NO. 96 - June 1957 



II-E "Factors Affecting Durability of Concrete in Coastal 

 F Structures" by Bryant Mather 



Both internal and external factors which affect the 

 durability of concrete structures are discussed in 

 detail. Mixing and construction practices are dis- 

 cussed at length. Test data from several agencies, 

 service records of concrete structures at numerous 

 locations, and a substantial list of references are 

 appended . 



NO. 97 - July 1957 



I-A "Turbulent Flow Near an Oscillating Wall" by George 

 F Kalkanis 



Results of theoretical and experimental work to define 

 a law describing the flow near the bottom due to 

 surface waves are presented. Flow conditions are 

 described mathematically for the case of waves of lew 

 amplitude in deep water and a smooth bottom. Coefficients 

 are defined by experiment using an oscillating bed in a 

 laboratory tank. 



NO. 98 - June 1957 



II-A "Hurricane Wave Statistics for The Gulf of Mexico" by 

 Basil W. Wilson 



This report contains the results of a statistical hind- 

 cast study of heights and periods of significant waves 

 generated by hurricanes in the Gulf of Mexico in the 

 period 1900 to 1949. Results are presented in a series 

 of polar plots of frequencies of occurrence of waves of 

 given height and period at 5 deep water (100 fathoms) 

 stations offshore in the Gulf of Mexico, This report 

 complements Technical Memoranda Nos. 84 to 89 which 

 presented statistical sununaries for all or ordinary 

 wind waves hindcast for the same stations. 



NO. 99 - September 1957 



I-A "Model Tests on a Triple-Bulkhead Type of Floating Breakwater" 



E by Culbertson W. Ross 



F 



Test procedures and results are summarized for a laboratory 

 model study to test the effectiveness of a particular design 



110 



