64 



BULLETIN 407, U. S. DEPARTMENT OF AGRICULTURE. 



the half along the gutter was muddy and showed a tendency to 

 disintegrate. A line of potholes existed along the middle. Much 

 patching will be required as soon as weather permits. In a few 

 places the road metal is raveling and the winter calks on the horses' 

 shoes have cut entirely through the mat on the east side of the road. 

 It appears from a few breaks just forming at the time of inspection 

 that it is this cutting of the mat which starts the numerous pot- 

 holes. The cost of this re-treatment is shown in Table 64. 



Table 64. — Materials and cost data for surface re-treatments. 









Quantity of 



















3 

 a* 



material per 





Cost per square yard (cents). 







Bituminous material. 



square yard. 















6 



'''it 



3 



3^ 





3«* 











a 



n 





a 





>HH 



q , . 



ii-a 



OTJ 



.9 C 







M 



■" o 



qS 



'M 





1 





03 



u 



III 



1- 



03 







03 



u 



1 



1 



7; a -2 



P4 





1 



m 





■< 



5 



o 



w 



M 



o 



m 



o 



<^ 



<< 



m 



H 



9 



Asphaltic petroleum, cold 































761 

 1,013 



0.197 

 .172 





0.016 

 .016 



2.6 

 2.4 



(1) 

 (1) 



3.6 

 3.6 



0.1 

 .2 



0.4 



.6 



0.4 

 .5 



0.4 

 .5 



7.5 



in 



do 



7.8 









1 Not ascertained. 

 MAINTENANCE DURING 1915. 



In addition to the general re-treatments above described, the patrol 

 system of maintenance was continued during the year. Table 65 

 presents the total cost of this maintenance and the re-treatments, 

 together with the total cost of each experiment to December 31, 1915. 



Table 65. — Costs of construction and of surface mainteannce to December SI, 1915, of 

 1911 experiments at Chevy Chase, Md. 





Date 

 com- 

 pleted. 



Area. 



Maintenance cost of experiment. 



Construction per square 

 yard (cents). 



Experiment No. 



To 1913. 



19141 



1915 



Total. 



Con- 

 struc- 

 tion. 



Mainte- 

 nance. 



Total. 



1 



1911. 

 Oct. 31 

 ...do 



Sq. yds. 



1,581 



705 



1,555 



1,555 



1,447 



1,555 



131 



848 



1,477 

 761 



1,013 

 377 



SO. 00 



.00 



.00 



4.05 



262. 57 



3.47 



1.43 



67.88 



80.64 



39.65 



19.05 



.00 



S91.48 

 .00 

 .00 



2.54 

 .90 

 .00 

 .45 



1.33 



.00 



44.86 



286.62 



.00 



S36.97 

 16.14 

 14.71 

 40.18 

 42.03 

 32.15 

 4.70 

 24.50 



50.16 



63.71 



132. 17 



.00 



S128.45 

 16.14 

 14.71 

 46.77 

 305. 50 

 35.62 

 6.58 

 93.71 



130. 80 



148. 22 



437.84 



.00 



46.18 

 64.42 

 64.69 

 57.18 

 58.27 

 68.22 

 59.96 

 54.80 



2 39.59 

 42.01 

 44.31 

 81.51 



8.12 



2.29 



.95 



3.00 



21.11 

 2.29 

 5.02 



11.05 



8.86 



19.48 



43.22 



.00 



54 30 



2.... 



66 71 



3 



Nov. 18 

 Nov. 8 

 Dec. 2 

 Nov. 23 

 Dec. 5 

 ...do 



65 64 



4.... 



60 18 



5 



79 38 



6.... 



70 51 



7a 



64 98 



7b 



65 85 



8 



1912. 

 Aug. 24 

 June 4 

 Nov. 22 

 Dec. 16 



48.45 



9 



61 49 



10.... 



87 53 



11 



81 51 







1 Differences between these quantities and those appearing in Table 25, page 34, U. S. Dept. Agr. Bul- 

 letin 257, are due to a distribution of " General expenses," not made in the earlier table. 



2 The construction costs here shown for sections 8, 9, and 10 are uniformly 32.58 cents higher than those 

 appearing in the original table of costs on page 9 of Circular No. 99. The amount represents the cost of the 

 2-inch top course of water-bound macadam, and it is added here in order to mate the costs of the wearing 

 courses of these sections comparable with the costs of penetration and mixed surfaces on other sections. 



