8 BULLETIN 105, U. S. DEPARTMENT OF AGRICULTURE. 



until they were firmly bedded in the sand cushion. The joints were 

 then filled with a cement grout composed of one part of Portland 

 cement and one part of sand. Table 9 contains the mechanical 

 analysis of the sand used. 



Table 9. — Mechanical analysis of sand for grout. 



Per cent. 



Passing ^-inch, retained on 10-rnesh screen 0. 4 



Passing 10-mesh, retained on 20-mesh screen 1. 5 



Passing 20-mesh, retained on 30-mesh screen 2. 8 



Passing 30-mesh, retained on 40-mesh screen 6. 



Passing 40-mesh, retained on 50-mesh screen 30. 6 



Passing 50-mesh, retained on 80-mesh screen 41. 1 



Passing 80-mesh, retained on 100-mesh screen 4. 1 



Passing 100-mesh, retained on 200-mesh screen 11.-2 



Passing 200-mesh screen 2. 3 



The grout was applied in two courses, the first of which was thin 

 enough to run freely. This was swept into the joints by means of 

 rattan hand brooms. After the first course had settled well into the 

 joints and before any of it had dried, grout of the consistency of thick 

 cream was squeegeed over the pavement, leaving all the joints com- 

 pletely filled . 



Protection of the 'pavement: — Immediately after the completion of 

 the grouting, sand was spread over the pavement to a depth of one- 

 half inch and kept wet for seven days. 



Expansion joints. — No transverse expansion joints were constructed 

 and the ends of the pavement are practically fixed. A longitudinal 

 expansion joint was constructed along each curb line. From station 

 52 + 00 to station 54 + 00 it is 1 inch wide and was filled with a 

 mixture of equal parts, by volume, of coal-tar pitch and Portland 

 cement. From station 54 + 00 to station 56 + 00 the expansion joint 

 is one-half inch wide and is filled with asphaltic felt, while from sta- 

 tion 56 + 00 to station 61+00 the expansion joint is 1 inch wide and 

 is filled with an oil asphalt having a penetration at 25° C. of 3 mm. 

 and a melting point of 94° C. 



Measured hriclcs. — The thickness of a sufficient number of bricks 

 of each variety to lay two courses across the pavement was measured. 

 These bricks were then laid in the same manner as the other brick, 

 and their location was carefully recorded, so that at any future time 

 they may be taken from the pavement, measured, and the amount 

 of wear determined. 



Cost data. — The cost data given in Circular No. 99 were neces- 

 sarily subject to revision when the project was completed. Table 10 

 shows the cost of the entire work by experiments, together with a 

 statement of the unit costs of material and labor prevailing on the. 

 work. . 



