VITRIFIED BRICK PAVEMENTS FOR COUNTRY ROADS. 17 
be kept moist by gentle sprinkling while this application is being 
made. The grout should be swept into the joints immediately after 
it is removed from the boxes and spread upon the pavement. For 
this purpose a coarse rattan or fiber push broom should be used in the 
first application and a squeegee in the second application. The 
squeegee is usually made by clamping a piece of four-ply rubber 
belting or some other similar material, about 6 by 20 inches in size, 
between two pieces of board and attaching a suitable handle. The 
grout in the boxes should be continually stirred until the last of it 
is removed, otherwise a separation of the sand and cement will almost 
certainly occur. 
The first application should proceed about 50 feet in advance of the 
second. Usually both applications are made by the same crew of 
laborers. They simply turn back after having covered the allowable 
distance with the first application and, mixing the grout in the same 
boxes, bring up the second application. The second application of 
grout should completely fill the joints flush with the top of the brick. 
. After the joints are filled as described above and the grout has 
taken its initial set, the entire surface should be covered to a depth 
of approximately 1 inch with sand or fine earth. This is done to 
protect the pavement from the weather and to keep it in a moist 
condition while the grout is hardening. If necessary, in order to 
keep the covering moist, it should be occasionally sprinkled for 
several days after it is spread. 
The covering should be permitted to remain on the surface for 
at least 10 days, and during this period the pavement should be 
kept entirely closed to traffic. If the weather is unfavorable, the 
length of time during which traffic is kept off the road should be 
increased. 
EXPANSION CUSHIONS. 
It has been customary in the past to provide both longitudinal and 
transverse bituminous expansion cushions in grout-filled brick pave- 
ments, but recent practice has demonstrated that the transverse 
cushions may be advantageously omitted if proper longitudinal 
cushions are provided. The principal objection to the use of trans- 
verse expansion cushions is based on the fact that the material com- 
posing the cushions frequently softens during warm weather and 
runs out toward the curb, thus leaving the edges of the adjoining 
brick exposed to destructive impact from the wheels of passing 
vehicles. Even if the cushion consists of a material which does not 
run in warm weather, it is necessarily softer than the brick, and the 
natural result is still the development of unevenness in its immediate 
vicinity. No such objection can exist concerning longitudinal ex- 
pansion cushions, however, if they are placed adjacent to the curbs 
92742°— 15 3 
