When confronted with the structural design of any civil engineering, the first and arguably the most crucial decision engineering teams must undertake is the selection of both an apt material and the fitting structural typology for its components. Each component must adhere to the technical and functional standards set forth by both standards and stakeholder requirements. Nevertheless, sustainable design necessitates a balancing act among economic, environmental, and social impacts, which form the three fundamental pillars of a sustainable framework. Merely selecting a solution solely based on economic considerations, which are most frequently considered in decision-making processes, may not invariably yield a sustainable outcome.
Utilizing a case study approach, this paper aims to outline a systematic methodology for selecting concrete structural components, which takes into account the social, economic, and environmental impacts of the decision. A comprehensive list of sustainability criteria for selection of concrete structural components is presented and discussed in detail. The selected sustainability criteria are then applied to identify the most sustainable solution illustratively, among three comparable composite concrete structural alternatives at the material and component level, respectively: (1) natural aggregate concrete (NAC, Column A), (2) fully recycled aggregate concrete (FRAC, Column B), and (3) ultra-high performance concrete (UHPC) - FRAC composite concrete (Column C). TOPSIS (Technique for Order Preference by Similarity to the Ideal Solution) algorithm, a method based on the concept that the best alternative to MCDM (multi-criteria decision making) problems is that which is closest to its ideal solution, is used to rank different alternatives. AHP (Analytic Hierarchy process-technique), a structured technique for analyzing MCDM problems according to a pairwise comparison scale, is used to identify the global relative importance weights for different sustainability criteria. The findings show that the most sustainable alternative is the UHPC-FRAC composite concrete column, which is actually a novel option that is seldom used in practice. The developed model inherently aids engineering teams in comprehending the impact of fundamental decisions undertaken during the design phase of individual structural components.