Sustainable material selection using complex type 2 intuitionistic fuzzy analytic hierarchy process

Sustainable material selection has become a crucial challenge in the construction industry due to increasing environmental concerns, resource limitations, and the demand for long-term ecological balance. Traditional evaluation approaches often struggle to adequately address the complexity and uncertainty inherent in expert judgments. To overcome these limitations, this study proposes a novel decision-making framework based on the Complex Intuitionistic Type-2 Fuzzy Analytic Hierarchy Process (CIT2F-AHP). The method integrates the strengths of fuzzy set theory and analytic hierarchy process to capture both magnitude and phase information, enabling a more robust representation of expert opinions under uncertainty. A comprehensive set of evaluation criteria covering environmental, technical, economic, social, and regulatory aspects is adopted for assessing sustainable alternatives. The proposed approach is applied to compare low-carbon cement and concrete options, including carbon-cured concrete, geopolymer concrete, alkali-activated binders, and limestone calcined clay cement. The findings highlight the effectiveness of CIT2F-AHP in ranking sustainable materials and demonstrate its potential as a reliable decision-support tool for practitioners and policymakers in advancing green construction practices.