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This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1919 Excerpt: ...asphaltic cement in a cylindrical vessel 55 millimeters in diameter and 35 millimeters high shall be placed in an electrically heated oven at a temperature of 325 F and so maintained for a period of 5 hours. The oven shall have one vent in the top 1 centimeter in diameter, and the bulb of the thermometer shall be placed adjacent the vessel containing the asphaltic cement. Ductility. When pulled vertically or horizontally by a motor at a uniform rate of 5 centimeters per minute in a bath of water, a cylinder of asphaltic cement 1 centimeter in diameter at a temperature at which its penetration is 5 millimeters shall be elongated to the extent of not less than 10 centimeters before breaking. EPITOME OF THE PURPOSES OF CERTAIN SPECIFICATIONS FOR ASPHALTIC CEMENT. Impurities are a measure of the care with which the asphaltic cement has been refined and handled. Usually the presence of impurities in large quantities indicates a poor grade of asphalt. Water as an impurity would act as a diluent and would cause foaming in the kettle. Ash or mineral matter is not considered an impurity if it is a natural constituent of the asphaltic cement, but the mix and cementing value must be figured on the bitumen alone. Specific Gravity of the asphaltic cement should be over 1.000. The advantage of a specific gravity more than 1.000 is that there will be less tendency for water to float out the asphaltic cement. The specific gravity is raised by the presence of mineral matter. Asphaltic oils of a penetration satisfactory for paving purposes always have a specific gravity greater than 1.000. Paraffin base oil and air-blown products usually have a specific gravity less than 1.000. Fixed Carbon is a measure of the chemical constitution of an asphalt to some extent. Certain types...