A. Pourbakhtiar, “Pilot Study of Method for Constructing Concrete Seals and Fracture Grouts in Deep Boreholes and Cementitious Backfills in Tunnels, Drifts and Shafts in Crystalline Rock,” Master Thesis, Lulea University of Technology, Lulea, 2012.

has been cited by the following article:

• TITLE: A Talc-Based Cement-Poor Concrete for Sealing Boreholes in Rock

  AUTHORS: Roland Pusch, Laurence Warr, Georg Grathoff, Alireza Pourbakhtiar, Sven Knutsson, Mohammed Hatem Mohammed

  KEYWORDS: Clay; Concrete; Ductility; Strength; Superplasticizers; Talc

  JOURNAL NAME: Engineering, Vol.5 No.3, March 19, 2013

  ABSTRACT: Deep investigation boreholes in crystalline rock for site selection of repositories for high-level radioactive waste are proposed to be sealed by installing a series of dense concrete and clay plugs. These should prevent radionuclides from leaking canisters at depth to migrate to the biosphere through the holes. The concrete seals will be installed where the holes intersect water-bearing fracture zones to serve as stable and low-permeable supports for adjacent clay plugs. Low porosity and microstructural stability must be guaranteed for many thousands of years and ordinary Portland cement with organic superplastizer will not fulfill the requirements since the high pH will cause degradation of contacting clay and the organic additive can produce colloids with a capacity to carry radionuclides up to the biosphere. Very cement-poor concrete (