The paper investigates the axial capacity of reinforced columns exposed to fire. The simplified method namely 500°C isotherm method explained in Eurocode 2 is used to assess the capacity of the column. Finite element software ANSYS is used to perform the thermal analysis. A set of numerical studies were carried out to quantify the effect of various parameters on short columns subjected to fire. The study is performed on columns of different cross-sections to investigate the effect of eight parameters, namely the thermal boundary conditions, grades of concrete, grades of steel, types of aggregate, distribution of reinforcement on column faces, concrete cover, load eccentricity and support conditions. The fire ratings based on various failure criteria are determined, and minimum rating is accepted as design fire rating. A simplified interaction curve to predict the failure of columns under fire subjected to axial load and uniaxial moment for square cross-sections was also developed

Generally structural members can be broadly divided into two regions, namely B or Bernoulli regions where the strain distributions are linear and D or Disturbed regions where the strain distributions are nonlinear. A beam whose depth is comparable to span is known as deep beam and these structural elements belong to D regions. It has been recently understood that the strut and tie method (STM) is an effective tool for the design of both B and D regions. The present code recommendations are inadequate for the design of deep beams. In this paper simple equations using STM are developed for finding the area of main steel required to have a balanced type of failure and to find the ultimate capacity of deep beams failing in different failure modes. These equations are compared with experimental results and a good agreement is found.