Table A-1. Summary of Concrete Compressive Strengths for the Seacon Structure 



Specimens 



Age of 

 Concrete 



(days) 



Compressive 



Strength 



(psi) 



Type 



Size 

 (in.) 



Number 



Curing 

 Conditions" 



cast 



cast 

 cast 



cast 

 cast 



cast 

 cast 

 cast 



core 



6x12 



6x12 

 6x12 



6x12 

 6x12 



6x12 

 6x12 

 6x12 



3.25x6 



6 



2 

 2 



3 

 3 



6 

 3 

 3 



7 



field 



fog 

 field 



fog 

 field 



fog 

 fog and ocean 

 field and ocean'^ 



part of structure 



28 



96 

 96 



294 



294 



608 

 608 

 608 



2,128 



7,800 



7,070 

 8,550 



9,190 

 9,710 



8,710 

 8,620 

 8,370 



10,470 



"Curing of all cylinders for the first 28 days was 2 days steam, 7 days water tank, 

 and 19 days field. 



After first 28 days, curing was 270 days fog room and 302 days on seafloor at 

 600 feet. 



'^ After first 28 days, curing was 270 days field and 302 days on seafloor at 600 

 feet. 



Structure was field-cured on land for 298 days, on the seafloor for 302 days, and 

 then field-cured on land for 1,528 days. 



As shown in Figure A-1, the concrete cylinder structure was 

 mounted in a steel framework and fitted with a baUast tank. The in-air 

 weight of the cylinder was 85,000 pounds (38.5 Mg), and the concrete- 

 steel structure weighed 102,000 pounds (46.3 Mg) . The positive buoy- 

 ancy of the concrete hull was 12,000 pounds (5.4 Mg), and when bal- 

 lasted the concrete-steel structure weighed 6,800 pounds (3.1 Mg) 

 negative in water. 



33 



