VITRIFIED BEICK PAVEMENTS FOR COUNTRY ROADS. 15 



tively wet after the sprinkling is stopped. All defective brick should 

 of course be replaced by others which meet the requirements of the 

 specifications. 



TRUING THE SURFACE. 



After the pavement has been laid and all defective brick have 

 been replaced to the satisfaction of the engineer, the next step is to 

 sweep the surface clean, and smooth out all inequalities by means of 

 ramming and rolling. The rolling should be done with a power 

 roller weighing from 3 to 5 tons, and the pavement should ordi- 

 narily be rolled in both longitudinal and diagonal directions. The 

 longitudinal rolling should be done first, and should begin at the 

 curbs and progress toward the crown. The roller should pass at 

 least twice over every part of the pavement in each direction. In 

 order to neutralize any tendency which the brick may have to careen 

 under the roller, the number of forward trips over any part of the 

 pavement should equal the number of trips backward over the same 

 part. 



In places where it is impracticable to use the roller for truing the 

 surface — such, for example, as along the curbs or concrete gutters 

 or around manholes — the brick should be brought to a true surface 

 by means of ramming. For this purpose a wooden rammer loaded 

 with lead and weighing from 80 to 100 pounds may be used. The 

 blows of the rammer should not fall directly upon the brick, but 

 should be transmitted through a 2-inch board laid parallel to the 

 curb. 



After the pavement has been trued up, as described above, ' it 

 should be inspected again for broken or otherwise damaged brick, 

 and also for those which have settled excessively, owing to some 

 lack of uniformity in the sand cushion. All defects should be cor- 

 rected, and the areas disturbed in making the corrections should be 

 brought to a true surface by tamping or rolling. 



FILLING THE JOINTS. 



In order to keep the brick in proper position and protect the 

 edges from chipping it is necessary to fill the joints with some suit- 

 able material before the road is opened to traffic. The materials 

 which have in the past been most commonly used for this purpose 

 are sand, various bituminous preparations, and a grout made of equal 

 parts of Portland cement and fine sand mixed with water. 



Sand is the least expensive of these materials, but there are sev- 

 eral 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 



