Currently, foundation piles for inhabited areas are often constructed using a continuous flight auger, which is a cost-and timeefficient technology that does not require stabilization of the borehole wall; the steel bar reinforcement is embedded after the concrete has been poured. However, this reinforcement operation can lead to severe construction and structural issues. Thus, several improvements to this technology have been proposed since its first application in the 20th century, such as the use of more fluid concretes. Nevertheless, steel and polymers are emerging as a potential replacement for steel bars in concrete reinforcement for several types of structures and building components, with identified and quantified benefits from a sustainability perspective. Accordingly, this paper proposes and validates a multicriteria decision-making approach designed with multidisciplinary experts within the construction field to assess the sustainability index of concrete pile foundations. The results of a case study enable us to conclude that polymeric fiber-reinforced concrete piles are the most sustainable due to their cost-structural efficiency ratio, high durability, and minimal risks during construction. Steel fiber-reinforced concrete alternatives were also found to be more sustainable than traditional reinforced concrete. Nonetheless, these results are unrepresentative of the current practice as direct costs were found to be the main driver in the decision-making processes, while other costs and both environmental and social indicators are disregarded. This justifies the urgency to provide sustainability-driven decision-making approaches capable of objectively quantifying the satisfaction degree of economic, environmental, and social indicators involved in the analysis.

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