﻿VITRIFIED BRICK AS MATERIAL FOR COUNTRY ROADS. 27 



method its melting point shall be not less than 90° C. and not greater 

 than 110° C. The penetration at 0° C. of a No. 2 needle acting one 

 minute under a weight of 200 grams shall be not less than 2 milli- 

 meters. The penetration at 46° C. of a No. 2 needle acting five sec- 

 onds under a weight of 50 grams shall not exceed 10 millimeters. 1 



When grouting, care shall be exercised to prevent the grout from 

 covering and setting up over this cushion'. 



CONCLUSION. 



Before concluding this discussion of brick pavements, it would 

 seem desirable to emphasize the importance of proper engineering 

 supervision. In the past many communities have expended large 

 sums in efforts to improve their public highways without first having 

 secured the services of some one competent to plan and direct the 

 work. The results have usually been very unsatisfactory under 

 such circumstances and have frequently served to discourage further 

 effort. One of the mistakes most commonly observed consists in 

 constructing some expensive type of pavement on a road where the 

 location is faulty or the grades are impracticable. Not infrequently 

 sharp angles in the alignment or abrupt changes in the grade, which 

 might be easily and inexpensively remedied by an experienced 

 engineer, are left to impede traffic throughout the life of a costly 

 and perhaps durable pavement. 



Even in constructing common earth roads it is doubtful economy 

 to dispense with the services of a competent engineer, and if any 

 considerable quantity of work is to be done, such services should 

 certainly be secured. Since brick pavements are probably more 

 expensive to construct than any other type of pavement at present 

 used for country roads, it is all the more important that their con- 

 struction should be carefully planned and well executed. 



i Instead of making a poured joint, as above described, the cushion may be constructed of some of the 

 specially prepared expansion-joint materials. These consist of thin, flexible boards, built up by successive 

 layers of felt and, a soft bituminous material. They can be obtained with a width approximately the 

 depth of a brick, and a sufficient number of them to make the proper thickness of cushion are set on edge 

 along the curb when the brick are laid. 



