PORTLAND CEMENT CONCRETE PAVEMENTS. 27 
Dimensions of pavements, length of haul for materials, and cost of cement and 
amount used per square yard. 
Project No. 1 : 
Area of pavement laid square yards__ 5, 000 
Thickness of pavement inches — 6 
Width of pavement feet — 45 
Length of haul for materials . mile — § 
Cost of cement per barrel dollars — 1. 0G 
Amount of cement used per square yard barrel— . 29 
This is a one-course pavement for which the coarse aggregate was gravel 
mixed with a small amount of Joliet crushed stone. The conditions under 
which the pavement was constructed appear to have been favorable. The cost 
is low. 
Project No. 2 : 
Area of pavement laid square yards 7, 111 
Thickness of pavement inches 6| 
Width of pavement feet__ 16 
Length of haul for materials miles — 1-| 
Cost of cement per barrel dollar . 98 
Amount of cement used per square yard - barrel-. . 33 
This is a one-course pavement. The sand and crushed stone were both 
obtained free and the only charges were for freight. A newly filled sewer 
trench made it necessary to cross-reinforce a small part of the pavement 
with 1-inch square twisted bars, 6 feet long and 12 inches center to center. 
The cost of this section, exclusive of grading, was only $0.7336 per square yard. 
This low cost was largely due to the free sand and crushed stone. 
Project No. 3 : 
Area of pavement laid square yards— 5, 594 
Thickness of pavement inches 7 
Width of pavement feet 18 
Length of haul for materials , mile | 
Cost of cement per barrel dollars— 1. 025 
Amount of cement used per square yard barrel . 29 
This is a one-course pavement, and the coarse aggregate consisted of gravel. 
Armored expansion joints were used. The thickness varies from 8 inches at 
the center to 6 inches at the side. Congestion of traffic caused some expense 
and delay. The cost, however, is only moderate. 
MAINTENANCE. 
The shoulders, slopes, and drainage structures of concrete roads 
require the same kind of maintenance as other types of improved 
roads and will, therefore, not be given special attention here. The 
maintenance of the pavement consists, for the most part, in repairing 
cup holes, cracks, contraction joints, and perhaps the renewal of an 
occasional defective area. 
Cup holes are spots in the surface of the pavement which break 
down under traffic and which may result from any one of a number 
of causes. The most frequent cause for such defects is the presence 
