Chemical stabilization has been extensively used for the improvement of soft
clay soils, in enhancing the shear strength and limiting the deformation behaviours.
Cement is widely used as a stabilizing material for soils, but the increasing price is
causing economic concerns among practitioners and clients alike. The quest for
alternative cheaper stabilizing agents is therefore more urgent than before. Rice husk is a
major agricultural waste in Malaysia and the common disposal method of open burning
has notoriously contributed to environmental pollution. The possibility of admixing rice
husks with cement for stabilizing soft soils could be a solution to both problems. This
study was aimed at assessing the usefulness of cement-rice husks as an effective soil
stabilizer for improving the mechanical properties of clay soils. Laboratory experiments
were carried out on a stabilized soft clay to study the inter-relationships between shear
wave velocity, one-dimensional compressibility and unconfined compressive strength.
Bulk clay samples were collected from the Research Centre for Soft Soils (RECESS) of
UTHM. The stabilized specimens were prepared with the clay admixed with 5 % and 10
% cement and various quantities of rice husks, then compacted into cylindrical
specimens measuring 38 mm in diameter and 76 mm high. The specimens were then left
to cure for different periods up to a month. The stabilized specimens were observed to
undergo increase in stiffness and strength, as well as significant reduction in
compressibility, highlighting the great potential of cement-rice husk as an alternative
soft soil stabilizer.
Keywords: Clay soil stabilization, cement, rice husk, shear wave velocity, onedimensional
compressibility,
unconfined
compressive
strengt