The effects of chemical attacks on physical and mechanical properties of concrete produced under cold weather conditions

摘要

This study investigates the effects of corrosive conditions on the physical and mechanical properties of concrete produced in cold weather. 30% calcium nitrate and 5% hydroxyethylaminemixture (HEA) were used as additives in antifreeze. Within 15 min of placing the prepared concrete samples in molds, the samples were put in a deep freezer. They were exposed to frost at 0℃, -5℃, -10 ℃, -15 ℃ and -20 ℃ degrees in the deep freezer over two days. The samples were taken out of the freezer and removed from the forms one day later. They were cured in water at room temperature until the 28th day. The samples were then exposed to sulfuric acid of 5% concentration (H_2SO_4), magnesium sulfate of 7500 mg/L concentration (MgSO_4), sodium sulfate of 5% concentration (NaCl), and corrosive cure and water-curing until the 120th day. At the end of the curing period, the permeable pore space volume, water absorption ratio, unit volume weight, capillarity ratio, impermeability, compressive strength, static modulus of elasticity, Poisson's ratio and tensile strength values of the concrete samples were determined. The results showed that the physical and mechanical properties of the concrete were negatively affected by the corrosive conditions.