Estimating the Unconfined Compressive Strength (UCS) of Emplaced Cemented Rockfill (CRF) from QA/QC Cylinder Strengths

Details

• Personal Author:
  Armstrong J ; Dehn KK ; Raffaldi MJ ; Sandbak LA ; Seymour, Joseph B. ; Warren SN
• Description:
  Confidence in the design and stability of an undercut cemented rockfill (CRF) span requires a thorough understanding of its emplaced material properties. The unconfined compressive strength (UCS) of cast 6×12-inch QA/QC cylinders is typically used as an index test to track the performance of a backfill plant. However, these strengths need to be adjusted for oversize aggregate removal and sample size effects if used to estimate the emplaced UCS. UCS testing of 6×12, 12×24, and 18×36-inch cast CRF cylinders was used to quantify the relationship between readily available 6×12-inch QA/QC strength data and the emplaced UCS. Test results indicate that the UCS of 18×36-inch cylinders is roughly 40% of the 6×12-inch UCS for similarly compacted samples. Mine QA/QC data indicate that the UCS of CRF is highly dependent on the degree of compaction as measured by bulk density. Based on these results, knowledge of the emplaced CRF density compared to 6×12-inch QA/QC density is also necessary to estimate the emplaced UCS. The scale effect reported in this study is more pronounced, compared to current understanding of backfill properties discussed in the literature, and underscores the need for further site-specific testing. [Description provided by NIOSH]
• Subjects:
  Geology Mining Occupational Health Quality Control Safety
• Keywords:
  Aggregates Cements Compressive Strength Concretes Environmental Technology Fracturing Geotechnical Engineering Limestone Materials Testing Mine Safety Mining-industry Performance Tests Quality Assurance Quality Control Rock Mechanics Structural Analysis Structural Design Structural Failure Underground Mines

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• Series:
  Mining Publications
• Publisher:
  Society for Mining, Metallurgy, and Exploration, Inc.
• Document Type:
  Text
• Genre:
  Proceedings
• Place as Subject:
  Colorado ; Minnesota ; Nevada ; OSHA Region 10 ; OSHA Region 5 ; OSHA Region 8 ; OSHA Region 9 ; Washington
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  SMRD - Spokane Mining Research Division
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  1-9
• NIOSHTIC Number:
  nn:20051335
• Citation:
  2018 SME Annual Meeting, February 25-28, 2018, Minneapolis, Minnesota, preprint 18-031. Englewood, CO: Society for Mining, Metallurgy, and Exploration, Inc., 2018 Feb; :1-9
• Contact Point Address:
  S. N. Warren, NIOSH, Spokane, WA
• CAS Registry Number:
  Limestone (CAS RN 1317-65-3)
• Federal Fiscal Year:
  2018
• NORA Priority Area:
  Mining
• Peer Reviewed:
  False
• Source Full Name:
  2018 SME Annual Meeting, February 25-28, 2018, Minneapolis, Minnesota, preprint 18-031
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:f77023a63e55de0db22df8ea6e14ab2aaa1ee137b81d88dedd3925fa376d8a3449bf5af01f6709ce9a0b874f89a6f3428c02e49a9186c44842af270217ab1bbf
• Download URL:
  https://stacks.cdc.gov/view/cdc/227655/cdc_227655_DS1.pdf
• File Type:
  [PDF - 1.52 MB ]