Behavior of soil-bentonite and soil-cement-bentonite mixes for use in vertical cutoff walls
DOI:
https://doi.org/10.24849/j.geot.2016.136.06Keywords:
Triaxial tests, Barriers, Soil-Cement-Bentonite (SCB) mixtures, Hydraulic conductivityAbstract
Vertical cutoff walls are a quick and effective solution in solving geotechnical and environmental problems concerning containment of subsurface contamination. With the objective of studying the behaviour of materials suitable to use as a fill for these barriers, undrained triaxial tests (CIU) and hydraulic conductivity tests were carried out in soil-bentonite (SB) and soil-cement-bentonite (SCB) mixtures. Different water-cement ratios, water contents and confining pressures were analysed, as well as three different bentonite contents for SCB mixes and two for SB mixes. The global analysis of the results allowed identifying changes in mechanical behaviour and hydraulic conductivity due to parameter variation. The results of the CIU tests indicated that for the same bentonite content, decreasing the water/cement ratio resulted in an increase in material strength parameters. For a w/c ratio of six, increasing the bentonite content also caused an increase in material strength parameters. Results of hydraulic conductivity tests revealed that SCB mixes had higher hydraulic conductivity than SB mixes.
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