Submicroscopic Deformation in Cement Paste and Mortar at High Load Rates

Abstract

Submicroscopic cracking and strain-rate response of cement paste and mortar under uniaxial compression were measured and correlated with applied strain. Cement paste specimens with water-cement ratios of 0.3, 0.4, 0,5, and 0, 7 and mortar specimens with water-cement ratios of 0.3, 0.4, and 0.5 were subjected to monotonic load at strain rates ranging from 0.3 to 300,000 microstrain per second. Specimens were tested at ages ranging from 27 to 29 days. After loading, slices of material were removed from selected speciment for study at magnifications of 125x and 2500 x in a scanning electron microscope. Image analysis instrumentation was used in later stages of the study. Cracks on transverse and longitudinal surfaces were measured, and three-dimensional crack distributions were obtained from the crack data. The portion of the nonlinear material response caused by the cracks was estimated using a self-consistent material model. Cement pastes; Compression; Concretes; Cracking (fracturing), Electron microscopes; Image analysis; Isotropy; measurement; Microcracking; Microscopic; Microstructures; Mortars (material) strains; Strain rate; Stress; Stress-strain diagram.

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Document Details

Document Type
Technical Report
Publication Date
Aug 15, 1988
Accession Number
ADA205016

Entities

People

  • David Darwin

Organizations

  • University of Kansas

Tags

Communities of Interest

  • Weapons Technologies

DTIC Thesaurus Topics

  • Air Force
  • Compressive Strength
  • Concrete
  • Construction
  • Construction Materials
  • Elastic Properties
  • Electron Microscopes
  • Instrumentation
  • Material Degradation Processes
  • Materials Laboratories
  • Measurement
  • Mechanics
  • Microscopes
  • Modulus Of Elasticity
  • Scanning Electron Microscopes
  • Shear Modulus
  • Stress Strain Relations

Fields of Study

  • Materials science

Readers

  • Materials Science (Mechanical Engineering).
  • Mechanical Engineering/Mechanics of Materials.
  • Surface Coatings Technology.

Technology Areas

  • Microelectronics