18 BULLETIN 373, U. S. DEPAETMENT OF AGEIGLTLTUEE. 



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 frecjuently 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. 



Wlien 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 

 hj 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- 



