PARTICLE CONTACTS IN DISCRETE MATERIALS

The purpose of this research was to ascertain any possible relationship between the particle contacts in granular materials and their porosity. A container was filled with various particles ranging from glass marble to pieces of angular aggregate. Paint was pumped into the sample from the bottom, allowed to drain and then left to dry. The mixture's porosity was determined from the volume of paint drained from the sample. Particle contacts were indicated by unpainted patches on the particles, and the number of contacts per particle was counted at several elevations within the specimen. The product of the sample's porosity times the number of contacts per particle ranged from 2.70 to 3.30, averaging at 3.00. Samples of painted materials were also subjected to triaxial tests. Two basic types of motion were observed: sliding and rotation. Sliding predominated at the upper and lower surfaces of the specimen (against the end plates) where rotation is at a minimum. Rotation occurs much more often at the specimen's curved surface than within its interior. The deformation pattern along the curved surface is not symmetical but exhibits a spiral like effect. This spiral begins at the upper and lower end parts of the curved surface and moves toward the center around it, possibly as a result of the relative distortion between the riged plates of the triaxial test.

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  • Accession Number: 00314622
  • Record Type: Publication
  • Report/Paper Numbers: ASCE 15433
  • Files: TRIS
  • Created Date: Oct 8 1980 12:00AM