1.6 



1.4 



1.2 



K 1.0 -' 



0.6 



I I 



Curing Environment 

 O Fog room, 73°F (22.7 °C) 

 X In-ocean, 40°F (4°C) 



Depth (ft) 



concrete placed in ocean 



X 2,790 



o 



- 2,635 

 ^ 3,140 



I / 1,125 ft ^ ^ 



\^ -^ \ ^X' 4,330 ft 



alternate 

 estimated paths 



X 



nominal f ' = 8,000 psi 

 28-day fog cure 



Each datum point avg of three or four specimens. 

 Control cylinder size, 6 x 12 in. 



3 



Total Age (yr) 



Figure 10. Relative compressive strength of fog-cured and ocean-cured concrete. 



It can also be speculated that the 

 cold temperature environment of the 

 ocean had a small effect on retarding 

 full development of strength gain. The 

 ocean temperature was W¥ ('^O, 

 v/hereas the fog room environment was 

 73F (22. 8C). Discussion of the long-term 

 effect of a continuous W¥ (4C) curing 

 environment was not found in the litera- 

 ture. Lorman (Ref 7) gave limited test 

 results on concrete that set and cured 

 under seawater at klV (8.3C) compared 



to that in a 73F (22. 8C) fog environment. 

 After 28 days, the concrete in the cold 

 environment showed a compressive 

 strength that was approximately 10% 

 less than the control concrete. 



The important findings from the 

 data are: (1) the ocean-cured concrete 

 required 1 to 2 years in the ocean before 

 regaining a strength equal to its 28-day 

 fog strength; and (2) within the time 

 period of up to 5.3 years, the strength of 

 the concrete in the ocean was 15 to 20% 

 less than that of continuously fog-cured 

 concrete. 



l'^ 



