الملخص الإنجليزي
Expansive soil is a problematic soil that expands when water is added and shrinks when water
evaporates. The process of swelling and shrinking leads to the excessive appearance of cracks and
weakens the soil structure with time. using waste material is the primary objective of this research
in order to achieve a cost-effective solution. it involved to using waste marble powder and cement
to stabilize the expansive soil in the Al-Khoud region. Laboratory tests were conducted on soil
samples before and after stabilization. The tests are wet sieve analysis, hydrometer, specific
gravity, atterberg limit, compaction, swelling percent, consolidation, free swell index, unconfined
compressive strength, suction, XRD, XRF, and SEM. The results revealed that the percentage of
fines in the untreated expansive soil is 74% and are silty clays of high plasticity. The compacted
soil has a maximum dry density of 1.54 g/cm3 at an optimum water content of 21.8%. The swelling
percentage of untreated expansive soil was 15.7%, and the modified free swell index was 4.02.
Several binder proportions of marble and cement were added to the soil. Marble percentages of
10, 15, 20, 30, 40, 50, 60, and 80% were added. Different marble proportions were mixed with 5%
cement, and the results demonstrated that the swelling percentage of marble 60% (MP60) is 3.9%,
nearly equivalent to cement 5% (C5), which is 3.4%. Unconfined compressive strength test (UCS)
was 1212 KN/m2 for untreated soil and all samples were cured for 7, 14, and 28 days. 5% cement
(C5) 7-day curing can be replaced with 30% marble (MP30) cured in 28 days. The longer the
curing duration, the stronger the sample. XRD results for untreated expansive soil showed the
existence of clay minerals such as montmorillonite and illite, while The XRD results for treated
samples show a lack of clay minerals. The suction test showed that adding 30% marble and 5%
cement (MP30C5) to the soil significantly reduced the suction amount. The SEM image of treated expansive soil with cement and marble showed better bonding and denser surface than untreated expansive soil.
