Optimizing fiber parameters coupled with chemical treatment: PROMETHEE Approach

In order to combat issues related to expansive soils, chemical stabilization augmented with use of synthetic fibers is gaining focus in recent times. However, in most of these applications, the practicing field engineers face difficulty in selecting the right mix of fiber size, fiber dosage and stabilizer content. The decision becomes more typical, as the target is to achieve or enhance multiple geotechnical properties which differ with fiber dosage and stabilizer content based on governing mechanisms. Addressing these issues, in this study an attempt is made to present an approach for selecting fibre dosage and lime mix for a typical expansive semi-arid soil. In this article, the effect of randomly oriented polypropylene fiber inclusion in enhancing various geotechnical properties of a typical expansive semi-arid soil is studied. The addition of lime is considered in order to ensure proper bonding between clay particles and discrete fiber elements. PROMETHEE is adopted in order to assist in multi-criteria decision-making process. The approach evaluates multiple geotechnical properties for possible alternatives viz., untreated soil; lime treated soil and other including combinations of fiber dosage and fiber size in the presence of lime. The response measures being the targeted geotechnical properties which include, linear shrinkage tests, unconfined compression strength test, California Bearing Ratio behavior, compressibility characteristics and hydraulic conductivity. The study revealed the best possible alternative considering all the selected response measures.