CURB 125 



The Mixing Method. A two-course pavement is the 

 more common in municipal practice and will be briefly 

 described here. On the finished and rolled subgrade is 

 deposited a layer of 1 to 2f to 5 concrete which should 

 be 4 inches thick after tamping. The wearing course 

 may be made of concrete of the proportions one part 

 cement, one part sand and one part J- to ^-inch granite or 

 trap chips. The wearing course should be 2 inches thick. 

 The leveling off of the wearing course is done with a wooden 

 template resting on scantling set true to line and grade. 

 Transverse joints for expansion are made every 25 feet. 



The Grouting Method. The method used by the Has- 

 sam Paving Company will be briefly set forth. On the rolled 

 subgrade is placed a layer of broken stone ranging from 

 1J to 2| inches and rolled down to a thickness of 4 inches. 

 This is grouted with a 1 to 3 grout. The surface layer 

 consists of a 2-inch layer of crushed trap poured with a 

 1 to 2 grout. On the surface layer is thinly spread a thick 

 grout consisting of 1 part cement, 1 part sand and 1 part 

 trap screenings the size of a pea. This is broomed into 

 the surface with stiff brooms. The Long Island Motor 

 Parkway pavement was constructed by the Hassam method. 



Concrete pavements are apt to be slippery in winter. 

 To prevent this they have been covered with a bituminous 

 coat in which is incorporated small trap rock chips. 



Curb. Curb may be of bluestone, sandstone, granite 

 or concrete. In order to preserve the alignment of a stone 

 curb a concrete foundation is used, the sand foundation 

 having become practically obsolete. The setting of the 

 curb should take place before the pavement is constructed. 



Straight curb should be carefully aligned. It is the cus- 

 tom to set a piece of curb every 25 feet by aid of the engi- 

 neer's measurements and then stretch a mason's line 



