CEMENT TILE FOR ALKALI LAND 



175 



Weakening results from the formation of compounds that 

 expand and break up the concrete. Later the soluble 

 compounds leach out leaving the material not nearly so 



FIG. 24. POORLY MADE CEMENT THAT is BEING 

 CRUMBLED BY ALKALI. 



strong. Neat cement that excluded absorption was not 

 injured by alkali solutions. Meade (9) found that even 

 very dilute solutions of the salts of magnesium and the 

 sulphates in general have a destructive action on concrete. 

 Cements low in alumina were less affected than others. 



