Table 4. Short-Term Loading Results of Concrete Spheres 



Description 



Sphere 

 Designation 



Concrete 

 Condition^ 



Preload 



Pressure 



(psi) 



Uniaxial 



Compressive 



Strength, 



fc (psi) 



Implosion 

 Pressure, 

 Pirn (psi) 



Ratio, 

 Pim 

 fc 



Elastic 

 Modulus 



of 



Sphere 



Wall, 



E 



(psi X 10^) 



Spheres 

 preloaded 

 in the 

 ocean for 



5.3 yr 



11 



12 

 13 



dry 



saturated 



dry 



1,400 

 1,245 

 1,175 



9,200*^ 

 9,960*^ 

 9,760*^ 



2,970 

 2,750 

 3,115 



0.323 

 0.276 

 0.319 



5.05 

 5.20 

 5.05 



Non-preloaded 

 spheres 

 (after 

 Reference 5) 



CDS-1 

 CDS-2 

 CWS-3 

 CWS-4 



dry 



dry 

 saturated 

 saturated 





 

 

 



9,250 

 9,120 

 7,960 

 7,660 



2,860 

 2,755 

 2,500 

 2,205 



0.309 

 0.302 

 0.314 

 0.288 



4.64 

 4.14 



4.29 



Dry concrete corresponds to coated spheres, and saturated concrete corresponds to uncoated spheres. 



6 X 12-inch (152 x 305-mm) cylinders cored from on-land field-cured concrete blocks prepared from 

 concrete used in spheres. 



6 X 12-inch (152 x 305-mm) cylinders cored from the ocean-cured concrete block attached to 

 Sphere No. 12. 



Table 5. Summary of Short-Term Loading Results 



Spheres 



Implosion Pressure to Compressive Strength Ratio, P. /f , 

 for Spheres 



Coated 

 (dry concrete) 



Uncoated 

 (saturated concrete) 



Preloaded^' 



Non-Preloaded 

 (after Ref 5) 



0.321 

 0.306 



0.276 

 0.301 



Spheres tested in a pressure vessel. 

 In the ocean for 5.3 yr. 



19 



