A real-time electrical resistivity-based framework for assessing the effectiveness of concrete curing

Curing is crucial for maintaining moisture and temperature after pouring to promote hydration. Failure to cure promptly affects the hardening and durability of concrete; however, current concrete specifications often provide only qualitative guidance on when to begin curing. This study establishes a real-time method for quantifying the effects of curing and curing delays on concrete properties, addressing the lack of quantitative tools for assessing curing effectiveness. This work used three environmental exposure levels (evaporation rates: 0.15, 0.55, and 0.85 kg/m²/h) and tested concrete and mortar samples for electrical resistivity, internal temperature, and porosity. Continuous wet curing reduced the internal concrete temperature by approximately 15 °C compared with air curing under severe drying conditions. This work shows that wet curing can be delayed up to 6 h at low evaporation (0.15 kg/m²/h) and 3 h at moderate evaporation (0.55 kg/m²/h) but must be applied within 2 h at high evaporation rates (0.85 kg/m²/h) to avoid unrecoverable damage. Longer delays statistically increased surface porosity from approximately 19% in well-cured specimens to approximately 24% in air-cured specimens and led to permanent changes in the microstructure. Developed a framework to quantify the effectiveness of wet curing on concrete. Tested three evaporation rates: 0.15 kg/m²/h (low), 0.55 kg/m²/h (moderate), and 0.85 kg/m²/h (high). Evaluated internal concrete temperature, resistivity, and porosity over 72 h. Allowable delays: 6 hours (low), 3 hours (moderate), < 2 hours (high evaporation). Longer delays resulted in irreversible microstructural changes and increased porosity.