Flexural and shear tests of ultra-high-strength reinforced concrete columns with fire protection after fire heating: Part 1 study on seismic performance of ultra-high-strength reinforced concrete columns after fire heating

This paper presents results of flexural and shear tests in order to examine the effect of fire heating on the seismic performance of reinforced concrete columns using concrete with a compressive strength of more than 100N/mm 2. Several fire protection measures were applied to these reinforced concrete columns before being exposed to fire for three hours. The following conclusions were obtained from (hose tests. 1) As the columns were exposed to higher temperatures, so the strength remaining after fire heating decreased. With the fire protection measures used in this study stiffness reduces to 60%-90% of initial values, while strength reduces to 60%-80%. 2) In addition, as heated temperatures increased, the failure modes shifted from the bending failure to shear failure. 3) A formula was developed which could indicate the tendency of the decrease in strength decline after exposure of the reinforced concrete columns to fire depending on heated temperature in the reach of this experiment.