42 BULLETIN 1077, U. S. DEPARTMENT OF AGRICULTURE. 
grade so that there will be no segregated material in the surface of 
the pavement. Exceptionally wet batches should be shoveled from 
the subgrade and wasted on the shoulders. 
FINISHING THE SURFACE. 
After the concrete has been spread approximately to the required 
cross-section, the finishing operations are begun. These operations 
consist of striking-off and tamping the concrete, and finishing the 
surface. Two methods may be employed, viz, hand finishing and 
machine finishing. In hand finishing, each operation must be per- 
formed separately, while in machine finishing all operations can be 
performed simultaneously. Machine finishing is greatly to be pre- 
ferred. 
Hand finishing. — The concrete is first struck off with a strike board 
having from one-fourth to one-half inch more crown than the fin- 
ished crown of the pavement. This allows for a slight amount of 
settlement when the concrete is compacted. The striking off is ac- 
complished by advancing the strike board with a combined longi- 
tudinal and crosswise motion. A slight surplus of concrete should 
always be maintained ahead of the strike board. The tamping 
should be done by means of short, quick, up-and-down strokes of 
the tamper, which should have the same crown as the finished road. 
The best results are obtained by pivoting one end of the tamper on 
the side forms and advancing the other from 2 to 3 feet, at the same 
time tamping the area over which the tamper is advanced. This 
operation is then repeated by pivoting the tamper on the opposite 
form and advancing the end which was first pivoted. As soon as 
possible after the concrete has been tamped it should be rolled with 
a roller having a smooth, even surface and weighing approximately 
three-fourths of a pound per inch of length. The roller should pre- 
ferably be 10 inches in diameter, and 6 feet in length and a long 
handle or ropes may be provided with which to operate it from the 
sides of the pavement. The purpose of rolling is to eliminate slight 
inequalities in the surface and remove the surplus water. After the 
pavement has been rolled the final finish is obtained by means of a 
belt. A 10 or 12 inch canvass or rubber belt is generally used for 
this purpose. The belt should be at least 2 feet longer than the 
width of the pavement and should be provided with wooden handles 
at each end. The first application of the belt should consist of long 
strokes with only a slight longitudinal advance at each stroke. A 
greater longitudinal advance and somewhat shorter stroke should be 
used for the second belting. The final belting should not be done 
until after the water glaze or sheen on the surface disappears. It 
should consist of a rapid longitudinal advance with as short a stroke 
