The research recognizes the necessity of developing a new method of calculation of pipe-concrete columns fire-resistance. It is important for expending the area of their application in construction of buildings and structures; in unique structures as well. The authors apply a simplified mathematical description of the process of pipe-concrete columns resistance to the standard fire effect. This method helps to increase the accuracy of fire resistance level determination to expand these constructions use. If buildings materials are rationally combined, it is possible to produce reliable and sufficiently fireproof structures. Pipe-concrete columns which are, in fact, metal pipes filled with concrete can serve as an example of such structures. Nowadays, field tests are used to determine pipe-concrete constructions fire resistance. The authors introduce a methodology of theoretical determination of pipe-concrete columns fire resistance limit. The use of the proposed methodology makes it possible to reduce labor and economic costs while determining buildings resistance with the use of the pipe-concrete. It opens a possibility of pipe-concrete structures reasonable application in construction practice. The use of this new method allows us to determine pipe-concrete columns fire resistance without resorting to natural fire. It also increases the accuracy of statistical quality control and non-destructive tests. The calculations made in this study as well as previous tests conducted by other researches prove that there is no need for additional fire protection of pipe-concrete columns.
Theory of Rolling for the Range of Mixed Friction : Part 1, A New Method of Calculation for the Rolling without Tension
