I4S 



EXPERIMENTS IN ROAD SURFACING 



that had been graded two years before, and it has been 

 described in detail on pages 60-63 of Bulletin 46. It may be 

 recalled that the earth fill forming the upper foot of grade of 

 this road was largely clay and a clayey hardpan, thoroughly 

 drained for most of the distance by a rock fill underneath. 

 The road was divided longitudinally into sections of fifty feet 

 each except that several sections were shortened (see plan) 

 because sufficient surfacing material of certain kinds was not 

 available for full lengths. The following table shows in detail 

 what was done upon each section : 



1 



2 



3 



4 



5 



6a 



6b 



7 



8a 



8b 



9 

 10 

 11 

 12 

 13 

 14 

 15 



30 

 45 

 50 

 50 

 50 

 15 

 35 

 50 

 10 

 40 

 50 

 13 

 24 

 13 

 50 

 50 

 50 



3. 



5. 

 4. 

 5. 



5. 



0.5 

 1.5 



3.5 



5. 



2.5 



10. 

 8. 

 2. 

 4. 

 2. 



8. 



0. 

 2. 

 4. 

 6. 



G. Chesley gravel, screened. 

 G. Chesley gravel. 

 ; Lee gravel. 

 Reservoir screened gravel. 



Reservoir gravel. 



Clay. 



Coarse reservoir sand. 



Coarse reservoir sand. 

 Lee gravel, screened. 



Coarse sand, rolled. 



Section macadamized with Lee gravel, 

 screened, sorted, and rolled. 



Lee gravel, screened and sorted. 

 Point rock mixed with earth. 

 Point gravel. 

 Point beach rock. 



E. Emerson gravel. 



Nothing for one year. 

 E. Emerson gravel, 2d year. 

 Stones 2 to 6 inches through. 

 Screened reservoir gravel. 



DESCRIPTION OF MATERIAL USED 



• The G. Chesley gravel is a loose, silicious, water-worn 

 material, witli no clay admixture, containing very few stones 



