Strengthening efficiency of RC beams strengthened with prestressed CFRP laminates

摘要

The paper concerns experimental tests on reinforced concrete (RC) beams strengthened with prestressed carbon fiber reinforced polymer (CFRP) laminates. The beams were exhausted to 14%, 25% or 76% of load capacity of non-strengthened beam before strengthening. Strengthening ratio varied in the range from 1,6 to 2,2 of the non-strengthened beam. Research showed high efficiency of strengthening with prestressed strips. Flexural strengthening with prestressed CFRP strips is very effective both for the ultimate and serviceability limit state, especially in case of highly preloaded elements. The active strengthening system causes significant reduction of strains in concrete, mid-span deflections and the increase in stiffness of the tested elements.