276 



The Philippine Journal of Science 

 Table II. — Physical tests of cements' 



1916 



Brand. 



Fineness. 



Specific 

 grav- 

 ity. 



Sound- 

 ness 

 (five 



hours, 

 in 



steam.) 



Initial 

 set. 



Final set. 



1 

 Tensile strength (neat). 

 Kilos per square centi- 

 meter, b 



Pass- 

 ing 200- 

 mesh 

 sieve. 



Pass- 

 ing 100- 

 mesh 

 sieve. 



Iday. 



7 

 days. 



28 

 days. 



60 

 days. 



A 



Per 

 cent. 



87.6 



81.6 



89.6 



85.6 



88.2 



Per 



cent. 



99.0 

 99.0 

 99.0 

 98.6 

 99.0 



3.12 

 3.10 

 3.16 

 3.10 

 3.10 



O.K. 

 O.K. 

 O.K. 

 O.K. 

 O.K. 



Hrs. min. 



5 15 



3 55 



4 32 

 4 26 

 4 14 



Hrs. min. 



9 6 



6 40 



7 16 

 7 4 

 6 36 



24.8 

 23.6 

 23.2 

 24.5 

 27.3 



41.8 

 43.5 

 41.2 

 44.6 

 44.2 



48.1 

 45.7 

 47.8 

 50.7 

 51.3 



47.3 

 45.7 

 45.3 

 47.5 

 50.6 



B..-. 



C 



D 



E 





Tensile strength (mor- 

 tar). Kilos per square 

 centimeter. 



Tensile strength (neat) . 

 Pounds per square inch. 



Tensile strength (mor- 

 tar). Pounds per 

 square inch. 



Iday. 



7 

 days. 



28 

 days. 



60 

 days. 



Iday. 



7 

 days. 



28 

 days. 



60 

 days. 



Iday. 



7 

 days. 



28 

 days. 



60 

 days. 



7.0 

 7.0 

 9.3 

 8.7 

 10.8 



16.8 

 17.5 

 19.8 

 20.8 

 23.2 



23.4 

 21.7 

 26.7 

 28.8 

 28.5 



25.3 

 22.8 

 30.1 

 30.9 

 29.1 



353 

 337 

 330 

 348 

 388 



595 

 617 

 586 

 633 

 628 



685 

 651 

 679 

 722 

 731 



673 

 649 

 644 

 677 

 720 



100 

 100 

 133 

 124 

 154 



238 

 248 

 282 

 294 

 331 



333 

 308 

 380 

 409 

 407 



360 

 325 

 428 

 441 

 414 



" All physical tests were made in accordance v^ith the specifications given in circular No. 

 33 of the United States Bureau of Standards. 



•> Each result represents the average of six briquettes. 



PRELIMINARY WORK 



An aqueous solution of hy(irogen sulphide first suggested 

 itself as the best source of the sulphide radical for the in- 

 vestigation, because it contains no metal which could cause com- 

 plications. However, the idea was soon abandoned, for it was 

 evident that sufficiently high concentrations of sulphide could 

 not be obtained in such a solution, especially at the high average 

 room temperature in Manila (30° C). Therefore a soluble 

 metallic sulphide (sodium sulphide) was chosen as being better 

 suited for the work. 



A sufficient quantity of sodium sulphide was obtained and 

 analyzed. It was found to contain: 



Per cent. 

 18.83 



Sodium (Na) 



Sulphur as sulphate (SOi) 



Sulphur as sulphide (S) 



0.34 

 11.93 



