Experimental Study of Natural Materials Utilization as a Stabilization Agent on Soft Soil

Abstract

Chemical soil stabilization is known as the most economical method compared to others. The development of stabilization materials has led to studies of the utilization of natural materials and waste materials to replace cement and lime which has become the most popular binder agent ever known. This research utilizes natural minerals such as overboulder, zeolite and Palm Oil Fuel Ash (POFA) as its binder agents. The amount of natural material varies at intervals 3%-15% by the weight of soil. Additional of natural materials is done to increase bearing capacity as a subbase layer, which is based on FHWA standards CBR minimum is 20%. California Bearing Ratio (CBR) tests were carried out to see the effect of each material for increase bearing capacity of soft soil. Curing periode is varies at 7 days, 14 days and 28 days. The results shows, by adding natural minerals such as overboulder, zeolite, and POFA increasing the CBR value up to 5 times, 6 times and 5 times compared to untreated soil and close to the CBR value of cement stabilized soil. Referring to FHWA standards, we can conclude that natural materials can be used for stabilization materials on subbase layer.