PORTLAND CEMENT CONCRETE PAVEMENTS. 10 
METHODS, ORGANIZATION, AND EQUIPMENT. 
When it is considered that ordinarily from one-third to one-half 
of the total cost of constructing a concrete pavement is for the labor 
employed in doing the work after the materials are delivered, the 
importance of efficient organization, proper equipment, and eco- 
nomical methods becomes readily apparent. Failure to give these 
features proper consideration may easily result in adding from 10 
to 20 per cent to the cost of a concrete pavement, and has no doubt 
frequently caused road contractors to sustain a net loss on projects 
of this kind, where profits might have been made. 
It is not the province of this bulletin to furnish detailed rules for 
the guidance of contractors in planning and executing their work, 
but it seems desirable to discuss briefly a few important points which 
contractors and engineers in charge of force-account work should 
consider in connection with concrete-pavement construction. The 
points which are of most importance, and to which the discussion 
will be confined, are concerned with, first, the proper order and 
progress of the work; second, the economic handling of materials; 
and third, the amount of capital necessary to carry on such work 
economically. 
ORDER AND PROGRESS OF THE WORK. 
In constructing a concrete pavement it is especially desirable that 
the work of mixing and placing the concrete be as nearly continuous 
as practicable after it is once begun. Where the mixer is permitted 
to stand idle for even a few days the force of laborers employed in 
operating it will usually become more or less disorganized, and an 
appreciable amount of loss and unsatisfactory work will generally 
result when the mixing is resumed. On this account the order and 
progress of the work should ordinarily be planned with the primary 
view to keeping the mixer going full time every working day that 
the weather will permit. This means that ample provision should 
be made for completing the drainage structures, the grading, and 
the preparation of the subgrade well ahead of the mixer, as well as 
for supplying the mixer with all necessary materials. 
The drainage structures should preferably be completed in ad- 
vance of the grading in order to obviate the necessity for moving 
embankment material the second time. Where the concrete mate- 
rials are to be hauled out by means of an industrial railway, how- 
ever, it is usually impracticable to extend the railway ahead of the 
grading, and the saving effected in hauling the materials for the 
drainage structures on the industrial railway may justify permitting 
the grading to proceed ahead of the drainage structures. 
