Model and parameters of freeze-thaw action spectrum for the needs of structural life-cycle design

The model of freeze-thaw action spectrum should include the annual average number of freeze-thaw cycle and the occurrence probability distribution of freeze-thaw cycle at different frozen temperatures. Due to the structural life-cycle design requirements, the probability of freeze-thaw cycle in China were analyzed employing the temperature data of more than 130 meteorological stations from 1951 to 2010. The freeze-thaw action spectrum of Harbin was drawn through data fitting with the ( left ) half normal distribution, under the freeze-thaw cycle occurrence condition of daily maximum temperature higher than OX and the minimum temperature lower than -32°C. The weather data of Beijing, Hohhot, Yining and Zhengzhou were investigated as well to verify the applicability of the half-normal distribution. At last, the parameters of freeze-thaw action spectrum of the main regions of China were given, and an express of freeze-thaw damage prediction of concrete structures were also given. Results show that the half normal distribution is suitable to compile freeze-thaw action spectrum for most areas of China. The method proposed herein could describe the strength of freeze-thaw action clearly, and could provide model parameters directly for the need of prediction of structural life-cycle design.