Feasibility of emplacement by air cannon of optimised cement-based materials
Air-placement techniques are likely to be used as the means for emplacement of different backfilling materials in underground waste repositories. A literature survey of the air-placement techniques and equipment suggests the choice of the dry process, taking into account the emplacement constraints (distance: 300 m, flow: 10 m3/h) and the large variety of materials to be placed. Tests performed in the case of cement-based materials (with and without addition of silica fumes), for different types of cement and as a function of the incidence of the jet, show that it is possible to put in place mortars of good quality. However, heterogeneity in the material composition is found when the jet is stopped. This problem may be partially solved by better automation of the process. Complementary tests, carried out with the preselected clay of Fourges Cahaignes, clearly demonstrate the ability of the air-placement technique to put in place pure clay: a dry density of 1.50 kg/m3 is reached in the case of coarse material and for a final water content of 30% (in weight). Feasibility tests performed on clay-sand mixtures are not conclusive due to an inappropriate granulometry distribution of the sand.
Bibliographic Reference: EUR 14013 FR (1992) 51 pp., FS, ECU 7.50
ISBN: ISBN 92-826-3980-0
Record Number: 199210578 / Last updated on: 1994-12-02
Original language: fr
Available languages: fr