The transfer length in reinforced concrete structures strengthened with composite plates: Experimental study and modelling

The present work is an experimental investigation of the load transfer mechanism between substrate and reinforcement in various concrete specimens strengthened with composite plates. Compressive and tensile tests are carried out. Strain gauges bonded near the end of the composite provide the strain distribution and clearly show that a transfer zone takes place. These experimental results are then compared to the usual theoretical model for bonded joints. It is shown that the experimental transfer length is greater than its theoretical counterpart in all cases under study. A modified expression of this transfer length is eventually proposed to account for this observation. This expression is also validated by some finite element simulations presented in the paper.