Effect of Inorganic Salts on Frost Resistance of Concrete

摘要

Effects of water-binder ratio and inorganic salt additive，including NaCl, NaNO_2and Na_2SO_4, on frost resistance of concrete were investigated using the orthogonalexperimental test. There were two criteria, i.e., the relative dynamic elastic modulus(RDEM) and weight loss that can be used to evaluate the resistance of concretesubjected to fast freeze-thaw tests. The results show that the effect of water-binderratio on frost resistance of concrete is obvious and that the salts have different effects:adding NaCl and Na_2SO_4 into concrete decreases frost resistance and that the worsteffect occurs when the dosage of NaCl and Na_2SO_4 is about 0.5% and 1.25% ofcement, respectively. Adding NaNO_2 into concrete improves frost resistance but theeffect is not obvious. The influential effects of these salts are ranked to beNaCl>Na_2SO_4>NaNO_2.