1 research outputs found
Laboratory alteration of gypsiferous materials below a landfill
11 pages, 8 figures, 4 tables.Some urban solid waste landfill sites in Spain are located on geological substrates of gypsiferous lithology.
Although this type of substrate is assumed to be of low permeability, it can develop secondary
pores by dissolution and, under favourable environmental conditions, form a karstic system that
may pose serious geotechnical problems in the medium and long term. The purpose of this work
was to study alterations caused by selective tests in various sections of a gypsum lithological column
obtained from the Colmenar de Oreja landfill site (Spain). The tests were used to assess the influence
of individual environmental factors and involved the addition of milli-RO water, solutions containing a
1%, 5% or 10% concentration of landfill leachate, and 2, 5, 10 and 15 mg l 1 solutions of NaCl in successive
immersion鈥揹rying cycles at 15, 20 or 60 C. Differences in alterability between the six studied
segments of the lithological column were found to be due to differences in lutite content, specific
crystal habit and type of cement. Segments with specular gypsum were the strongest in the tests,
while the segment with the highest amount of detrital materials was the most responsive to temperature
and moisture changes. The treatments that produce greater alterations are those that contain
only milli-RO water.This work was supported by Comunidad Aut贸noma de Madrid (CAM) under Project COR0062/94.Peer reviewe