Electrochemical impedance spectroscopy and ultrasound for monitoring expansive reactions and their interactions on cement composites

•Incipient formation of ASR and DEF expansive products was studied.•EIS was applied to monitor ASR, DEF and couple attack over time.•EIS was supplemented by ultrasonic pulse velocity and microstructural analyses.•DEF was detected by EIS investigation after just three months of exposure.•The distress occurrence was evaluated before they visually appear. The study presented in this paper proposes a non-destructive methodology to monitor the incipient formation products from expansive and deleterious reactions such as ASR and DEF and their evolution over time. These formations can enhance internal stresses in voids promoting dimensional variation, stress–strain, and cracking. The study was based on the monitoring of electrochemical impedance spectroscopy (EIS) and open circuit potential (OCP) combined with ultrasonic pulse velocity and microstructural analyses. It was verified potential results of these complementary methodologies to monitor reinforced structures subjected to expansive mechanisms, being useful to evaluate the occurrence of pathological evidences before they visually appear.