PHYSICAL PROPERTIES OF PORTLAND CEMENT. 



601 



7 14 21 



70 77 84 



35 42 49 56 

 AGE IN DAYS 

 TENSION 



FIG. 157.* Effect of salt on tensile strength of Portland-cement mortar 



(Tetmajer.) 



4500 



2000 



1500 



FIG. 158.* Effect of salt on compressive strength of Portland-cement mortar. 



(Tetmajer.) 



* From Johnson's Materials of Construction ", p. 620. 

 tlbid. 



