Applications of the Scanning Electron Microscope to Concrete Failure (Axial, Biaxial, and Dynamic).

Abstract

The major objective was to directly observe the formation and/or propagation of microcracks in concrete (plain and reinforced) both before and after applications of axial, biaxial, and dynamic stress fields. As part of this objective; procedures, techniques, apparatus, and equipment were developed and/or modified for the study of concrete fracture utilizing the Scanning Electron Microscope (SEM). In addition, information regarding microcracks, propagation of these microcracks (concrete failure), aggregate shape, plain and reinforced concrete, the sum effect of various stress fields, and the ultimate strength of concrete was found. Information regarding microcracks, aggregate shape, plain and reinforced concrete, the sum effects of various stress fields, and the ultimate strength of concrete was found for concrete containing blended cements. Concrete may fail from applied service loads or applied stress fields whether they are axial, biaxial, or dynamic. Also, concrete may fail as a result of volume changes such as the hydration of the cement paste leading to the shrinkage microcracks or to various cycles of wetting and drying or temperature variations (freezing and thawing). Thus, a model previously developed was investigated and the equations developed were found to be appropriate.

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Document Details

Document Type
Technical Report
Publication Date
Mar 05, 1984
Accession Number
ADA141788

Entities

People

  • K. Derucher

Organizations

  • Stevens Institute of Technology

Tags

Communities of Interest

  • Weapons Technologies

DTIC Thesaurus Topics

  • Air Force
  • Biaxial Stresses
  • Chemical Reactions
  • Electron Microscopes
  • Engineering
  • Equations
  • Failure Mode And Effect Analysis
  • Materials
  • Materials Science
  • Mechanics
  • Modulus Of Elasticity
  • New Jersey
  • Plastic Explosives
  • Reinforced Concrete
  • Scanning Electron Microscopes
  • Scientific Research
  • Stress Strain Relations

Fields of Study

  • Engineering

Readers

  • Pavement Materials Engineering.
  • Reinforced Composite Materials
  • Structural Dynamics.

Technology Areas

  • Microelectronics