الفهرس 
CHAPTER (1) IntroductionOnly 14 pages are availabe for public view
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Abstract
This study aims to investigate the structural behavior of multi-cell (MC) beams reinforced with metallic and non-metallic materials as the main reinforcement under the influence of bending loads. The term ”multi-cell” describes sections with numerous longitudinal hollow cores divided by thin webs. Sixteen beams were cast, cured, and tested under two loading lines system until failure. Based on the type of reinforcement used, the beams were divided into eight groups where each group consisted of two similar beams for more accuracy in the results. Based on the type of reinforcement, seven types of reinforcement were used which were steel bars and expanded steel metal mesh as a metal reinforcement in addition to geogrid mesh, CFRP strips (carbon fiber reinforced polymer), CFRP (carbon fiber reinforced polymer) rebar, BFRP (basalt fiber reinforced polymer) rebar, and GFRP (glass fiber reinforced polymer) rebar as a non-metal reinforcement. The number of reinforcement bars or mesh layers for each type was selected to keep the reinforcement ratio constant. All beams have external dimensions of 200×300×1800 mm and the same reinforcement ratio of 0.4% with simple supporting conditions. Control beams with solid sections and without any longitudinal cells (holes), as for MC beams, they contain 4 rectangular cells with dimensions of 60×90 mm along the entire length of the beam. The performance of MC and RC control beams was explored in terms of crack load, load-deflection curves, energy absorption capacity, ductility index, ultimate load-to-weight ratio, and crack pattern to evaluate the efficiency of using these beam elements. According to the obtained results, the MC beams reinforced with steel bars and CFRP rebar were able to achieve 75% and 83.3% of the control beam capacity with a 40% reduction in their weight compared to the control beam. To gain a deeper understanding of the behavior of multi-cell beams under flexural loading, The three-dimensional FE model was created using the computer software ABAQUS/CAE to simulate the multi-cell beams with their longitudinal and transverse reinforcement with their different materials used in this study. The average percentage of the first crack loads of the tested beams between the experimental results and the numerical results was 5.0%, while the average percentage of the ultimate loads of the tested beams between the experimental results and the numerical results was 2.6%. In addition, the average percentage of the maximum deflection of the tested beams between the experimental results and the numerical results was 4.1%. Therefore, there is a good agreement between experimental and numerical results. When compared to the control beam (CB), specimens reinforced with CFRP rebar (MC-C) and GFRP rebar (MC-G) presented a proper ultimate load with a suitable cost.