DUST PBEVENTION AND ROAD PRESERVATION, 1915. 29 



Table 30. — Materials and cost data for surface-treatment experiments on Falls Road. 



i 



1 



OCX 



dS.! 



Description. 



Quantity of mate- 

 rials (per square 

 yard). 



Cost per square 

 yard. 



.1 



Bituminous material. 



Length of 

 section. 



Area of 

 section. 



Bitumi- 

 nous ma- 

 terial. 



Gravel.i 



Bitumi- 

 nous ma- 

 terial. 



Gravel 

 (hauling 

 included). 



1 

 2 



3 



5 



....„ 



1 



Asphalt petroleum (cold) 



Residual asphaltic petroleimi 

 (hot) 



Feet. 

 4,575 



4,386 

 7,941 

 5,718 

 5,880 



Sq,. yds. 

 7,625 



7,310 

 13,235 

 9,530 

 9,800 



Gallon. 

 0.525 



.739 

 .423 

 .538 

 .596 



Cu. yds. 

 0.0149 



.0164 

 .0151 

 .0150 

 .0150 



Cents. 

 2.63 



5.54 

 4.02 

 4.57 



4.77 



Cents. 

 3.84 



4.25 



3 



4 



5 



Coal-tar preparation (cold) 



Refined water-gas tar (cold). . . 



3.53 

 3.67 

 3.65 











Description. 



Cost per square yard. 



Total cost. 



1 



Bituminous material. 



Clean- 

 ing sur- 

 face. 



Heat- 

 ing bi- 

 tumi- 

 nous 

 mate- 

 rial. 



Haul- 

 ing and 

 apply- 

 mghot 

 mate- 

 rial.2 



Spread- 

 ing 

 gravel. 



Roll- 

 ing. 



Miscel- 

 lane- 

 ous. 3 



Per 

 square 

 yard. 



Per 

 mile, 

 15-foot 

 road. 



1 

 2 



Asphaltic petroleum (cold) 



Residual asphaltic petroleum 

 (hot) 



Cents. 

 0.05 



.05 

 .01 

 .04 

 .08 



Cents. 

 0.41 



Cents. 

 0.23 



.37 

 .12 

 .24 

 .32 



Cents. 

 0.32 



.71 



.38 

 .55 



.86 



Cents. 

 0.05 



.10 



.04 

 .04 

 .02 



Cents. 

 0.66 



.68 

 .38 

 .52 

 .51 



Cents. 

 7.77 



12.11 



8.48 

 9.63 

 10.21 



$683.76 



1,065.68 

 746. 24 

 847.44 

 898. 48 



3 



4 



5 



Coal-tar preparation (cold) 



Refined water-gas tar (cold) 



Refined coal tar (hot) 









1 2,500 pounds equals 1 cubic yard. 

 2 Hauled to road in distributor. 



3 General expense and superintendent. 



INSPECTION REPORT. 



Tlie following report describes the condition of tlie experiments 

 on the Falls Road on the date of last inspection, April 27, 1916. 



Experiment No. 1. — ^At the time of the inspection the surface did 

 not appear to carry a distinct mat or carpet and the bitmninous 

 treatment was worn very thin and showed a tendency to crmnble, 

 even on warm days. It is probable that a re- treatment wiU be neces- 

 sary early in the spring as the aggregate of the macadam shows quite 

 generally throughout the central portion of the road. 



Experiment No. 2. — ^This section has a black, leathery mat which 

 is easily marked by the calks of passing horses, but irons out under 

 the wheels so that there is no indication of ''picking up" or dis- 

 integration. In a few places additional gravel had to be spread to 

 prevent bleeding, and it is probable that more top-dressing will be 

 required as soon as hot weather prevails. At the present time very 

 little stone shows in the mat. 



Experimerd No. 3. — The gravel used for top-dressing plainly shows 

 everywhere on this section and an excess still remains along the 

 sides. The mat is a hard, stone-fiUed carpet, practically unbroken, 

 and shows no signs of failure anywhere. In general this was the 

 best appearing section of the road at the time of the inspection. 



