VOLUME CHANGE AND COMPRESSIVE STRENGTH OF COMPACTED LATERITIC SOIL UNDER DRYING-WETTING CYCLE REPETITION

Abstract

This study was conducted to investigate volume changes and compressive strength behavior of
compacted high expansive soils from lateritic soils (60%) and bentonite (40%) mixture under drying-wetting
cycle repetition as a construction materials alternatives. Lateritic soil obtained from waste Nickel mining site
in East Halmahera, North Maluku, Indonesia. Laboratory tests of physical properties using ASTM standard
test were conducted to lateritic soil, bentonite, and mixture soil, while SEM test for lateritic and mixture soil.
The soil samples have optimum moisture content based on Proctor standard compaction test results (28%).
Then, samples were treated drying-wetting cycle and repeating four cycles with 25, 50, 75, and 100% series
path. The soil suction measurement used the Whatman #42 filter paper placed at the top, middle, and bottom
of each sample, and after that, the unconfined compression strength test was performed based on the ASTM
standard. The experimental results showed that the drying-wetting cycle repetition has a significant effect on
volume change, suction, and compressive strength of the soil. The increasing number of cycle causing void
ratio decrease and degree of saturation increase, and soil suction tend to decrease at the certain void ratio;
likewise, soil compressive strength decreases at particular water content. Decreasing soil compressive strength
causes a decrease in elastic modulus so that soil failure behavior is more brittle and work-softening. Therefore,
the study results provide important geotechnical characteristics data of lateritic soil with high swell-shrink
potential. Henceforth, some soil improvement innovations can perform to generate high-quality construction
materials more effectively and efficiently.