This work consisted in determining the geotechnical properties of the
soil of the Cubitermes termite mound soil treated with lime for use in
road construction in accordance with the relevant standards. The raw soil is
composed of 29.45% clay, 45.12% silt and 25.43% sand, and its granulometric curve is above the relevant standard curve.
The addition of lime up to 9% decreases the fine fraction content from 75% to
60%, and the maximum dry density from 1.62 t/m3 to 1.36 t/m3.
The reduction of the fine fraction should reduce the soil sensitivity to water,
and the emission of dust from the road. The compressive strength of the raw
soil (3.89 MPa) is higher than that of most cohesive soil, and is probably one the causes of the longevity of the rural
road paved with this soil. Treated soil with 6% in lime content has the highest
compressive strength (5.95 MPa), and the lowest deformation at failure. Until
28 days, the improvement of the compressive upon the curing time is almost the
same for untreated and treated termite mound soils. Thus, this improvement could
be mostly attributed to the drying of the samples instead to the pozzolanic reactions. Besides, adding
lime also enhances the shear strength of soil.
Therefore, adding lime up to 6% in content to the termite mound soil should
improve its behavior as surface roads.
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