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Cork insulation; a complete illustrated textbook on cork insulation ...

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230 CORK INSULATION<br />

Flash Point is a measure of the amount of volatile hydrocarb<strong>on</strong>s<br />

that are present in the Asphalt cement, and of the readiness of the<br />

asphalt to decompose by heat.<br />

Penetrati<strong>on</strong> is a measure of the c<strong>on</strong>sistency of the Asphalt cement.<br />

It is merely a quick, c<strong>on</strong>venient test for checking up numerous sam-<br />

ples. The penetrati<strong>on</strong> is expressed in degrees, and 1/10 m.m. equals<br />

<strong>on</strong>e degree. The penetrati<strong>on</strong> to be desired will depend up<strong>on</strong> the<br />

climate, the ductility and adhesiveness of the Asphalt cement.<br />

Loss by Volatilizati<strong>on</strong> is a measure of the amount of light hydrocarb<strong>on</strong>s<br />

that are present in Asphalt cement, v^rhich indicates its tendency<br />

to oxidize and to lose its ductility and penetrati<strong>on</strong>.<br />

Ductility is a measure of the ability of an Asphalt cement to expand<br />

and c<strong>on</strong>tract without breaking or cracking. The same asphalt<br />

at a higher penetrati<strong>on</strong> should have a higher ductility, so all ductility<br />

tests should be based <strong>on</strong> a certain definite penetrati<strong>on</strong> regardless of<br />

temperature, or should be based <strong>on</strong> a temperature of 32° F. (0° C).<br />

Ductility is also a measure of the cementing strength.<br />

Viscosity is a measure of the ability of the Asphalt cement to im-<br />

part plasticity and malleability.<br />

The methods of testing to be followed in c<strong>on</strong>necti<strong>on</strong> with<br />

Specificati<strong>on</strong> for Asphalt Cement for Cold Storage Insulati<strong>on</strong>, are<br />

those of the American Society for Testing Materials, as<br />

follows:<br />

:<br />

(a) Determinati<strong>on</strong> of Bitumen in Asphalt Pioducts (Deducted<br />

from 100 per cent, equals Purity) A. S. T. M., D4-23T.<br />

(b) Softening Point of Bituminous Materials (Ring and Ball<br />

Method) A. S. T. M., D36-24.<br />

(c) Flash and Fire Points of Bituminous Materials (by the Cleveland<br />

Open Cup Method) A. S. T. M., D92-24.<br />

(d) Penetrati<strong>on</strong> of Bituminous Materials, A. S. T. M., D5-25<br />

(e) Loss <strong>on</strong> Heating of Oil and Asphaltic Compounds, A. S. T. M.,<br />

D6-20.<br />

(f) Ductility of Bituminous Materials, A. S. T. M., D113-22T.<br />

(g) Sulphur in Bituminous Materials (Ash Free Basis) A. S. T. M.,<br />

D29-22T.<br />

The Kansas City Testing Laboratory, in its Bulletin No.<br />

15, publishes values for the compositi<strong>on</strong> of natural and petroleum<br />

asphalts, as follows<br />

1.—COMPOSITION OF NATURAL ASPHALTS.

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