Natural Weathering of Mineral Stabilized Asphalt Coatings on Organic FeltU.S. National Bureau of Standards, 1969 - 15 pages Sixteen years of outdoor weathering of laboratory-prepared smooth-surface and mineral-surfaced, felt-base roofing specimens has provided information on the effects of mineral additives on the durability of coating-grade roofing asphalts. Six finely divided mineral additives (blue black slate, clay, dolomite, fly ash, mica, and silica) were evaluated at concentrations up to 60 percent in California, Mid Continent and Venezuela asphalts. The mineral-surfaced specimens are all performing satisfactorily, and show only minor degrees of degradation. Of the smooth-surfaced specimens, the Mid-Continent asphalt performed the best and the California asphalt the poorest. The mica and blue black slate increased the durabilities of all three asphalts at all concentrations and two coating thicknesses. Fly ash, clay, dolomite, and silica were beneficial in some combinations, but had little effect in others. In general, these early results from outdoor exposure tend to corroborate the results obtained on these coatings exposed in weatherometers. (Author). |
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Page 5
... sheet of dextrin - coated paper , two sheets of Kraft paper and a piece of tempered hardboard were successively placed over the coating , and the assembly was put into the hydraulic press . The press was closed and the pressure raised ...
... sheet of dextrin - coated paper , two sheets of Kraft paper and a piece of tempered hardboard were successively placed over the coating , and the assembly was put into the hydraulic press . The press was closed and the pressure raised ...
Page 6
... sheet of 12 - in wide Kraft paper three feet long was fastened to its end , about 4 in in front of the doctor bar . In order to be assured that the doctor bar was at the proper distance from the machine bed , a blank run was made in ...
... sheet of 12 - in wide Kraft paper three feet long was fastened to its end , about 4 in in front of the doctor bar . In order to be assured that the doctor bar was at the proper distance from the machine bed , a blank run was made in ...
Page 8
... sheets lost . failure , cannot be used as an early warning of impending failure . While early cracking of the coating on shingles may be startling to an uninformed observer , the data in tables 6 and 7 for smooth- surface specimens show ...
... sheets lost . failure , cannot be used as an early warning of impending failure . While early cracking of the coating on shingles may be startling to an uninformed observer , the data in tables 6 and 7 for smooth- surface specimens show ...
Common terms and phrases
60 percent aluminum aluminum-base specimens appearance Applied areas asphalt coatings ASTM base Black Slate 25 blistering Blue Black Slate Building Building Science Series Bureau of Standards California asphalt Cement Center cents Characteristics Clay Column COMMERCE concentrations consists containing corresponding cracking criteria deterioration differences direction divisions doctor bar Dolomite durability early effects exposed exposure failed failure felt-base specimens FIGURE Fly Ash Government granule-surfaced specimens granules grid half heated industry Institute Kraft paper listed longer Loss on ignition losses machine materials measurement method Mica Mid-Continent asphalt mils mineral additives Months Ratio Months National Bureau observed Office Organic panel passed performances period physical prepared procedure produced Properties provides Ratio Months Ratio reference reported Research rolls roofing saturated felt sheets shingle Silica smooth smooth-surface smooth-surface specimens spalling surface TABLE technical Technology temperature tests three asphalts Venezuela asphalt Washington weather weatherometer tests