Frost Resistance Of Concrete Subjected To Aircraft Deicer And Airfield Pavement Deicer

There are a wide range of deicing fluids that used for concrete pavement. For instance, the aluminum salts and urea are frequently used in municipal and expressway projects. In many airport projects, the organic alcohols aircraft deicer and acetate airfield pavement deicer are often used. In order to explore the relationships of concrete freezing-thawing resistance in different dicers, accelerated freezing-thawing experiments are carried out.In these experiments, the different freezing-thawing media include 3.5% Na Cl, 3.5% potassium acetate, 3.5% sodium acetate and 3.5% propylene glycol. In the mean time, experimental data of concrete exposed to 3.5%, 12.5%, 25% calcium magnesium acetate and ethylene glycol, which have been obtained in previous studies, are also employed to study the freezing-thawing resistance of concrete exposed to different freezing-thawing medias. Three series of concrete, which include thirteen proportions, are investigated. The three series are ordinary Portland cement concrete, silicate cement concrete and sulfate resistant cement concrete. Before freezing-thawing he specimens are cured at standard conditions for sufficient time. Failure mechanisms of rapid thaw cycles, the cement kinds, fly ash dosage, fiber hybrid and the different species and concentrations of deicing fluid are analyzed. The conclusions are as follows:(1) For concrete exposed to Na Cl, surface spalling is evident and is the main reason which account for the decreased freezing-thawing cycles. Excessive levels of FA is adverse to the freeze-thaw durability of concrete, the recommended dosage is between 20% and 30%.(2) As for HPC-P·? specimens exposed to 3.5% Na Ac solution, freezing-thawing resistance of concrete mixed with Modified Polyester Fiber(MPF) is decreased, while that of concrete mixed with Polypropylene Fiber(PF) is increased. Additionally, freezing-thawing resistance of concrete mixed with both MPF and PF is also decreased.(3) As for HPC-P·HSR specimens exposed to 3.5% Na Cl solution, freezing-thawing resistance of concrete with Modified Polyester Fiber is reduced, while that of concrete mixed with Polypropylene Fiber s increased exposed to 3.5% Na Cl and PG. The freezing resistance of concrete mixed with hybrid fiber is reduced exposed to Na Cl?PG and KAc. But if the hybrid fiber is SFR+PF, the freezing resistance of concrete is increased.(4) It is recommended to use CMA or 25% EG to remove ice and snow; Sulfate resistant cement concrete frost resistance is better than that of silicate cement concrete. The mixture ratio design of HPC-P·HSR1or HPC-P·HSR3 are suitable for Airport pavement.(5) Result shows that the freeze thaw cycle time of concrete in organic alcohols aircraft deicer(AD) and acetate airfield pavement deicer(APD) have a linear correlation with that in water.(6) The higher the deicing fluid concentration was, the freezing point depression effect was. In addition, the effect is related to the kind of deicing fluid.(7) When exposed to 3.5% deicing fluid, the sequence of the concrete freeze thaw cycle times in descending order is: NCMA, NPG, NW, NEG, NNa Cl, NKAc, NNa Ac.