Experimental and analytical investigation for enhancement of flexural beams using multilayer wraps

摘要

Over the last two decades, fiber reinforced polymers (FRPs) have been widely accepted for rehabilitation and strengthening of reinforced concrete structures, as FRP externally bonded for enhancement of its strength and stiffness. This paper summarizes the results of experimental studies concerning the flexural strengthening of reinforced concrete beams by external bonding of single and multiple layers of lightweight fiber reinforced plastics (FRPs) wraps. Despite a substantial increase in the loading capacity and strength have achieved, reduction in ductility has also reported as a result of de-bonding failure at the FRP and concrete interface surface. The deterioration and loss of the mechanical properties of repaired flexural beams makes the loss of bond strength at the interface surface. For this reason the need for using multilayer of FRP wraps with U-shape vertical cross wrap configuration is most efficient in redistribution of the interface bond between reinforced concrete and FRP surface. Full scale eight flexural beams were tested to achieve the strength enhancement provided by FRP single and multilayer wraps. The tested beams with single and multilayer wraps are set up using different vertical U-anchor configurations. Analytical model was developed to compare the code limit with experimentally predicted results.