can be defined. Most of the paving asphalts belong to the sol-gel type of asphalt, and roofing asphalt belong to the gel (air blown) type of asphalt. 

Because there are so many partial combustion and pyrolysis processes that favor production of PAHs, these compounds are encountered abundantly in the atmosphere, soil, and elsewhere in the environment from sources that include engine exhausts, wood stove smoke, cigarette smoke, and charbroiled food. Coal tars and petroleum residues such as road and roofing asphalt have high levels of PAHs. Some PAH compounds, including benzo[a]pyrene, are of toxicological concern because they are precursors to cancer-causing metabolites. 

The length of the blow depends on desired product properties, sueh as softening temperature and penetration rate. A typical plant blows four to six batches of asphalt per 24-hour day. There are two primary substrates for roofing asphalt - organic (paper felt) and fiberglass. The production of felt-based roofing shingles consists of ... 

---