Multi-phase forensic characterization of durability failures: a case study on pathological investigation of chemical, physical, and hygrothermal distress in concrete infrastructure

Concrete structures deterioration due to environmental exposure, moisture dynamics, and material composition deficiencies remains a critical challenge in infrastructure durability. This study presents a multi-phase forensic characterization of concrete durability failures at the University Campus, NUST H-12 Islamabad Pakistan, employing an integrated methodology that combines microscopic crack analysis, Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS), X-Ray Diffraction (XRD), and moisture content evaluation to investigate three distinct degradation mechanisms under Pakistan’s climatic conditions. Results revealed that plastic shrinkage in Plain Cement Concrete (PCC) pavement resulted from excessive evaporation and inadequate curing, with measured crack widths averaging 2.4 mm. Efflorescence and carbonation were confirmed through XRD detection of calcium carbonate (CaCO3), indicating portlandite dissolution due to moisture ingress and alkalinity reduction from pH 12.5 to 9.2. Sulfate attack was validated by SEM-EDS detection of ettringite formations and 5.94% moisture content, revealing expansion-driven cracking accelerated by inadequate damp-proof course systems. The forensic framework established correlation coefficients of 0.87 between moisture content and degradation severity, providing practitioners with quantitative assessment tools. These findings enable targeted remedial strategies through optimized mix designs incorporating Supplementary Cementitious Materials (SCMs) to enhance long-term resilience in climate-sensitive urban infrastructure.