IX, A, 2 Reihling and Reyes: Portland Cement Materials 135 



special significance, because the materials represented by samples 

 35, 37, 39 (combined), and 47 are most desirable from the point 

 of view of field relations, 



A second series of tests was made which included mixtures 

 similar to 1, 2, and 3, but somewhat modified in composition, 

 and mixture 5 for which limestone 46 was combined with clay 47. 

 The essential characteristics of these four mixtures are given 

 in Table V. 



Table V. — Characteristics of second four cement mixtures. 



Mix- 

 ture 

 No. 



Material. 



Parts of 

 weight. 



Fineness 

 through 



the 



lOO-mesh 



sieve. 



5 

 la 

 2a 

 3a 



[Limestone 46 



lClay47 



{Limestone 50.-- 

 Clay 48-- 



(Limestones 35, 37, and 39 



lCIay47 



(Limestone 35, 37, and 39- 

 lC!ay51 



100 



25 

 100 



28.4 

 100 



11 

 100 



14 



Per cent. 

 \ 93 



94 



91.2 



95 



ULTIMATE CHEMICAL COMPOSITION OF THE VITRIFIED MIXTURES 

 (BY CALCULATION). 



Constituent. 



Mixture No. 



5. 



la. 



2a. 



8a. 



Silica (Si02) 



Alumina (AI2O3) 



Ferric oxide (Fe203) 



Calcium oxide (CaO) 



Magnesium oxide (MgO) 

 Hydraulic modulus 



25.40 



7.10 



64.50 

 2.06 

 2.04 



23.36 

 5.29 

 5.52 



62.23 

 1.42 

 1.86 



25.30 

 4.06 

 3.04 



63.00 

 1.27 

 1.90 



22.30 

 3.87 

 4.44 



64.40 

 1.52 

 2.16 



REFRACTORY PROPERTIES. 



Mix- 

 ture 

 No. 



Observations. 



la 

 2a 

 8a 



Highest temperature obtainable required to produce well-burned clinker; no fusing and 



no dusting. 

 Easily sintered; slight tendency to dust if cooled slowly. 

 Similar to No. 1 and a little less refractory than No. 2. 

 Refractory properties better than No. 3, and no tendency to melt or fuse on cooling. 



