144 REIBLING AND SALINGER. 



Table V. — Test with dried and mulried cement taken from paper hags. 

 [Mortar, 1 to 3. Temperature of room during molding and setting. 29° to 30° C] 



Sample 



No. 

 (same 

 brand). 



Condition. 



Condition of mortar 

 when molded. 



Age. 



Pounds 



per 

 square 

 inch. 



Water 

 used. 









Days. 





rer cent. 



r3-9 



Dried and exposed lo air 10 days 



Set in 10 minutes 



7 1 79 



12. 5 



F3-9 



Dried and exposed to air 10 days 



Set in 12 minutes 



7 



98 



14 



F3-9 



Dried and talien fresli from sample 

 package. 



Not set in 20 minutes. 



7 



18G 



14 



F4-4 



Dried and exposed to air 10 days 



Set in 12 minutes 



7 



70 



12.5 



F4-4 



Undried, freslifroni sample paeliage. 



Not set in 20 minutes; 



7 



182 



12.5 



F4-4 



Fresh from sample heated at 100° 

 C exposed 1 day. 



Not set in 20 minutes. 



6 



157 



12.5 



F4-4 



Fresh from package undried 



Not set in 20 minutes. 



7 



(») 



12.5 



F4-S 



Dried and exposed to air 10 days 



Set in 10 minutes 



7 



92 



12.5 



F4-S 

 F4-9 

 F4-10 



Dried and exposed to air 10 days 



-Undried, fresh from sample package_ 



Set in 12 minutes 



Not set in 20 minutes. 



7 



101 



166 



I 178 



14 



7 



12.5 



"8 briquettes— liB lowest 183 highest. 



Percentage of water evaporated from F4-4 in drying was 0.66. 



In all cases not specified the highest of four good breaks is recorded. 



These results demonstrate that heating did not cause quick setting, 

 and low tensile strength, but exposure to air in open jars for ten daj's did. 

 Table Va illustrates the same action : 



Table Va. 

 [28 days: mortar, 1 to 3.] 



Sample No. 



Water. 



stored. 



After 10 

 days. 



After 30 

 days. 



After 50 

 .days. 



1 

 XI 



Per ct. 

 12J 

 12i 

 12i 

 12i 



Covered can 



Uncovered can — 



Covered can 



Uncovered can... 



315 

 247 

 300 

 245 



302 



205 



•298 



198 



295 

 1.38 

 202 

 147 



XI 



X2. 



X2 





"Cover removed from can on thirtieth day. 



