DRAINAGE METHODS FOR COUNTY ROADS. 85 
be broken off as the wedging proceeds. When this process is completed the 
foundation shall present a true and uniform appearance and shall contain no 
stones that may be loosened or shaken with the hand or foot. 
After the foundation has been wedged and surfaced as above provided it 
shall be thoroughly rolled with a roller weighing not less than 10 tons. Any 
depression that may develop under the roller shall be corrected by taking up 
and resetting the affected portion, and the portion thus reset shall be again 
rolled. When the rolling is finished the foundation shall be uniformly of the 
required grade and cross section and every stone which it contains shall be 
firmly wedged in place, and the surface shall be free from all loose stone or 
other material which would be objectionable in the road crust. 
CONCRETE FOUNDATION. 
Upon the subgrade prepared as herein specified shall be laid a concrete foun- 
dation of the width and thickness shown on the plans. The subgrade shall be 
wet but not muddy when the concrete is placed upon it. The concrete shall be 
composed of the following materials, by volume : One part cement, 3 parts sand, 
and 5 parts of gravel, crushed stone, or crushed slag, and sufficient water to 
form a quaky mass, and shall be thoroughly mixed in a machine mixer of the 
batch type, so constructed and operated that the thorough mixing of the ma- 
terials will be assured. The concrete shall be so delivered to its place on the 
subgrade as not to cause or permit any separation of the materials. Wheel- 
barrows or other devices used for measuring the materials shall be of uniform 
capacity. The concrete shall be deposited in place immediately after it is mixed 
and shall be well compacted as fast as it is placed. The top surface shall be 
smoothed by troweling with shovels or by some other means approved by the 
engineer, and when completed shall not vary more than one-half inch from the 
proper shape and grade, as shown on the plans and profiles. The concrete foun- 
dation shall be kept wet by sprinkling with water during the first four days 
after it is laid. No hauling over it or rolling or tamping of brick upon it will 
be permitted for seven days after it is placed, and during this time it shall be 
properly protected from injury. Concrete shall not be mixed when the tem- 
perature of any of the materials is less than 35° Fahrenheit. Concrete shall not 
be used after it has begun to show evidence of setting, and no concrete which has 
once set shall be used as material for mixing a new batch. 
FLANGE CURBS. 
Concrete curbs shall be built on the foundation as shown on the plans. The 
concrete shall be composed of the following materials, by volume : One part of 
cement, li parts of sand, 3 parts of gravel or crushed stone, and water. The 
materials shall be thoroughly mixed in a machine mixer of the batch type or 
by hand. If the mixing is done by hand, it shall be done upon a water-tight 
platform with raised edges, in the following manner : The sand and cement shall 
be thoroughly mixed dry and spread out upon the mixing platform, and upon 
this dry mixture shall be spread the coarse aggregate. Water shall then be 
poured over the aggregate in such an amount that the resultant concrete will 
be of a quaky consistency. The whole mass shall then be turned with shovels 
until all of the materials are thoroughly mixed. The concrete for the curb 
shall be placed upon the foundation before the concrete of either the curb or 
the foundation has taken its initial set. and care shall be taken, such as rough- 
