Research of RC columns strengthened by carbon FRP under loading

The usage of carbon fiber-reinforced polymers (FRP) are described as modern methods of strengthening for reinforced concrete constructions. The advantage of these materials are the great corrosion resistance to environmental factors, high stiffness and strength and weight in comparison with other materials. The disadvantage of relatively high cost is offset by the cost reduction and labor when performing work on strengthening, by decreasing of performance time, by lack of needs to use the expensive equipment, installed and used without unloading the structures. This paper presents experimental results of 6 reinforce concrete columns strengthened by CFRP strips Sika Carbodur S512 with 50 mm width. The comparative analysis was carried out and strengthened effectiveness was determined for 2 unstrengthen control specimens, 2 specimens strengthened without initial load and 2 specimens strengthened at 1/2 of experimentally determined destructive efforts of the unstrengthen column.