Strengthening Of R.C. Beams By External Steel Plate Using Mechanical Connection Technique

Abstract

The volume of the infrastructure that needs upgrading, strengthening and/or repair is growing worldwide. A strengthen method that was used quite extensively during the mid 1970s is steel Plate Bonding, this method has gained renaissance in the last decades. This paper presents experimental test data with theoretical analyses on the effect of replacing internal tension bars by externally steel plate on its cracking pattern, structural deformations and ultimate strength of concrete beams reinforced with external using mechanical connection technique. The traditional method use the epoxy glues for interfaces bonding while the idea of this new technique is connection the internal shear reinforcement with the external steel plate mechanically. The experimental work includes flexural testing of 100 150 1500mm concrete beams. The test variable included the percentage of replacing the internal reinforcement with external steel plate. Theoretical analyses implemented by ANSYS finite element program for all beams also presented. The results show that beams reinforced with external steel plate behave as a composite action right up to ultimate load and the mode of failure occurs by yielding of external plate not by separation of plate. Replacing the internal by external steel restrains the central deflection with considerable increasing of ultimate moment capacity. The ratio of steel replacement with 33%, 67% and 100% leads to deflection drop with 12.5%, 7.7% and 4.6% respectively. Results show good agreement between the experimental and theoretical output data.