Appendix A 

 THICK-WALLED CYLINDER TESTS 



SPECIMEN DESCRIPTION 



The SEACON I structure (Figures A-1 and A-2) was assembled 

 from three precast, reinforced concrete sections. The straight cylinder 

 section, 10.1-foot (3.08-m) OD by 10-foot (3.05-m) length by 9.5-inch 

 (241-mm) wall thickness, was fabricated by United Concrete Pipe Cor- 

 poration. The concrete hemisphere end-closures, 10.1-foot (3.08-m) OD 

 by 9.5-inch (241-mm) wall thickness, were fabricated in-house. Toler- 

 ances on the sections conformed to concrete pipe standards : ID not to 

 exceed ±0.75 in. (19 mm) or wall thickness not to exceed -0.5 in. (13 

 mm) . 



Steel reinforcement of 0.70% by area was used in both the hoop 

 and axial direction. Reinforcing bars of 0.50 inch (15 mm) diameter 

 were employed throughout the structure. A double circular reinforce- 

 ment cage was fabricated for each precast section; the concrete cover 

 on the outside and inside reinforcing cage was 1 inch (25 mm). For 

 the cylinder section, hoop rebars had a center- to-center spacing of 6 

 inches, and axial rebars had a spacing of 27.25 inches (692 mm) and 

 31.25 inches (794 mm) for the inside and outside cages, respectively. 



The hemispherical end-closures were bonded to the cylinder section 

 with an epoxy adhesive; no other attachment besides the epoxy bond 

 was employed. The gap between the mating surfaces of the hemisphere 

 and the cylinder was less than 0.13 in. (3 mm) for 75% of the contact 

 area. Prior to epoxy bonding, the concrete surfaces were sandblasted 

 and washed with acetone . 



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