Optimization of Concrete Beams Reinforced with GFRP Bars

Document Type : Regular Article


Lecturer, Department of Civil Engineering, Collage of Engineering, University of Basrah, Basrah, Iraq


Members with GFRP bars exhibit different behavior from those with steel bars due to the brittle and low elastic modulus of the GFRP bars. However, there are limited studies considering the optimum design of reinforced concrete members with GFRP bars compared with extensive studies for reinforced concrete members with steel bars. This study highlighted the performance of reinforced concrete beams with GFRP bars considering the optimum design. The behavioral flexural resistances involving compression, tension, and combined controls are incorporated in the formulation of the design constraints. Also, constraints including deflection serviceability limit states as well as construction requirements are considered. The optimization process is conducted using a genetic algorithm. Comparison with a conventional design is conducted by considering simply supported GFRP reinforced concrete beams in which the efficiency of the developed optimum design has been demonstrated. Analysis results show that tension-controlled sections govern the optimum design despite their brittle performance and highest reduction in strength. However, by increasing design restrictions including depth limits and deflection limits, tension-controlled sections became unable to provide sufficient strength and serviceability and the optimum design was shifted to a more ductile combined resisting control and then to compression-controlled sections.


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