Determination of Optimum Tropic Storage and Exposure Sites. Report 2. Empirical Data
1974
Sprouse, J. F. | Neptune, M. D. | Bryan, J. C.
See also Report dated Apr 1973, ADA005016, and Phase 2 dated May 1974, ADA005018.
显示更多 [+] 显示较少 [-]A total of 238,850 microscope, photographic, tenstile strength, weight loss, reflectivity and transmissivity data points were collected during the course of this study. The investigation used nine experimental field test sites, seven established sites having past histories of use for tropic testing, and one air-conditioned control site for measuring site severity rates and patterns. The test sites existed throughout the Canal Zone on the Pacific coast, Atlantic coast and approximately at mid-Isthmus. Six basic materials representing three general material classes--textiles, metals and rubber--were used as indicators of site severity. These basic materials were cotton, polyvinyl chloride, nylon, latex rubber, butyl rubber and carbon steel. Materials were exposed at the tropic test sites for periods of 1 to 48 weeks during four seasonal exposure phases with tensile strength, corrosion weight loss, and microbial coverage used as experimental measurements of site severity. Results showed that individual tropic exposure sites do not provide uniform severity to all materials. The study provides tables of sites generally homogeneous in deterioration for steel, cotton, nylon, polyvinyl chloride and latex rubber. It also gives severity comparisons between experimental and established sites, Atlantic versus Pacific sites, and sites with different degrees of natural and man-made protection from the environment, such as lean-to shelters, the natural jungle canopy, open grasslands, coastal sites, and mangrove forest (swamp).
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