fOEK 



Specifications 



The specifications under which the eementa intended for use on 

 :l l imp mbmitted, were, from 1896 to 189 



Portland cement must be of the best quality and of such fine- 



of the cement will pass through a Bieve of 2500 



a to the Bquaxe inch, and 9(# through a sieve of 10,000 



[uare inch. Portland cement when mixed neat 



e day in air and Bix days in water, shall with- 



Itrain of not less than 400 lb to the square inch; 



and when mixed in the ratio of 3 lb clean, sharp sand to 1 lb 



of cement, and exposed one day in air and six days in water, it 



shall withstand a tensile strain of not less than 125 lb per square 



a. 



Natural hydraulic cement must be of the best quality, and of 



such fi - that 90* will pass through a sieve of 2500 meshes 



to the square inch, and S0# through a sieve of 10, (00 meshes to th.3 



square inch. Briquets, made of equal parts of natural hydraulic 



t and crushed quartz, immersed in water as soon as they 



iicitiitly hard to sustain a ^V i nca v:1Ye weighted with 



1 lb, must show a tensile strength of 65 lb to the square inch at 



the expiration of seven days; but briquets showing less than such 



strength will be held until 28 days have elapsed, when, if they 



then -how such strength as to sustain as many pounds to the square 



inch above 1* en day test shows them to have fallen 



65, they will be deemed to Lave passed this test. 



ta made of neat cement must not set so as to support a 

 i 1 * inch wire with a load of J lb in less than 15 minutes. Briquets 

 of neat cement must not show checks or cracks when immersed 

 in wal en days after mixing. 



Portland and natural cements manufactured in this state will 

 ference for this work, provided they satisfactorily 

 died for by these specifications. 



Th< 08 at present in use are the following. 



Requirements hydraulic cement. American Portland cement 

 natural cement, as may be specified, shall be u- 

 B brand known by prior use on extensive works 

 quality. Any cement not so known may be 



