DRAINAGE METHODS FOE COUNTY ROADS. 



21 



together 1 part cement, 2 parts sand, and sufficient water to give the grout a 

 consistency about equal to that of ordinary cream. When the joints are grouted, 

 the bedding sand should not extend above the center of any stone ; because, if 

 it does, the grout is very likely to crack and spall out. 



This type of construction will give a gutter practically as strong 

 as the road surface and may consequently b3 used in juxtaposition to 



COBBLESTONE GUTTER 



D=^ Cross-secfion is segment of a circle. 



Use cobblestone 4" to 6" 

 Sand bedding about E" thick 



Fig. 4. 



it. If there is little probability that traffic will use a gutter, naturally 

 such heavj' construction is not necessary. There are cases when ade- 

 quate gutters may be built on a thin course of cinders with a sand 

 bedding course. If the soil be not noticeably poor, 4 inches of cinders 

 or gravel will be adequate. In sojne cases, on unusually favorable 

 soils, such as sands or sandy loams, it may be possible to build im- 

 mediately on the soil in place or with nothing more than the sand 

 bedding course added. 



CONCRETE GUTTER 



ROADWAY 



D=g Cross-section is segment of a circle. 



]-ZA concrete about 6" thick 



Foundation of gravel, broken stone.or good quality earth. 



Fig. 5. 



Figure 4 shows a typical cross section for a cobble gutter, and 

 Plate I is a photograph showing a completed gutter which was con- 

 structed in accordance with the foregoing directions and which is 

 now giving satisfactory service. Sand was used for filling the joints 

 in this gutter. 



CONCRETE GUTTERS. 



There are two types of concrete gutters in general use. One has 

 a curved cross section, as shown in figure 5, and the other is essen- 



