الفهرس 
1.2 Historical BackgroundOnly 14 pages are availabe for public view
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Abstract
Strengthening by fiber-reinforced polymer (FRP) systems for concrete structures are an alternative to traditional strengthening techniques. FRP strengthening systems use FRP composite materials as supplemental externally bonded reinforcement. In this research, an experimental program consists of eleven reinforced self-compact concrete beams was carried out to study the torsional behavior of concrete beams strengthened by FRP systems. One beam was considered as control beam and the other ten beams were strengthened with externally bonded Glass fiber-reinforced polymer (GFRP). The investigated variables in this study includes different wrap configurations such as: full and strip wrapping, the effect of the number of GFRP plies and the spacing between GFRP strips. Beams were tested till complete failure under pure torsion. Behavior of these reinforced concrete beams throughout the test was described using recorded data based on the measured values of the torsional moment at cracking and at ultimate, the corresponding twists, the behavioral curves and the failure modes. The test results confirm that the torsional behavior of tested beams strengthened by GFRP is better than the torsional behavior of the control beam. The experimental program includes also a new approach for producing a well-compacted concrete with good characteristic properties using self-compacting concrete. The main objective of using self-compacted concrete (SCC) is to resist segregation as it is compacted under own weight without any mechanical vibration.