RESEARCH AND DEVELOPMENT RECOMMENDATIONS 

 Materials 



Saturated Concrete . A study on saturated concrete is required 



to determine the effect of partial and full saturation on 



the engineering properties of concrete. It is important that the material 



behavior used in the analysis be that of concrete representative of the 

 concrete condition in the OTEC structure. The field condition for the 

 concrete in the OTEC structure will be partially saturated to fully saturated, 

 reinforced, and prestressed concrete subjected to sustained and intermit- 

 tent service loads in a hydrostatic environment. In this environment, 

 seawater enters concrete at ambient pressure filling a portion of the void 

 volume. Some portion of the void volume will remain at atmospheric pres- 

 sure, and the concrete experiences a triaxial loading effect. The engi- 

 neering properties of concrete during this partial saturation stage is 

 dependent on the seawater absorption rate. Therefore, the rate of sea- 

 water absorption must be monitored along with the engineering properties 

 of concrete when specimens are tested in a hydrostatic environment for 

 compressive strength, tensile strength, modulus of elasticity, Poisson's 

 ratio, and creep. These same engineering properties need to be obtained 

 for fully saturated concrete. Comparison of these results to continuously 

 fog-cured specimens is essential. This type of study will yield results 

 for the design engineer so that an accurate analysis of the structure can 

 be conducted using known concrete properties. 



Corrosion of Reinforcement . Basic research needs to be conducted to 

 understand the fundamental mechanism of corrosion and sources of electro- 



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