394 



REIBLING AND REYES. 



Table VIII. — Soundness 





■4-S 



P 





Fineness. 









6 

 Z 



a> 

 o. 



a 



CO 



a^ 



*<.2 

 °2 



eg 



OH 

 C — 

 oj 

 (-, 



Nature of 

 sample. 









Classifi- 

 cation 



bv 

 White. 



Microscopic examination (duplicate 

 samples, Bureau of Science). 



Micro- 

 scopic. 



21 



O CO 



fi a 



it 



O vj 

 ^ CD 



^ a 



10 







Same as above 

 exposed to 

 aeration in pan 

 36 days with 

 daily remixing. 



Coarse.. 



75.3 



90.1 



Sound. 



5 minutes, 15 minutes, 1 hour. No 

 crystals. 



11 







Rotary clinker 

 aerated in lab- 

 oratory 3 

 months and 

 then ground in 

 ball mill. 



Fine 



81.6 



99.0 



Bad .. 



A fair amount of long rosettes of 

 needles somewhat feathery. No 

 increase after 5 minutes. One 

 feathery petal in 1 hour. 



12 







Same as No. 10 

 except that 1.5 

 per cent plaster 

 was mi xed 

 with the u n - 

 aerated cement. 



Coarse __ 



75.8 



90.1 



Sound- 



No plumes and only a few rosettes 

 of needles. 



It will be seen that the agreement between the microscopic evidence 

 and results of the physical test is closer than was to be nxpected. 



