Comparison of properties of traditional and accelerated carbonatedsolidified/stabilized contaminated soils
LIU Jiangying , XU Dimin , XIONG Lan , Colin HILLS , Paula CAREY , Kevin GARDNER
DOI:
Received July 16, 2007,Revised October 15, 2007, Accepted , Available online
Volume 20,2008,Pages 593-598
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The investigation of the long-term performance of solidified/stabilized (S/S) contaminated soils was carried out in a trial site in
southeast UK. The soils were exposed to the maximum natural weathering for four years and sampled at various depths in a controlled
manner. The chemical properties (e.g., degree of carbonation (DOC), pH, electrical conductivity (EC)) and physical properties (e.g.,
moisture content (MC), liquid limit (LL), plastic limit (PL), plasticity index (PI)) of the samples untreated and treated with the traditional
and accelerated carbonated S/S processes were analyzed. Their variations on the depths of the soils were also studied. The result showed
that the broad geotechnical properties of the soils, manifested in their PIs, were related to the concentration of the water soluble ions and
in particular the free calcium ions. The samples treated with the accelerated carbonation technology (ACT), and the untreated samples
contained limited number of free calcium ions in solutions and consequently interacted with waters in a similar way. Compared with the
traditional cement-based S/S technology, e.g., treatment with ordinary portland cement (OPC) or EnvirOceM, ACT caused the increase
of the PI of the treated soil and made it more stable during long-term weathering. The PI values for the four soils ascended according
to the order: the EnvirOceM soil, the OPC soil, the ACT soil, and the untreated soil while their pH and EC values descended according
to the same order.
