ARABIAN JOURNAL OF GEOSCIENCES, cilt.15, sa.480, ss.1-11, 2022 (SCI-Expanded)
This study investigates the efect of waste zeolite (waste zeolite) and lime-waste zeolite mixtures on swelling potential,
mechanical, and durability performances of a high plasticity clayey soil considering the macro and micro aspects. Three
diferent subtypes of the tufte formation were taken into account to examine the efect of diferences of tuf structure on
the stabilization performance. Within this scope, XRD, XRF, and SEM analyses were performed to identify mineralogical
and oxide components of the materials. Computed tomography (CT) and scanning electron microscope (SEM) images were
evaluated during the inner structure examination. The correlation between unconfned compressive strength and Hounsfeld
unit (HU) obtained from the CT images was investigated statistically. Pearson’s correlation analysis and Spearman’s Rho
were performed to measure the strength of association between two variables. The swelling and mechanical properties of the
stabilized soils were evaluated. Durability performances of the stabilized samples were determined considering unconfned
compressive strength and the HU values of the samples subjected to freezing–thawing (F-T) cycles. The efects of curing
and F-T cycles on the volume of the samples were investigated using CT imaging. The unconfned compressive strength of
the natural soil at the end of the 28-day curing period was determined as 118.46 kPa, and the SLW10 sample containing
natural soil+6% lime+10% white tuf waste was determined as 1651.59 kPa. The highest strength after the F-T cycles was
obtained from the SLG10 sample containing soil+6% lime+10% green tuf waste as 1382.05 kPa. From the statistical
analyses determined that there is a signifcant, positive correlation between HU value and unconfned compressive strength
(r=0.99, p<0.01). As a result of the study, it was determined that waste zeolites decreased swelling pressure, and the onedimensional swelling percentage of clayey soil increased unconfned compressive strength and durability performances of
soil on a limited scale. On the other hand, no swelling behavior was observed in the soils stabilized with lime and limewaste zeolite mixtures. Mechanical and durability performances of waste zeolite-lime mixtures are more efective than
lime-stabilized soils. Strength and durability performances of soils can be estimated accurately considering HU values. In
the light of the data obtained from the experimental study, the relationship between unconfned compressive strength and
HU values showed that CT is a useful method in the analysis of soil microstructure and nondestructive strength evaluation.