16 BULLETIN 23. U. S. DEPARTMENT OE AGRICULTURE. 
during cold weather. This tendency can. of course, be partially 
overcome 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 at first than those in which a Portland cement grout filler 
has been used. The grout filler is unquestionably very much supe- 
rior 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 
expansion 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 together 
and the pavement is thereby practically converted into a monolith. 
Moreover, since the material composing the joints scarcely wears 
more rapidly than the brick, the edges of the brick are well protected, 
and the importance of this feature has already been pointed out. 
The most satisfactory method yet devised for mixing and applying 
the grout filler 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 II. 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 consists of a quantity of cement not exceeding one sack, a like 
amoimt of fine, clean sand, and water. The sand and cement should 
first be thoroughly mixed dry and siifficient water then admixed 
to produce a liquid mixture. The consistency of the mixture for 
the first application should be approximately the same as that of thin 
cream, and for the second application it should be somewhat thicker. 
The pavement should be cleaned and thoroughly sprinkled as a 
preliminary to making the first application of grout, and it should 
be kept moist by gentle sprinkling while this application is being 
made. The grout should be removed from the boxes and spread 
upon the pavement by means of scoop shovels, and it should be 
immediately swept into the joints. 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 made by clamp- 
ing 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 shovelful is removed, otherwise a separation of 
the -and and cement will almost certainlv occur. 
