18 BL X LLETIX 373, U. S. DEPARTMENT OF AGRICULTURE. 
Sand is the least expensive of these materials, but there are 
several very serious objections to its use as a joint filler: (1) It does 
not protect the edges of the brick; (2) it is easily disturbed in clean- 
ing the pavement and is likely to be washed out by rain on steep 
grades; (3) it does not entirely prevent water from penetrating 
through to the foundation: and (4) it does not bond the individual- 
brick together and so enable them to present a concerted resistance 
to traffic. 
The bituminous fillers vary considerably in quality and efficiency, 
but all are more or less unsatisfactory. One of the principal objec- 
tions to their use is based on their tendency to run out of the joints 
into the gutters during warm weather and to crack and spall out 
during cold weather. This tendency can. of course, be partially over- 
come by exercising proper care in selecting the materials. It should 
also be noted in their favor that brick pavements, the joints of which 
have been filled with bituminous preparations, are ordinarily less 
noisy than those in which a Portland cement grout filler has been 
used. The grout filler is unquestionably very much superior from 
a standpoint of durability, however, and the excessive noise under 
traffic which has been frequently observed in connection with its 
use can be largely eliminated by the use of proper bituminous ex- 
pansion cushions along the curbs. It is, therefore, recommended as 
better adapted for filling the joints in brick pavements than any 
other material which has been commonly used for that purpose. 
"When the joints of a brick pavement are properly filled with 
Portland cement grout the individual brick are firmly bonded to- 
gether and. since the material composing the joints scarcely wears 
more rapidly than the brick, the edges of the brick are well pro- 
tected. 
When the pavement is constructed on a foundation other than con- 
crete the advantages of using the grout filler are especially evident 
because of the protection thus afforded the foundation. 
A satisfactory method for mixing and applying the grout filler 
by hand may be described as follows: Grout boxes, constructed 
in such manner that when resting on a level platform one corner 
will be lower than the others, should first be provided. A suitable 
design for such boxes is shown in Plate III. The number of boxes 
required depends on the width of the pavement : ordinarily one 
box to each 10 feet of width will be found sufficient. The grout, 
which should be put on in two applications, is prepared in batches 
each of which consist of a quantity of cement not exceeding one sack, 
a like amount of fine, clean sand, and water. The sand and cement 
should first be thoroughly mixed dry and sufficient water then added 
to produce a liquid mixture. The consistency of the mixture for the 
first application should be approximately the same as that of ordi- 
