2018 Volume 72 Issue 1 Pages 240-246
Concrete deterioration due to scaling of surface became harder with increase of scattering deicer（NaCl）for concrete road structure. According to the previous researches which discussed about salt scaling, it is considered that the freeze and thaw process of the concrete surface affects the scaling. In order to elucidate the effect of the freezing and melting process of the deicer solution on the scaling, repeated tests of temperature drop and temperature rise were conducted in various temperature ranges from －40 to －3 degrees centigrade below the freezing point of the NaCl solution. The results obtained in this research that temperature range which scaling occurs is depended on the state of NaCl solution. In case of temperature drop and temperature rise of －20 to －10 degrees centigrade or passing through this temperature range during temperature drop and temperature rise, scaling occurs. In this temperature range, pure ice coexists with a high-concentration NaCl solution. In case of temperature drop and temperature rise in the range of －40 to －21 degrees centigrade which is a solid state of two components of pure ice and NaCl・2H2O, scaling does not occur. It is considered that scaling occurs due to the phenomenon that part of NaCl solution freezes and melts with temperature change.
