SPECIFICATIONS FOR PORTLAND CEMENT. 617 



Engineer Corps, U. S. Army, 1902. 



(1) The cement shall be an American Portland, dry and free from 

 lumps. By a Portland cement is meant the product obtained from 

 the heating or calcining up to incipient fusion of intimate mixtures, 

 cither natural or artificial, or argillaceous with calcareous substances, 

 ihe calcined product to contain at least 1.7 times as much of lime, by 

 weight, as of the materials which give the lime its hydraulic proper- 

 ties, and to be finely pulverized after said calcination, and thereafter 

 additions or substitutions for the purpose only of regulating certain 

 properties of technical importance to be allowable to not exceeding 

 2 per cent of the calcined product. 



(2) The cement shall be put up in strong, sound barrels well lined 

 with paper, so as to be reasonably protected against moisture, or in 

 stout cloth or canvas sacks. Each package shall be plainly labeled 

 with the name of the brand and of the manufacturer. Any package 

 broken or containing damaged cement may be rejected or accepted 

 as a fractional package, at the option of the United States agent in 

 local charge. 



(3) Bidders will state the brand of cement which they propose to 

 furnish. The right is reserved to reject a tender for any brand which 

 has not established itself as a high-grade Portland cement and has not 

 for three years or more given satisfaction in use under climatic or other 

 conditions of exposure of at least equal severity to those of the work 

 proposed. 



(4) Tenders will be received only from manufacturers or their author- 

 ized agents. 



(The following paragraph will be substituted for paragraphs 3 and 4 

 above when cement is to be furnished and placed by the contractor: 



No cement will be allowed to be used except established brands of 

 high-grade Portland cement which have been made by the same mill 

 and in successful use under similar climatic conditions to those of the 

 proposed work for at least three years.) 



(5) The average weight per barrel shall not be less than 375 Ibs. net. 

 Four sacks shall contain one barrel of cement. If the weight as deter- 

 mined by test weighings is found to be below 375 Ibs. per barrel, the 

 cement may be rejected, or, at the option of the engineer officer in 

 charge, the contractor may be required to supply, free of cost to the 

 United States, an additional amount of cement equal to the short- 



