الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
It has become fibre-reinforced polymer (FRP) material alternative operable in order to replace steel rebar reinforcement in concrete structures to overcome steel rebar corrosion problems. However, one of shortcomings of glass fibres (GFRP) is its low elastic modulus. The main objective of this study using the concept of material hybridization is to develop a practicable hybrid FRP bar for concrete structures, especially for marine and port concrete structures. The purposes of hybridization are to increase the elastic modulus of GFRP bar with acceptable tensile strength and improve its flexural ductility. Two types of hybrid GFRP bar are considered in the development: GFRP crust with steel core bar and GFRP bar with steel wires dispersed over the cross-section. The results of this study indicated that the elastic modulus of the hybrid GFRP bar is increased by up to 379 percent by the material hybridization. The bars are locally produced by double parts die mold using local resources raw materials. A total of eight slabs, measuring 800 mm wide x 150 mm thickness x 2400 mm long, they are simply supported and tested in the laboratory under static four-line loading conditions to investigate their flexural limit states, including pre-cracking behavior, cracking pattern and width, deflections, ultimate capacities and strains, and mode of failure. The main parameters are reinforcement material type (GFRP, steel and HFRP bars). The ultimate load increased by 17.5 % as the reinforcement type (HFRP-C) compared with GFRP bars and produce some amount of ductility provided by the concrete. The recorded strain of HFRP (type C) reinforcement reached to 85% of the ultimate strains.
A nonlinear finite element model to investigate the flexure behavior of concrete slabs reinforced with hybrid HFRP reinforcement bars. The study is conducted using the nonlinear finite element program ‘‘ANSYS 19”. Nonlinear material models for the components of the concrete slab are used in the three dimensional finite element models. The outcomes obtained from the finite element analysis are correlated with experimental results. A broad parametric study is conducted to explore the effect of replacing steel reinforcement by different types of HFRP bars. The study showed that the contribution of hybrid rebars HFRP in concrete slabs improved slabs ductility and eliminated the unfavourable brittle failure of the concrete member. The design recommendations and guidelines are presented based on the results of both the experimental data and the non-linear FE.