EXPERIMENTAL STUDY ON FROST AND FROST-DEICING SALT RESISTANCE OF CONCRETE

Frost resistance is one of important index of concrete durability, due to existing no unified index to reflect the durability of concrete perfectly, frost resistance is often used to evaluate the durability of concrete. In order to research frost and frost-deicing salt resistance of ordinary concrete and high strength concrete, and investigate the difference between frost and frost-deicing salt resistance of ordinary concrete and high strength concrete, the accelerated freeze-thaw tests in pure water and in 3.5% sodium chloride solution of ordinary concrete and high strength concrete have been carried out in laboratory, measuring weight, dynamic modulus of elasticity and compressive strength of specimens. The tests results show that, both the frost and the frost-deicing salt resistance of ordinary concrete and high strength concrete under no air-containing are very poor; The cycles number of frost and frost-deicing salt resistance of concrete increases with the increase in strength grade of concrete; The cycles number of frost resistance is higher than that of frost-deicing salt resistance for the ordinary concrete, while the cycles number of frost resistance is lower than that of frost-deicing salt resistance for the strength concrete; Only the weight loss rate and the relative dynamic modulus of elasticity as the judging criterion of frost and frost-deicing salt damage for concrete is not comprehensive enough, the strength loss rate should also be taken into account.