Accession Number : AD0687373

Title :   TENSILE CRACK EXPOSURE TESTS: REPORT 2, RESULTS OF TESTS OF REINFORCED CONCRETE BEAMS, 1955-1963.

Descriptive Note : Technical memo.,

Corporate Author : ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MISS

Personal Author(s) : Roshore,E. C.

Report Date : NOV 1964

Pagination or Media Count : 37

Abstract : Two series of reinforced concrete beams were made and exposed to severe natural weathering at Treat Island, Maine. The first series (Series A), installed in 1951, consisted of 82 reinforced concrete beams; test variables to be studied were type of concrete (air-entrained versus nonair-entrained), thickness of concrete cover over reinforcing steel (3/4 in. versus 2 in.), type of reinforcing steel (rail steel versus billet steel), type of deformations of the reinforcing steel (ASTM Standard A 305-50T deformations versus old-style deformations), degree of tensile stress in reinforcing steel (0, 20,000, 30,000, 40,000, and 50,000 psi), and position of steel in the concrete beam at the time of casting (top versus bottom). After 12 winters, results indicate that (a) air-entrained concrete beams were significantly more resistant to weathering than nonair-entrained beams, and (b) beams with reinforcing steel having deformations as per ASTM Standard A 305 were more resistant to weathering than those beams having old-style deformations. Other test data are as yet inconclusive. The second series of beams (Series B), installed in 1954, consisted of 76 reinforced concrete beams. The test variables were identical with those of Series A. After 9 winters of exposure, no definite conclusions can be drawn concerning the test variables. Since none of the Series B beams have failed, exposure will be continued. (Author)

Descriptors :   (*BEAMS(STRUCTURAL), ENVIRONMENTAL TESTS), (*REINFORCED CONCRETE, TENSILE PROPERTIES), EXPOSURE(PHYSIOLOGY), WEATHER, CRACKS, STEEL, DEFORMATION, STANDARDS, AGING(MATERIALS), DEGRADATION, FAILURE(MECHANICS), TEST METHODS, SPECIFICATIONS, MAINE

Subject Categories : Construction Equipment, Materials & Supplies
      Structural Engineering and Building Technology

Distribution Statement : APPROVED FOR PUBLIC RELEASE