222 



REIBLING AND REYES. 



The results and conclusions derived from this study of commercial 

 and selected material are as follows : 



THE SETTING PROPERTIES OF XON-SEASONED, NON-PLASTERED PORTLAND CEilENT. 



The original plastic and setting properties of these cements were 

 essentially the same. Groimd to different degrees of fineness, kneaded 

 one and one-half or troweled five minutes, they all required a large 

 amount of water to produce a paste of normal consistency and the neat 

 mortar set in an abnormal, erratic manner. Also, in each case the 

 plasticity was abnormally poor, it being extremely difiicult to produce 

 a paste which would give a penetration of 10 millimeters to the con- 

 sistency needle, unless the cement was gauged so wet that water after- 

 wards ran out from the bottom of the mold. On the other hand, if less 

 water than that required to produce a paste of normal consistency was 

 used, the neat mortar obtained was friable, sandy and more or less 

 incapable of proper molding. These characteristic physical properties 

 are shown by the figures in Table XXIV, and by the curves of the set 

 plotted in figure 16. 



Table XXIV. — Characteristic setting and plastic properties of normal consistency 

 pastes made from non-plastered, non-seasoned Portland cements. 



•6 



Temperature of laboratory 

 during gauging and setting. 



Fineness 

 through— 



O 



i 



•o . 



g 



PL, 



^2 



■ss 



£ " 



8a 



•ss 

 ca 



£» 



0) 



a 



a 



Is 



II 

 If 



g.s 



'a 



Time of setting. 



Soundness 

 (5 hours steam test). 





Initial. 



Final. 



J3 



s 



a 



a 



o 

 o 



§ 



1 



a 



S 

 s 

 o 

 W 



1 



S 





 K 



L 



Oi 

 Oi' 

 Oi" 



27°-30° 

 28°-30° 



26°. 5-30° 



28°-30° 



28°-30° 



26. °5-29° 



P.ct. 



89.6 



93.2 



93.6 



74.8 

 74.8 

 93.8 



p.ct. 

 99.0 



99.7 



100.0 



87.8 

 87.8 

 99.7 



27.5 

 30.0 



29.0 



28.0 

 28.0 

 29.0 



10 

 10 



10 



8 

 8 

 10 



40.0 

 40.0 



40.0 



40.0 

 40.0 

 40.0 



2 

 4 



4 



il 

 \l 



ii 

 I 2 



30? 

 10? 



30 



45? 

 50 

 40? 

 20 

 20? 

 



6— 

 8— 



6 



]' 

 }' 



X 



X 



20 



X 

 X 

 X 



Scaly, off plate and a little 



soft, but not disintegrated. 



Few hair-lilie, radial cracks, 



but hard and free from 



warping. 



Off plate, but free from 



cracks or warping, 

 f Soft and slightly disinte- 

 l grated. 



Slightly disintegrated. 

 Do. 



