DEAINAGE 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. 



EOLLING. 



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 CTJEBS. 



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, 1^ 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- 



