90 STANDARD SPECIFICATIONS 



work will depend upon the richness or the leanness of the mixture 

 and the character of the aggregates. 



The structural value of such concretes shall be based upon 

 the average compressive strength in 28 days, as determined above 

 for normal concrete. (Par. 375.) 



377. Cement Mortar. Cement mortar, used in reinforced 

 concrete work, shall generally be composed of 1 part Portland 

 cement and from 2 to 3 parts of fine aggregates. The mortar 

 shall be mixed by hand. (Par. 330.) 



378. Cement Grout. Cement grout, used in reinforced 

 concrete work, shall be composed of neat Portland cement mixed 

 with water to a consistency of thick cream or whitewash. 



379. Workmanship: 



(a) All material and labor shall be of the best quality in every 

 respect and shall be subject to inspection and approval 

 at any time during the progress of the work. 



(6) The entire work shall be constructed in a substantial 

 and workmanlike manner, and to the satisfaction and 

 acceptance of the Engineer. (Par. 383.) 



(c) The contractor shall employ skilled or suitable mechanics 

 and laborers for every kind of work and shall, at the 

 request of the Engineer, discharge any workman whom 

 he deems incompetent, negligent, or untrustworthy. 



380. Facing. (See Par. 318.) 



381. Finishing: 



(a) The finishing of the surface shall be determined before 

 the concrete is placed and the work conducted so as 

 to make possible the finish desired. 



(6) After the forms are removed any small cavities or open- 

 ings in the face shall be neatly filled with cement mortar, 

 if necessary in the opinion of the Engineer. Any 

 ridges due to cracks or joints in the lumber shall be 

 rubbed down with chisel or wooden float. 



(c) When desired the face may be covered with a finish of a 



thin grout, or a whitewash, applied with a brush. 

 Plastering shall not be applied to any face exposed to 

 the weather. 



(d) Before the concrete has thoroughly set the face may be 



treated with a wire brush; after having hardened with 

 a soft brick, with hand or pneumatic tools. 



