No abstract

The mechanical properties of fire-damage reinforced concrete columns strengthened with bonded steel angles were studied. Nine specimens were tested, including three normal temperature controlled columns, six heated under ISO834 standard fire. After exposure to fire, three of the six were rehabilitated with the bonded steel angles. It was shown by test results that the destructive properties of reinforced concrete columns with bonded steel angles may change and the small eccentric compression specimens may become large eccentric compression due to the steel angles increased the amount of steel in the tension zone of the specimen. In this research, compared with these under normal temperature, the bearing capacity of specimens which were exposure to fire was only ranged from 0.25 to 0.37 times. But the bearing capacity of specimens rehabilitated by the bonded steel angles can increase to 2.86 to 4.04 times of the originals and it can reach to the level of that in normal temperature.

The mechanical properties of fire-damaged reinforced concrete columns rehabilitated by carbon fiber-reinforced polymer (CFRP) rods were studied. This study aims at the effectiveness of CFRP through the contrast test. Nine specimens were tested, including three normal temperature control specimens, and six specimens heated under ISO834 standard fire. After the specimens were exposed to fire, three of them were rehabilitated by CFRP. All specimens were loaded monotonically to failure in the same way. The results showed that the failure of reinforced concrete columns rehabilitated by CFRP was due to losing stabilization, whereas the others were material broken. Furthermore, because of the fire, the load-bearing capacity of specimens was all declined sharply compared with these at normal temperature. From this research, comparing with these normal temperature control specimens, the load-bearing capacity of specimens exposed to fire firstly was ranged from 0.25 to 0.37 times. But the ratio of the loading capacity of specimens rehabilitated by CFRP and normal temperature control ones was ranged from 0.54 to 0.67.