Sulfate soils stabilization with magnesium-based binders
Fecha
2016Autor
Versión
Acceso abierto / Sarbide irekia
Tipo
Artículo / Artikulua
Versión
Versión aceptada / Onetsi den bertsioa
Impacto
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10.1016/j.clay.2016.10.033
Resumen
Sulfate soils' stabilization is a very interesting subject with technical, economic and environmental implications.
The difficulty of their stabilization is due to the fact that the usual stabilizer additives are based on calcium. In
these soils, sulfate combines with the calcium from the additive and the aluminum from the clay, resulting in a
highly hydrated expansive mineral named ettringite ...
[++]
Sulfate soils' stabilization is a very interesting subject with technical, economic and environmental implications.
The difficulty of their stabilization is due to the fact that the usual stabilizer additives are based on calcium. In
these soils, sulfate combines with the calcium from the additive and the aluminum from the clay, resulting in a
highly hydrated expansive mineral named ettringite. This provokes the swelling of the treated material and
even its destruction. This study analyzes the result of the substitution of the calciumbased additives by one alternative
additive based on magnesium, an industrial byproduct named PC-8, in the stabilization of five different
sulfate soils. From a mechanical point of view soils treated with PC-8 reached similar resistance values to the
lime treated ones, of about 2–3 MPa for 4% dosage and 2–5 MPa for 8% dosage, being usually better with the
PC-8 results than with the lime ones. When PC-8 was combined with GGBS the resistance values increased up
to 11–13 MPa and the lime-GGBS reached the 6–7 MPa. The natural swelling of the soils treated with PC-8 decreased
substantially and maintained constant even for immersion at long-term. In the case of the soils treated
with lime, long-termswelling increased up to very high values even in the case of soilswithout natural swelling.
XRD analysis of these samples demonstrated the existence of ettringite in 4 of the 5 soilswhen theywere treated
with lime and there was not expansive minerals in the PC-8 treated soils, agreeing with the swelling observed
behavior of the soils when treated with both additives. [--]
Materias
Sulfate soil,
Soil stabilization,
Valorization,
Construction material,
Ettringite
Editor
Elsevier
Publicado en
Applied Clay Science, volume 135, january 2017, pp. 457-464
Departamento
Universidad Pública de Navarra. Departamento de Proyectos e Ingeniería Rural /
Nafarroako Unibertsitate Publikoa. Landa Ingeniaritza eta Proiektuak Saila
Versión del editor
Entidades Financiadoras
This research has been supported by research project OTRI
2011021091 with Magnesitas de Navarra S.A. Company.