cement, lime soil, cane pulp ash has been done. However, study of clay
stabilization soil is still interesting subject to be investigated. This research
investigated capability of fly ash, as a waste material, with the addition of cement
as pozzolanic material, combined with clay soil, to increase the shear strength and
cohession of these clay.
The research was divided into 2 steps of test. The first was to find the
OMC (Optimum Moisture Content) condition of clay. This step covered clay
characteristics test (water content test) and standard proctor test (compaction
method). The second step was Unconfined Compression test (UCS). This test was
to find the optimum shear strength and cohession of clay that was stabilized with
fly ash and cement. The percentage of cement which added were 0%, 8%, 12%,
and 16%; and the percentage of fly ash which added were: 0%; 12%, 24%, and
36%.
The results of the research were: clay reach the optimum moisture content
when added with 901.54 ml of water, and reach the optimum shear strength and
cohession when added with cement as much as 8% of percent and fly ash as much
as 12% of percent. Addition of cement and fly ash above that percentages were
useless. Another results were shear strength and cohession reach the optimum
value on 14th day of curing time rather than 1st day and 7th days of curing times.