Reduction of Plasticity index and Unit Weight from Soft Clay Soil Through Stabilization with Expanded Polystyrene (EPS) and Residium Cracking Catalyst 15 (RCC 15) for Lightweight Embankment
M Rio Eka Shaputra (a*), Syahril S (a), Indra Noer Hamdan (b), Fahrul Rizky (a)

a) Magister of Applied Infrastructure Engineering Program, Departement of Civil Engineering, Bandung State of Polytechnic, Bandung Barat, Indonesia
b) Department of Civil Engineering, Faculty of Engineering, National Institute of Technology Bandung, Indonesia

Abstract

In connection with the increasing growth of motorized vehicles, it must be followed by the development of supporting infrastructure. In the implementation stage of infrastructure construction, the self-load of the construction plays an important role when the construction is carried out on soil types with unfavorable conditions such as soft clay. Load reduction techniques can be carried out using lightweight embankments. Lightweight embankment is a type of embankment that uses soil replacement material so as to reduce the specific gravity of the soil. Soil replacement can be done by stabilization method using Expanded Polystyrene (EPS) as a lightweight material. EPS which is polymetric foam granules with plastic base material has a high shear value so that a binder is needed to bind each EPS particle and soil. The use of Spent Catalyst Residium Catalytic Cracking 15 (RCC 15) as a binder can provide binding force between EPS particles and soil. RCC 15 has the same silica content as cement so that RCC 15 can be an alternative in replacing cement at a lower price. The production of RCC 15 from PT Pertamina can reach 20 tons per day so that the use of RCC 15 has the potential as a method of reducing waste. The research was conducted using a mixture of 0.4% EPS and a mixture variation of 20%, 25% and 30% RCC 15. Testing was carried out using the index properties testing method. Changes in the PI value that occurred in the ER-3 sample against the initial soil resulted in a decrease of up to 11.46% which shows that the soil characteristics are getting better. Specific gravity testing shows that the use of EPS as a soil replacement material can reduce the specific gravity of the soil.

Keywords: soil stabilization, plasticity index, lightweight embankment, expanded polystyrene, spent catalyst RCC 15

Topic: Soil sciences