ISSN: 0149-6115
Page Count: 10

Laboratory Evaluation of Cemented Backfill Materials for Mines

Unal, E
Associate professor of mining engineering and research assistant,Middle East Technical University, Department of Mining Engineering, Inonu Bulvari, ODTU,

Cakmakci, G
Associate professor of mining engineering and research assistant,Middle East Technical University, Department of Mining Engineering, Inonu Bulvari, ODTU,

(Received 13 May 1999; accepted 19 April 2000)

Abstract

A brief state-of-the-art review is given on backfill materials and laboratory tests. A new system developed for testing backfill material in the laboratory is described. In this system, most of the limitations of previously applied techniques have been eliminated. In performing unconfined-deformability tests (UDT) and confined-deformability tests (CDT), large cylindrical specimens having a diameter of 600 mm are used. The specimens were prepared from riverbed sand and gravel mixed with cement. A total of 135 UDT and 127 CDT specimens were tested in order to investigate the strength and deformability characteristics of 40 different combinations of backfill mixture. Calculation methods are evaluated in terms of stress-strain plots and are illustrated with examples. Typical results are presented. Two sets of deformation data can be obtained during testing: one from between the top and bottom plates, and the other from between the rings peripherally fixed onto the specimen. It is shown in this study that ring-to-ring readings provide more reliable modulus results.

Keywords:
backfill testing, cemented backfill, laboratory characterization of backfill, large-scale laboratory backfill specimen, unconfined deformability test, confined deformability test

Paper ID: GTJ11070J
DOI: 10.1520/GTJ11070J
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