The present work investigates the influence of curing conditions on the mechanical and physical properties of heavyweight concrete. The prismatic bars of 40 mm × 40 mm × 160 mm dimension were cured in a climatic chamber (relative humidity 30%, average temperature 26°C), wet (100% of humidity, average room temperature 26°C) and CO2 chamber-wet (relative humidity 90%, average temperature 50°C and average CO2 concentration 20 %) conditions for 2, 7, 28 and 90 days. Density, compressive strength, dynamic modulus of elasticity, and longitudinal shrinkage were determined at different ages of curing. Mercury Intrusion Porosimetry was used to analyze and determine the influence of carbonation on pore structure evolution. Samples cured under CO2-wet conditions showed a higher compressive strength (54.05, 66.83, 84.98, 96.35 MPa) compared to that of the samples exposed to wet (45.49, 65.87, 78.91, 93.80 MPa) and dry (39.62, 46.52, 48.45, 45.28 MPa) conditions at all ages. The dynamic modulus of elasticity of CO2-wet cured samples (53.02, 51.48, 59.24, 67.60 GPa) was lower than that of samples cured in wet conditions (59.82, 66.76, 78.84, 80.27, GPa), but higher than that of dry-cured samples (45.74, 45.73, 43.91, 44.62 GPa). The density of the samples exposed to all curing conditions was higher than 3800 kg/m3. Carbonation led to a decrease in total porosity (from 10% to 20%) and an increase in density (from 320 to 390 kg/m3). Also, the time and curing conditions have strongly influenced the pore structure. The precipitation of calcium carbonate in the matrix of concrete and the acceleration of hydration reaction under wet conditions has led to a decrease in porosity.
