t ordinary temperature. They are poured into
the joints hot and when they cool are firm enough to comply with the
requirements for a filler. In addition, they have enough ductility to
accommodate the expansion of the pavement due to temperature changes.

=Mastic Fillers.=--Mastic consists of a mixture of about equal volumes
of fine sand and a solid bituminous material. The mixture is prepared
at high temperature and is worked into the joints between the brick
while hot. When cool it resembles the straight bituminous filler
except that the mastic is somewhat more resistant to wear than the
straight bituminous filler.

EXPANSION JOINTS

It is recognized that brick will expand and contract with changes in
temperature. When a bituminous or mastic filler is employed there is
sufficient yield to the filler to accommodate the change in dimension
in the brick, but when the grout filler is used either the expansion
joint must be provided or the pavement must be designed to withstand
the compression due to expansion of the brick. Expansion joints may
consist of a sheet of bituminous mastic prepared for the purpose and
set in place in the pavement. The sheet of joint material is simply
inserted between courses of brick at the proper place.

Another method of forming an expansion joint consists in placing a
strip of wood between courses of brick at the place where a joint is
required. After the pavement has been grouted, the wooden strip is
pulled out and the joint is filled with a suitable bituminous filler.

=Marginal Curb.=--If the sand bedding course is employed, it is
necessary to provide curbing along the sides of the brick to hold the
bedding course in place. The curb is usually constructed integral with
the base and of concrete of the same mixture as the base. The width of
the curb is usually six inches and the top of the curb is at the same
elevation as the edge of brick surface.

CONSTRUCTION OF THE SURFACE

Before the construction of a brick surface should be undertaken on a
road, the drainage should be provided for even more completely than
for a less costly type of surface since it does not pay to jeopardize
the stability of the pavement by failure to provide adequately for the
stability of the supporting soil. Grades should also be reduced to the
economical limit.

The earth subgrade is brought to the proper elevation and cross
section and is thoroughly rolled. If there are places where the soil
will not c