Assessment of the pozzolanic activity of supplementary cementitious materials through electrical conductivity: a systematic methodological review with a scientometric approach

This study presents a systematic methodological review supported by a scientometric approach on the use of electrical conductivity (EC) to assess the pozzolanic activity of supplementary cementitious materials (SCMs). The increasing demand for sustainable alternatives to Portland cement has intensified the development of new SCMs, reinforcing the need for rapid and reliable methods to evaluate their reactivity. Electrical conductivity-based tests have gained attention due to their simplicity, low cost, and sensitivity to ionic variations during pozzolanic reactions; however, their methodological consistency and interpretative robustness remain debated. A total of 103 articles published between 1989 and 2025 were systematically selected from the Scopus and Web of Science databases. Scientometric analyses were employed to characterize the temporal evolution of the field, its main contributors, journals, collaboration networks, and influential documents. In parallel, the 20 most cited studies were examined in depth to identify experimental parameters, testing configurations, and data treatment strategies. Multivariate analyses, including Principal Component Analysis and Multiple Correspondence Analysis, were applied to reveal recurrent quantitative and qualitative methodological patterns. The results indicate sustained growth in scientific production, combined with pronounced heterogeneity in EC testing protocols. This variability helps explain recurrent inconsistencies reported in the literature, particularly discrepancies with mechanical performance, limitations of blank correction procedures, uncertainties regarding reaction mechanisms, and atypical conductivity behavior under high calcium hydroxide contents. Overall, EC is confirmed as a valuable tool for rapid screening and early-stage assessment, although its use as a standalone indicator of pozzolanic activity remains limited.