Table 22. Effect of commonly used chemicals on concrete. 



Rate of 













attack at 













ambient 



Inorganic 



Organic 



Alkaline 



Salt 





temperature 



acids 



acids 



solutions 



solutions 



Miscellaneous 



Rapid 



Hydrochloric 



Acetic 



-_ 



Aluminum 



_- 





Hydrofluoric 



Formic 





chloride 







Nitric 













Sulfuric 







Ammonium 

 nitrate 



Ammonium 

 sulfate 

 Sodium 

 sulfate 



Bromine (gas) 

 Sulfite liquor 



Moderate 



Phosphoric 



Tannic 



Sodium 

 hydroxide- 

 > 20 pet 1 



Magnesium 

 sulfate 

 Calcium 

 sulfate 











Sodium 



Ammonium 



Chlorine (gas) 









hydroxide 



chloride 



Seawater 









10 to 20 



Magnesium 



Softwater 









pet 1 



chloride 











Sodium 







Slow 



Carbonic 



"' 



hypochlorite 



Sodium 

 cyanide 











Sodium 



Calcium 



Ammonia 









hydroxide 



chloride 



(liquid) 



Negligible 





Oxalic 

 Tartaric 



< 10 pet 1 



Sodium 

 hypochlorite 

 Ammonium 

 hydroxide 



Sodium 

 chloride 

 Zinc nitrate 

 Sodium 

 chromate 





^void siliceous aggregates because they are attacked by strong solutions 

 of hydroxide. 



The first record of marine animals entering concrete is found in Hill 

 and Kofoid (1927). This record indicated that Pholadidae were found 

 drilling into concrete jackets used to protect wood piles from attacks by 

 Limnoria and Teredo. Subsequent tests showed that the mortar jackets bore 

 no resemblance to even a poor grade of structural concrete and offered no 

 resistance to the boring mechanisms of Pholads. 



While mollusks have been found in lightweight mortar pontoons, of 

 dubious quality, additional tests prove that Pholads could not enter any 

 material harder than their shells (about 2.5 on the diamond scale). 



146 



