Decision-Making Model for Soil Stabilization: Minimizing Cost and Environmental Impacts

Studies have examined the environmental impacts of soil stabilization; however, the costs of distinct dosages in such methods remain unexplored. Indeed, it is not yet clear whether there is a trade-off between cost and environmental impacts for soil stabilization dosages. This technical note seeks to address this gap by performing an economic analysis of three dosage strategies (high binder/low dry unit weight, medium binder/medium dry unit weight, and low binder/high dry unit weight) considering five values of a porosity-binder index and strength and stiffness as performance parameters. Such results are then combined with environmental impact data to create a decision-making model for optimal dosages considering the economic and environmental dimensions of sustainability. An example of a road base (q(u) = 1,034 kPa) is presented to illustrate how the model can be applied in real-world projects. This q(u) corresponds to a porosity-binder index of 32.44, which can be attained by different combinations of dry unit weight and binder content ranging respectively from 16-19 kN/m(3) to 3%-7%. The proposed model makes it possible to determine the dosage with minimal cost and environmental impacts: a lime content of 3% and dry unit weight of 17.44 kN/m(3). The binder was found to be the main contributor to cost and environmental impacts, indicating that dosages with minimal binder content and maximum dry unit weight should be preferred. The findings presented suggest that there is no trade-off between environmental and economic pillars, and dosages with minimal cost and impacts can be created. (C) 2020 American Society of Civil Engineers.