content was leached in approximately 20 days; this Ca leach level 



was reached in about 10 days. 



Erosion Rate of Concrete 



The objective is to state quantitatively, if possible, how long a 



concrete parcel will remain integral when immersed in a sea water 



environment. 



Reference: Kleinlogel, "Influences on Concrete", F. Ungar 

 Co. (1950). " Sea Water. The free lime in concrete has 

 a tendency to react chemically as long as it is not attached 

 to another substance. It combines with the CO_ to form 

 CaCOo, which forms a protective crust on the surface. 

 When sea water has access through pores or cracks to 

 the inside of the concrete, it dissolves the gyps vim and 

 the aluminates as well as the lime. These salts combine 

 with a large quantity of the water of crystallization to 

 form a double salt (Ca-Al-S04) which has a high pressure 

 of crystallization, expands, cracks, destroys the struc- 

 ture of the concrete and transforms it into a soft mass. 

 "In time the lime in the concrete is absorbed by the 

 MgCl probably by forming CaC^ which is soluble in water. 

 The lime is then replaced by magnesia. Consequently, the 

 concrete becomes porous and the sea water can penetrate 

 it. " 



