IX, A, 2 Reihllng and Reyes: Portland Cement Materials 131 

 Table I. — Ultimate chemical composition of the raw materials. 



Constituent. 









Sample No. 



- 







35. 



37. 



39. 



46. 



47. 



48. 



49. 



50. 



51. 



Loss by ignition 



Total silica (SiQa)— 



35.90 



14.87 

 2.18 

 2.20 



43.12 

 0.87 



trace 

 2.82 

 0.84 



36.70 

 8.94 

 0.43 

 3.09 



47.40 

 0.82 



trace 

 3.51 

 0.66 



38.92 

 8.25 

 2.37 

 0.61 



46.52 

 0.82 



trace 



none 

 0.62 



41.90 

 3.80 



\ 2. 18 



51.59 



1.44 



none 



trace 



0.46 



8.50 



70.28 



11.89 



2.36 



2.55 



0.91 



trace 



9.34 



3.73 



8.07 



60.29 



15.04 



12.05 



1.37 



2.29 



trace 



8.24 



1.18 



8.44 

 58.59 

 18.53 

 7.58 

 2.69 

 2.25 

 0.11 

 5.12 

 2.10 



40.55 

 3.20 

 0.35 

 1.39 



53.16 

 0.59 

 0.10 

 1.76 

 0.36 



19.45 

 41.97 

 8.66 

 9.54 

 15.12 

 2.16 

 0.32 

 2.12 

 2.31 



Ferric oxide (Fe203) 



Calcium oxide (CaO) 



Sulphur oxide (SO3) - 



Free silica 



Total alkalies (Na20, K2O) 



It was thought advisable to combine samples 35, 37, and 39 

 into one mixture composed of equal parts of each. Mr. Pratt 

 states that such a mixture represents the probable average output 

 of the most feasible quarry site, although if desirable it would 

 be almost as convenient to confine operations to the beds 

 represented by 37 and 39. 



The first mixtures prepared for burning were combined so 

 that the hydraulic modulus 



(per cent CaO + per cent MgO\ 

 per cent Si02+per cent R2O3 / 



of each of the resulting cements would approximate 2. The 

 calcareous material represented by the mixture of 35, 37, and 

 39 was given the most consideration, because these limestones 

 are said to be the most conveniently located and most easily 

 quarried of the available calcareous supplies. The essential 

 characteristics of the four mixtures prepared for the first burning 

 tests are given in Table II. 



Table \l.— Characteristics of the first four cement mixtures. 



Mix- 

 ture. 

 No. 



Material. 



Parts by 

 weight. 



Fineness 

 through 



the 



100-mesh 



sieve. 



(LimeBtone 50 



lClay48 _... 



J Limestones 35, 37, and 39. 

 IClay 47 



(Limestones 35, 37, and 39, 



Iciay 51 



[Limestones 35, 37, and 39 

 Iciay 49 



100 

 27 



100 

 9 



100 

 18 



100 

 10 



Per cent. 

 \ 92 



95 



94 



93 



