﻿24 BULLETIN 23, U. S. DEPARTMENT OP AGRICULTURE. 



than 300 pounds. When finished it shall present a smooth, uniform 

 appearance. 



The brick. — The brick shall be delivered upon the road and neatly 

 piled outside of the curb lines at such points as are approved by the 

 engineer before the grading is started. The loading, hauling, and 

 unloading shall be carefully done, and at no time shall the brick be 

 thrown, dumped, or in any way roughly handled. 



All brick used in the pavement shall be thoroughly vitrified, regular 

 in shape and size, evenly burned, and first class in all other respects. 

 The dimensions shall be 3 J inches in width, 4 inches in depth, and 

 8 J inches in length, and any brick varying from these dimensions 

 by more than one-half inch in length or by more than one-eighth 

 inch in width or depth shall be rejected. If the edges are rounded, 

 the radius of the curve shall not exceed one-eighth inch. Each brick 

 shall have projections on one side, formed during the process of 

 manufacture, which will serve to produce joints not exceeding one- 

 fourth inch in width and not less than one-eighth inch, when the 

 brick are placed in the pavement. 



No brick shall be used in which representative specimens, when 

 subjected to the rattler test recommended by the subcommittee on 

 paving brick of the American Society for Testing Materials 1 lose 

 more than 22 per cent of the original weight of the dried brick com- 

 posing the charge. In making this test 10 representative bricks shall 

 constitute a charge and, in weighing the rattled brick, no part of a 

 brick weighing less than 1 pound shall be included. 



The modulus of rupture for any one representative brick shall not 

 be less than 2,400, and the average modulus of rupture for all bricks 

 tested shall not be less than 2,600. If this test is employed, at least 

 five bricks shall be tested. 



Any carload of brick more than 10 per cent of which fails to con- 

 form to any of the above requirements shall be rejected. If not more 

 than 10 per cent of a carload fails to meet the requirements, the 

 defective bricks may be picked out and the remainder of the carload 

 used. 



Laying the brick. — The brick shall preferably be carried to the 

 pavers on pallets or in clamps and not wheeled in barrows. They 

 shall be laid in straight courses at right angles to the line of the pave- 

 ment, and if a variation in alignment of more than one one-hundred- 

 and-twentieth the width of the pavement occurs, it shall be corrected 

 by taking up and relaying affected courses. 



No parts of brick shall be employed in the pavement except at the 

 beginning and ending of the courses or at other closures. All brick 

 shall be laid with the best edge exposed and as close as possible. 

 After the brick are laid, they shall be carefully inspected and all those 



1 The complete specifications for making this test are given as an appendix to this bulletin. 



