VITRIFIED BRICK AS MATERIAL FOR COUNTRY ROADS. 25 
which are soft, badly spalled, misshapen, or otherwise defective^hall 
be-removed and replaced with perfect brick. Kiln-marked bricfe%iay 
be turned over, and if the reverse edge is smooth and no other f emit is 
found, they may remain in the pavement. ^ 
The above provision for correcting defects shall not be understood 
to relieve the contractor from exercising every reasonable precaution 
to see that only satisfactory brick are correctly placed in the pave- 
ment when it is first laid. 
After the brick have been laid and inspected as above provided, 
they shall be brought to a true surface by means of rolling and tamping. 
The rolling shall be done with a power roller weighing not less than 
3 tons nor more than 5 tons and the pavement shall be rolled in both 
longitudinal and transverse directions. The longitudinal rolling 
shall begin at the curbs and progress toward the center. The roller 
shall in all cases cover exactly the same area in making its backward 
trip which was covered in its forward trip, and shall proceed at a very 
slow rate until the entire pavement has received the first rolling. 
The longitudinal rolling shall continue until the brick have been 
brought to a true surface and are firmly embedded in the sand 
cushion. The pavement shall then be thoroughly rolled transversely 
at an angle of 45 degrees with the curb in both directions. Careful 
inspections shall be made after both the longitudinal and transverse 
rollings, and all broken or otherwise injured brick shall be removed 
and replaced to the satisfaction of the engineer. 
The brick next to the curb and at other points not readily accessible 
to the roller shall be brought to a true surface by means of ramming 
with a hand rammer made of wood and loaded to weigh not less than 
80 pounds. The blows of the rammer shall be transmitted through a 
2-inch board not less than 5 feet long. 
Filling the joints. — The filler shall consist of a grout composed of 
equal parts of Portland cement and sand, and shall be applied in 
two coats. The cement shall conform to the specifications herein- 
before given for Portland cement. The sand shall also conform to 
the specification contained herein for sand to be used in concrete, 
except that the largest grains shall be required to pass a J-inch mesh 
screen instead of a ^-inch mesh screen. 
The grout shall be mixed in small batches and not more than one 
sack of cement to one batch shall be mixed at any one time. The 
sand and cement shall be thoroughly mixed dry until the mass assumes 
an even shade of color. Sufficient clean water shall then be admixed 
to produce a consistency about equal to that of thin cream for the 
first application, and slightly thicker for the second application. 
The materials shall be mixed in suitable boxes, which have been 
approved by the engineer. The legs of each box shall have different 
lengths, so that the mixture will readily flow to the lowest corner of 
