One-dimensional consolidation parameters of cemented paste backfills


Yilmaz E. , BELEM T., BENZAAZOUA M.

GOSPODARKA SUROWCAMI MINERALNYMI-MINERAL RESOURCES MANAGEMENT, cilt.28, ss.29-45, 2012 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 28 Konu: 4
  • Basım Tarihi: 2012
  • Doi Numarası: 10.2478/v10269-012-0030-2
  • Dergi Adı: GOSPODARKA SUROWCAMI MINERALNYMI-MINERAL RESOURCES MANAGEMENT
  • Sayfa Sayıları: ss.29-45

Özet

Each year, mine and mill operations generate enormous amounts of two waste types fine-grained tailings and coarse-grained waste rocks. Fine-grained tailings are either discharged in slurry form to surface tailings dams or delivered in cementitious form to underground mine stopes as backfilling, while coarse-grained rocks arc typically stored by depositing as a dry material in large dumps. The engineering design of surface tailings dams or underground mine stopes is often controlled by the high compressibility and low shear strength characteristics of fine-grained tailings. Cemented paste backfill CPB indicating saturated, fine-grained backfills can undergo major consolidation settlement during early curing stages. Thus, a better understanding of the rate and magnitude of both differential and total settlement of CPB cured under stress is essential for a proper backfill geotechnical design. The consolidation parameters of CPB can be determined from an improved lab setup called CUAPS (curing under applied pressure system). This setup is capable of simulating the CPB placement and curing conditions, and measuring the consolidation parameters of CPB cured under effective stresses ranging between 0.5 and 400 kPa. In this study, a series of one-dimensional consolidation tests were conducted on CPB samples allowing for examination of the effects of binder type and rate as well as curing time on the compression properties (e.g., coefficient of consolidation c(v), compression index C-c, and recompression index C-r) and the final geotechnical index properties (e.g., void ratio e(f), water content w(f), and degree of saturation S-f). Results showed that as the binder content increases, the initial resistance to consolidation increases. The e value decreases over the course of time due to evolution of the CPB microstructure generated by the hydration process.