26 BULLETIN 105 ? U. S. DEPARTMENT OF AGRICULTURE. 



Table 30. — Analysis of asphaltic petroleums used in experiments at Miami, Fla. 



Character. 



Experi- 

 ments 

 3, 5, 6. 



Specific gravity 25°/25° C 0. 960 



Flash point ° C : 42 



Burning point °C j 67 



Viseositv, Engler, specific i 152. 4 



Per cent of loss at 163° C I 27. 53 



Float test on residue (50° C.) ' s2'19" 



Percent of total bitumen insoluble in 86° B. naphtha 10.40 



Per cent of fixed carbon ! 5. 01 



Per cent soluble m CSs (total bitumen) 99. 94 



Per cent of organic matter insoluble .06 



Per cent of inorganic matter insoluble .00 



Total 100.00 



0.992 

 105 

 145 

 °9.0 

 16.33 

 3 2'40" 

 10. S3 

 5.82 



99.94 

 .04 

 .02 



1 At 25° C, 50 c. c. 



At 100° C, 100 c. c. 



3 Soft, sticky, with slight flow. 



Experiment No. 1. — Semipenetration method — Cold, light oil. 



Location: From station 0+00 to station 0+96. 

 Length: 96 feet. 



Method. — The old surface was scarified, regraded, and left loose to 

 a depth of about 2 inches. Rain during the night previous to oiling 

 caused the surface to rebond, and it was again broken to a depth of 2 

 inches and smoothed with rakes. The light oil was applied at the 

 rate of 0.9 gallon per square yard and allowed to soak in for two 

 hours before sanding, after which the surface was rolled. Owing to 

 the quantity of fine material in the scarified surface, very little pene- 

 tration was accomplished, but the oil was absorbed to a considerable 

 extent. On rolling, the surface cracked and waved badly. Several 

 rains with a light rolling after each improved its condition to a great 

 extent, but the promise of ultimate success was not great. 



Experiment No. 2. — Surface treatment — Cold, light on. 



Location: From station 0+96 to station 5+49. 

 Length: 453 feet. 



Method. — The old surface was scarified, regraded, and water-bound. 

 It was then swept clean and the oil was applied at the rate of 0.5 

 gallon per square yard by means of pouring pots. After vigorously 

 brooming the oil, the surface was sanded and rolled. 



From station + 96 to station 2 + 85 the surface was very damp 

 from rain the previous night. The oil was allowed to stand from two 

 hours at station + 96 to six hours at station 2 + 85. It was sanded 

 late in the afternoon and rolled the following morning. From station 

 2 + 85 to station 3 +90 the sand was spread immediately after the oil 

 was applied. From station 3 + 90 to station 5 + 49 the oil stood from 

 three to six hours before sanding. The sanding was barely com- 



