The strength and economic benefit of soil stabilization with Palm Oil Fuel Ash (POFA) as agro-waste

¹ Doctoral Student, Civil Engineering Department, Faculty of Engineering, Universitas Andalas, Padang, Indonesia
² Civil Engineering Department, Universitas Abdurrab, Pekanbaru, Indonesia
³ Civil Engineering Department, Universitas Andalas, Padang, Indonesia

^* Corresponding author: ahakam@ft.unand.ac.id

Abstract

Soil stabilization is most effective method to increasing the strength of poorly soil. In generally, adding cement is preference that other but it is not environmentally friendly. Due to the production process of cement more released the carbon dioxide in the atmosphere. Alternative stabilization method can use agro-waste from palm oil milling is called POFA, which having pozzolanic properties such as cement. The purpose of this study to find how much the increasing soil strength when add 20% treated POFA and how the economic benefits in replacing cement. Soil strength testing utilize an unconfined compression test (UCT) and economic benefits by reviewing previous research on soil-cement stabilization. Based on compaction standard that added 20% treated POFA was decrease the maximum dry density (MDD) and increase the optimum water content (OMC). The Soil-treated POFA stabilization gained the maximum compressive strength after curing for 28 days. Exhibit the increasing of compressive strength from 0.55 MPa to 1.04 MPa. The economic advantage with add of 20% treated POFA was able to replace the cement between 5% - 7.5%. Thus, treated POFA is feasible to be used as a soil stabilization material by considering the curing times.