XI, A, 6 



Witt: The Effect of Sulphide on Cement 



279 



Table IV. — Effect of a solution of hydrogen sulphide on setting time of 



cements. 



Brand. 



Initial set. 



Final set. 



Water 

 only. » 



Sodium 

 sulphide. 



S= 1. 06 

 grams per 



liter, a 



Hydrogen 

 sulphide 

 solution. 

 8= 0. 91 

 gram per 

 liter. 



Water 

 only. a 



Sodium 

 sulphide. 



S=1.06 

 grams per 



liter.a 



Hydrogen 

 sulphide 

 solution. 

 S= 0. 91 

 gram per 

 liter. 



A 



Hrs. min. 

 5 15 



3 55 



4 32 

 4 26 

 4 14 



Hrs. min. 

 5 54 

 5 2 

 5 37 

 4 64 

 2 51 



Hrs. min. 

 6 7 

 4 7 

 4 61 

 3 37 

 2 14 



Hrs. min. 

 9 6 



6 40 



7 16 



7 4 

 6 36 



Hrs. min. 

 12 32 

 11 17 

 11 20 

 11 39 

 8 11 



Hrs. min. 

 8 52 



7 35 



8 13 

 6 27 

 5 49 



B- 



C- 



D.... 



E 





All soundness tests were satisfactory. 

 ^ These results were taken from Table III for the sake of comparison. 



It is possible that in some of the higher concentrations of 

 sodium sulphide solutions the sodium may have some influence, 

 but for reasons already stated, a comparison with hydrogen 

 sulphide cannot be made. 



TENSILE STRENGTH TESTS 



From the results given in Table III, the concentrations of 

 the solutions for making the tensile strength specimens were 

 decided on. A solution containing as much as 20 grams of 

 sulphide per liter in some cases renders the cement quick-setting 

 and causes trouble in making the briquettes properly. There- 

 fore, to avoid any abnormalities in the briquette molding, it 

 was decided to use no solution stronger than 10 grams per liter. 

 The number of briquettes to be made with each cement and 

 each solution was very large; consequently the number of 

 solutions was limited to four. A stock solution was accordingly 

 made to contain approximately 10 grams per liter. Portions 

 were withdrawn from the stock bottle and diluted to give %, 

 %o» and Yioo of the original. The exact strength of each 

 solution (by analysis) was as follows: 



Solution 1 contained 9.70 grams sulphur, as sulphide, per liter ; 

 2, 4.80 grams; 3, 0.97 gram; and 4, 0.097 gram. 



Neat briquettes were made for the periods one, seven, twenty- 

 eight, sixty, one hundred twenty, and one hundred eighty days ; 

 and for one, two, three, and five years. Mortar briquettes (one 

 part cement to three parts Ottawa standard sand) were made 



