Effect of antifreeze admixture on durability of concrete

The purpose of this study is to determine the effect of the antifreeze, which are used as the concrete admixture, on the durability of the concrete. Three groups of concrete samples C30 class were prepared such as the mixture of 30% of Calcium nitrate and 5% of hydroxy epoxy amine (%30KN+%5HEA) used for the concretes produced in cold air to prevent the effect of freezing, calcium nitrate (KN) and anti-freeze extenders containing polyhydroxy amines (PHA). These samples were freshly put in the freezer in 15 minutes after the mixing process. They were exposed to freezing effect for 48 hours at 0, -5, -10, -15 and -20 degrees. After 48 hours, there was practiced a 28-day-pressure resistance test on the concerete samples left in water cure. There were identified a quantity of antifreeze resistance providing the best pressure resistance for all kinds of anti-freezes at all degrees. 10 x 20 cm-cylinder shaped concerete samples were prepared with the same method. Those samples were exposed to water cure and corrosive effects of H2SO4, MgSO4, NaCl from 28 to 120 days. There were made such experiments on those samples taken out of water cure and corrosive circumstances as visible gap rate, specific weight, water absorption rate, unit weight, tensile strength rate, capillary water absorption, impermeability, static elasticity module, pressure resistance, poisson rate and freez-thaw resistance.As a result, it was observed that, for all the specifications can be measured on concrete, antifreezes containing 30% of calcium nitrate and 5% of hydroxyethoxy amines and the concretes mixed with anti-freeze containing polyhydroxy amine give better results than the concretes mixed with the anti-freeze containing calcium nitrate. As another observation, it was also seen that anti-freezes containing calcium nitrate have the minimum and the antifreezes containing 30% of calcium nitrate and 5% of hydroxy ethoxy amine have the maximum performance. Besides at degrees below -5oC, performance of antifreeze admixture decreases.