Unsaturated behaviour of soils stabilized with fly ash from coal combustion
DOI:
https://doi.org/10.14195/2184-8394_160_3Keywords:
soil stabilisation, unsaturated soils, alkaline activationAbstract
The influence of suction on the mechanical behavior of chemically stabilized soils has not yet been consistently quantified, a situation also motivated by difficulties in the experimental procedure to characterize the unsaturated response. This paper presents retention curves obtained for a soil stabilized with Portland cement or an alkaline cement. Triaxial tests are also presented, for the same curing conditions, up to 90 days. Previous attempts to characterize retention curves for soil - (alkaline) cement are unknown; the results obtained showed that the pore structure is formed at 28 days, before the development of the gel matrix responsible for the increase in strength. The retention curve changed after stabilization, with different shapes for each binder – Portland generated a higher air entry value and a narrower suction range. The differences between curves for each binder suggest a methodology to evaluate the quality of stabilization by alkaline cement.
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