Research On The Duration Of Fire Resistance Of Steel Reinforced Concrete Columns

Steel Reinforced Concrete (SRC) Structures are extensively utilized in multi-storey and high rised structures for their distinct economic and structural advantages, such as high load bearing capacity, excellent earthquake resistance qualities, and good anti-erosion properties. With the requirements of the fire resistance capability of structures being raised, the relevant capabilities of SRC structures are attracting more and more attention; however, few researches have been conducted so far globally. In this thesis, analysis will be undertaken on the factors of fire resistance capabilities of SRC columns, and subsequently the approach of calculating the duration of the fire resistance of SRC columns is generated for the engineering practice.By reviewing the relevant literatures and comparing the research results from several researches, thermal and mechanical properties of concrete and steel materials which will be applied to SRC columns at the high temperatures are selected. A general finite element analyzing software is utilized for establishing the 3D model of SRC columns, which is verified by experiments data herein. Parametric analysis on the duration of fire resistance of SRC column is taken in terms of uniform heating along the lengths of the column, square cross section, and heating process complied with ISO834 curves. Load ratio and section dimension are major factors which influence the duration of the fire resistance of SRC columns; and concrete strength, steel strength, slenderness ratio, eccentricity of columns, steel ratio, length-to-width ratio are minor factors. The thichness of concrete protecting layer around the steel section in current construction specifications can satisfy the pratical use for fire resistance requirements.