Compressive Stress-Induced Microcracks and Effective Elastic Properties of Limestone and Concrete. Phase 1

Abstract

Stress-induced microstructure alterations were observed in Indiana limestone and one type of using low wetting concrete, point metal alloy injection technique. Average microcrack length and aperture decreased with an increase in applied confining stress. Microcrack density increased with an increase in confining stress. Most microcracks were oriented at a small angle to the maximum compression direction. Theoretical solutions for effective moduli and Poisson's ratios of an axisymmetrically microstructured material were obtained using energy conservation principles. Results showed that all effective moduli are less than for the original undamaged and decreased with an increase in microcrack density. Ultrasonic velocities measured concurrently during static compression tests conformed the observations. 'Dynamic' stress-strain curves constructed from the measured ultrasonic velocities showed relatively similar behavior as the static stress-strain curves. Both static and dynamic moduli decreased with an increase in axial devatoric stress.

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Document Details

Document Type
Technical Report
Publication Date
Apr 19, 1991
Accession Number
ADA237708

Entities

People

  • J. W. Martin
  • John D. Mclennan
  • Ziqiong Zheng

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Air Force
  • Concrete
  • Elastic Properties
  • Elastic Waves
  • Electron Microscopes
  • Electron Microscopy
  • Energy Conservation
  • Failure Mode And Effect Analysis
  • Materials
  • Measurement
  • Mechanical Properties
  • Mechanics
  • Modulus Of Elasticity
  • Stress Strain Relations
  • Stresses
  • Three Dimensional
  • Wave Propagation

Readers

  • Geotechnical Engineering.
  • Structural Dynamics.
  • Structural Health Monitoring of Composite Structures.