SPECTRAL ANALYSIS OF RANDOM SHRINKAGE STRESSES IN CONCRETE

Random variation of environmental humidity is characterized by its power spectrum, and random variation of pore humidity and stresses in a half-space is analyzed under the assumption that the problem is linear. The diffusion equation and the superposition integral for stress relaxation are used. The dependence of both the creep properties and the drying diffusivity on age is taken into account. Complex variable expressions for the frequency response functions of humidity and stress are obtained and are evaluated numerically. In contrast to nonaging structures, these functions depend on both the current age of concrete and the age when drying starts. The standard deviations of pore humidity and of stress exhibit oscillations about a drifting mean. For typical diffusivities of concrete, the solution is nonstationary for at least 50 yr, and for environmental fluctuations whose period does not exceed one year, the fluctuations are not felt at depths over 20 cm below the surface.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/07339399
• Corporate Authors:

  American Society of Civil Engineers

  345 East 47th Street
  New York, NY  United States  10017-2398
• Authors:
  • Bazant, Z P
  • Wang, Ting
• Publication Date: 1984-2

Media Info

• Features: References;
• Pagination: p. 173-186
• Serial:
  • Journal of Engineering Mechanics
  • Volume: 110
  • Issue Number: 2
  • Publisher: American Society of Civil Engineers
  • ISSN: 0733-9399
  • EISSN: 1943-7889
  • Serial URL: http://ascelibrary.org/journal/jenmdt

Subject/Index Terms

• TRT Terms: Age; Analysis; Concrete; Depth; Diffusion (Optics); Equations; Frequency response; Humidity; Moisture content; Shrinkage; Spectrum analysis; Stresses; Variance
• Old TRIS Terms: Concrete shrinkage; Fluctuation; Strippers
• Subject Areas: Geotechnology; Highways; Materials; I51: Earthworks and Soil Drainage;

Filing Info

• Accession Number: 00387003
• Record Type: Publication
• Source Agency: Engineering Index
• Files: TRIS
• Created Date: Aug 30 1984 12:00AM