Characterization of pore systems of air/water-cured concrete using ground penetrating radar (GPR) through continuous water injection

This paper describes a series of experiments in characterizing the pore systems of mature and hardened air-cured and water-cured concrete specimens. The characterization was achieved by measuring the real part of complex permittivity (ε′) and energy attenuation (dB/m) through continuous injection of pressurized fresh water over a period of 48 h in each test run. The measurements were based on coupling a 1 GHz Ground Penetrating Radar (GPR) on the surfaces of concrete specimens. At different degrees of water saturation (Sw) received by the specimens, the air-cured and water-cured concrete specimens were characterized by recognizing different patterns depicted in the plots of ε′ vs Sw and dB/m vs Sw. These differences in patterns are attributed to the pore size distributions, as a result of different curing histories.