VITRIFIED BRICK PAVEMENTS FOR COUNTRY ROADS. 23 
Embankments shall be formed of good, sound earth and carried up full width. 
The earth shall be deposited in layers not more than one (1) foot in thickness, 
and each layer shall be rolled until thoroughly compacted with a roller weigh- 
ing not less than ten (10) tons. All existing slopes and surfaces of embank- 
ments shall be plowed or scarified where additional fill is to be made, in order 
that the old and new material may bond together. When sufficient material 
is not available within the fence lines to complete the embankments, suitable 
borrow pits, from which the contractor must obtain the necessary material, 
will be designated by the engineer. If there is more material taken from the 
cuts than is required to construct the embankments as shown on the plans, the 
excess material shall be used in uniformly widening the embankments or shall 
be deposited where the engineer may direct. Where embankments are formed 
of stone the material shall be carefully placed, so that all large stones shall be 
well distributed and the interstices shall be completely filled with smaller stone, 
earth, sand, or gravel, so as to form a solid embankment. 
During the work of grading, the sides of the road shall be kept lower than the 
center and the surface maintained in condition for adequate drainage. 
The grading of any portion of the road shall be complete before any surfacing 
material is placed on that portion ; and where the plans do not call for any sub- 
stantial change in the grade of any existing section of the road the surface shall 
be completely scarified to a depth of three (3) inches or more before the sub- 
grade is prepared. 
SUBGRADE. 
The subgrade, or that portion of the road upon which the base for the brick 
roadway is to be laid, shall consist of good, sound earth brought to the proper 
elevation, alignment, and cross section, and shall be rolled until firm and hard. 
The rolling shall be done with a roller of the macadam type, weighing not less 
than ten (10) tons and not more than fifteen (15) tons. Should earth be en- 
countered which will not compact by rolling, so as to be firm and hard, it shall 
be removed and suitable material put in its place, and that portion of the sub- 
grade shall be again rolled. When the rolling is completed the surface of the 
subgrade shall conform to the cross section shown on the plans, and shall have 
the proper elevation and alignment, and shall be so maintained until the con- 
crete base is in place. 
MATERIALS. 
Cement. — The cement for use in this work shall meet the requirements of the 
United States Government specifications for Portland cement as published in 
Circular No. 33, United States Bureau of Standards, issued May 1, 1912. 
All cement shall be held at least ten (10) days after sampling before it is used 
in any part of the work. If the cement satisfactorily passes all tests that may 
be made within that time, it may be used and the twenty-eight (28) day test 
will not be insisted upon; but if it should fail to pass satisfactorily any test 
made within that time, then the cement shall not be used until it has satis- 
factorily passed all tests, including the twenty-eight (28) day test. All cement 
shall be delivered on the work in cloth or paper bags, containing ninety-four 
(94) pounds, net weight, and this amount of cement shall be considered as 
having a volume of one (1) cubic foot. In order to allow ample time for in- 
specting and testing, the cement shall be stored in a suitable weather-tight 
building, having the floor blocked or raised from the ground, and shall be so 
stored as to permit of easy access for inspection, and so that each carload ship- 
ment may be readily identified. 
