Integrated Methodological Framework for Chloride-Induced Corrosion Assessment in Geopolymer Concrete: A Systematic Secondary-Data Study

Background: Chloride-induced reinforcement corrosion threatens the durability of reinforced concrete, while existing methods for assessing chloride transport and reinforcement corrosion in geopolymer concrete remain fragmented. Objective: This study aims to characterize the distribution of assessment methods, identify methodological gaps, and develop an integrated framework linking material characteristics, chloride transport, electrochemical responses, and reinforcement damage. Methods: A quantitative-descriptive systematic secondary-data approach was employed, incorporating Scopus-based literature screening and methodological coding. Of the 1,792 records identified, 973 duplicates were removed, leaving 819 records for screening. Following eligibility assessment and final quality control, 139 reports were retained, including 88 unique core methodological studies that were analyzed using 20 binary indicators. Results: Compressive strength was assessed in 65 studies (73.9%), scanning electron microscopy (SEM) or field-emission scanning electron microscopy (FESEM) in 55 (62.5%), chloride profiling or diffusion analysis in 36 (40.9%), half-cell potential (HCP) or open-circuit potential (OCP) measurements in 25 (28.4%), and linear polarization resistance (LPR) or corrosion current density ((I_{\mathrm{corr}})) measurements in 20 (22.7%). Reinforcement mass loss was measured in only 9 studies (10.2%). Comparisons with ordinary Portland cement (OPC)-based concrete were reported in 31 studies (35.2%), whereas numerical values for concrete cover thickness were documented in only 16 (18.2%). These findings reveal substantial methodological fragmentation, particularly in the integration of electrochemical monitoring with physical damage validation. Conclusion: The proposed framework integrates precursor chemistry, alkali activation, microstructural characteristics, chloride transport, steel depassivation, electrochemical responses, reinforcement mass loss, and mechanical degradation. It provides a structured basis for improving methodological consistency and experimental comparability, although further experimental validation is required.