Experimental Study on Diagonally Loaded Steel Fibre Reinforced Cement Concrete Frames

Many failures of framed structures have been attributed to the failure of beam column joints during the past earth quakes. During the analysis process of reinforced concrete frames, the joints between beams and columns assumed as rigid in general. In practise much attention is not given and the joint is usually neglected for specific design with attention being restricted to the provisions of sufficient anchorage for longitudinal reinforcement in beams. This is quite acceptable when the frame is not subjected to seismic loads. When these structures are subjected to seismic loads the performance of beam column joints leads to failure. The poor design practice of beam column joint is compounded by the demand imposed due to the adjoining members in the event of mobilising their inelastic capacities to dissipate seismic energy. This may be achieved by enhancing the properties of fibre reinforced concrete at these joints. An attempt is made in this paper to study the beneficial influence of steel fibres in reinforced concrete frames subjected to diagonally applied ultimate loads. Concrete specimens with adequate reinforcement are prepared and corrugated steel fibres of aspect ratio 50, with 0%, 1%, 2%, 3 % and 4 % dosages are introduced at the beam column joints. Concrete used in this study are M20 grade and M25 grade for which the mix design is done by using IS method. Specimens are subjected to ultimate loads. Non destructive tests are also conducted before and after the failure of specimens. From the test result