Tensile Crack Exposure Tests. Report 3. Laboratory Evaluation of Series 'A' Beams with Results from 1951 to 1975.
Abstract
A study was begun in 1950 to determine the effects of severe natural weathering to stressed, reinforced concrete beams of various compositions and degrees of stress. The objectives of the study were to obtain information on the long-term weathering of air-entrained and nonair-entrained concrete beams containing steels of different compositions, types of deformation, and having different levels of stress in the steel that caused varying degrees of cracking of the concrete. The beams were fabricated, cured, and loaded at the U.S. Army Engineer Waterways Experiment Station (WES) in 1951, then shipped to Eastport, Maine, and placed on the beach at the natural weathering exposure station on the south side of Treat Island, Cobscock Bay, Eastport, and Lubec. The beams were subjected to twice daily tidal cycles exposing them to wetting under considerable head, and drying to surface dry conditions. The beams were inspected annually during the exposure period and evaluated by a team of inspectors rating the degree of deterioration. Each year, maximum crack widths were measured beginning in 1956 and continuing until 1975 when the exposure period was concluded after 25 years of weathering. The results of the exposure study and the laboratory investigation indicated, among other findings, that stressing the steel to varying levels of stress over the exposure period did not reduce the ultimate moment carrying capacity of the beams; the maximum areas of corrosion occurred at spalled areas; corrosion to the steel could not be located at any flexural crack smaller than 0.015 in. (0.38 mm); and no area of maximum reduction of cross-sectional are due to corrosion occurred at the flexural cracks.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1980
- Accession Number
- ADA081302
Entities
People
- Edward F. O'neil