الفهرس 
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Abstract
The thesis aimed to investigate the bond characteristics between R.C concrete beams and carbon fiber reinforced polymers, CFRP. The main objective of this research was to investigate the bond characteristics of R.C concrete beams strengthened with externally bonded CFRP strips in terms of the flexure capacity, the corresponding deflection, steel strains, CFRP strains, and modes of failure. The research program consisted of experimental and analytical studies.
Based on the results of the experimental program and adopted analytical models, design recommendations were introduced to predict the intermediate crack debonding failure strain.
The experimental program consisted of testing six beams, divided into three groups depending on different parameters. The first group consisted of three beams varying in bond length (specimens B2, B4 and B5). The second group consisted of three beams varying in concrete cover thickness (specimens B6, B8 and B3). The third group consisted of two beams varying in type of loading (specimens B2 and B6) to investigate the effect of the loading pattern on the debonding strain. The overall dimensions of the beams were 150 mm width, 300 mm depth and 3000 mm length. The clear span of the specimens was equal to 2800 mm. The beams were tested under increased static loading up to failure, using load control.
The analytical phase of this study included a rational analysis to predict the behavior of RC beams strengthened with CFRP strips at the tension side of the beam. An assessment regarding some of the existing codes provisions and models from the literature to predict intermediate crack debonding was performed for the results of experimental and for data available in the literature.
Based on the experimental results of the tested beams, literature data and the analytical work, a new factor was proposed to be added to some of the existing code provisions to predict the intermediate crack debonding failure strain tacking the bond length ratio (Ld/L) in to consideration. Several recommendations and design guidelines of RC beams strengthened by CFRP strips are introduced and presented.