210 



ANNALS NEW YORK ACADEMY OF SCIENCES 



Effect of gaging ivith various solutions upon the strength of mortars 

 afterward stored in water.- — The above tests do not show, of course, a 

 normal condition, since no water came into contact with the cement 

 after it had set. Working with more porous material, a 1 : 3 mortar, so 

 that in storage a heightened subsequent water action might take place, 

 the following results were obtained : 



Table 19 



Effect of various Salts dissolved in the Mixing Water, upon the Strength of 



1:3 Mortar 



(Sand, screened Cow Bay. Specimens stored in damp closet for 24 hours, then 

 continuously in water for the rest of period) 



Mixes 



Compressive strength, 

 pounds per square inch 



Number of 

 specimens 



7 days 



28 days 



3 months 



Water 



815 



1005 



945 



1010 



885 



910 



865 



935 



1090 



930 



840 



1105 



1000 



1475 

 1185 

 1310 

 1520 

 1240 

 1625 

 1410 

 1595 

 1580 

 1605 

 1490 

 1385 

 1035 



2600 

 1805 

 2170 

 2420 

 2100 

 2145 

 2115 

 2710 

 2500 

 2670 

 2710 

 2000 

 1685 



1,3,3 

 3,2,1 

 3,3,3 

 3,3,3 

 1,3,3 

 2,3,3 

 2,3,3 

 3,3,2 

 3,1,2 

 3,3,3 

 2,1,1 

 3,3,3 

 2,3,3 



5,6,6 

 6,6,6 

 4,6,5 

 6,6,6 

 4,6,6 

 3,6,6 

 4,6,6 

 2,5,6 

 3,6,6 

 5,6,6 

 5,6,6 

 6,6,6 

 5,6,5 



1 % solution of A1 2 (S0 4 ) 3 



2% do. 



1 % solution of NajS0 4 



2% do. 



1 % solution of MgS0 4 



2% do. 



1 % solution of ZnS0 4 



2 % do. 



1 % solution of FeS0 4 



2% do. 



1 % solution of NaCl 



2% do. 







Tensile strength, pounds per 

 square inch 



1 days 



28 days 



3 months 



Water 



179 

 208 

 193 

 216 

 205 

 194 

 185 

 126 

 205 

 201 

 184 

 211 

 224 



272 

 272 



262 

 290 

 300 

 260 

 246 

 263 

 272 

 266 

 258 

 261 

 279 



326 

 321 

 340 

 354 

 343 

 317 

 283 

 315 

 319 

 314 

 311 

 310 

 310 



1 % solution of Al 2 (S0 4 ) 3 



: 2% do. 



1 % solution of Na 2 S0 4 



2% do. 



1 % solution of MgS0 4 



2% do. 



1% solution of ZnS0 4 



2% do. 



1 % solution of FeS0 4 



2% do. 



1 % solution of NaCl 



2% do. 





