Research on Ultimate Bearing Capacity of Reinforced Concrete Columns Subjected to Fire

According to Rankkine method, it finds a simple method to calculate the ultimate bearing capacity of reinforced concrete columns subjected to four-faced heating. This method is based on the study results by Dotreppe. And the concrete structure design Specification (GB50010-2002). Sixty-four columns from three different laboratories have been calculated by this method, and safe and correct results are got. An example using the simplified formulation has been presented. It can find that the method is simple and convenient, so it is fit for Chinese engineers.