الفهرس 
NTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Reinforced concrete structures are vulnerable to high temperature conditions such as those during exposure to fire. At elevated temperatures, the mechanical properties of concrete and reinforcing steel as well as the bond between them may significantly deteriorate. The decrease in the bond strength may influence the moment capacity of the reinforced concrete elements. Assessment of bond strength degradation is required for structural design of fire safety and structural post-fire repair.
The main objectives of the current research are to assess the residual bond strength between concrete and steel rebars after fire exposure and to evaluate the effectiveness of using different repairing techniques and materials to restore the bond strength for post fire damaged concrete elements. To meet these objectives, experimental and analytical studies are carried out and documented in this Thesis.
The bond tests were carried out using beam end specimens. The test parameters considered in the current research include: exposure condition, concrete class, rebar type, rebar size, rebar location, repairing techniques and repairing materials. Two different exposure conditions were applied to the specimens. In the fire exposure condition, the specimens were subjected to a heating regime before testing in bond while in the ambient exposure condition, the specimens weren’t exposed to any heating regimes before testing. Two different repairing techniques were used in this study, namely deep repair and shallow repair. Four different repairing materials were also considered in the study namely; concrete (C), fiber reinforced concrete (FC), polymer modified cement mortar (M) and commercially available fiber reinforced polymer modified cement mortar (CM).
Based on the test results, simple analytical equations were developed to predict the bond strength for computation of the residual bond strength between concrete and steel rebars. A simple equation were developed to predict the bond strength for ambient condition and the residual bond strength for fire exposure condition. Analytical expression for the bond stress-slippage relationship have been proposed based on the Bertero-Popov-Eligehausen (BPE) relationship, to describe the bond slippage response for exposure conditions and different repairing techniques and materials. Correlation study between analytical and measured response of the tested specimens is conducted. Also, a heat transfer analysis was carried out using FEM to obtain the temperature distribution within the cross section of the fire exposed specimens.