Comparison Between Steel and FRP Reinforcement in Rectangular Concrete Columns Based on P-M Interaction Diagrams

Fiber Reinforced Polymer (FRP) materials are competitive option for replacing steel as structural materials, due to their durability in marine environmental conditions and reduced maintenance costs. These materials are available in different shapes, including I-section, bars and other structural sections. In this paper, steel and FRP reinforced concrete columns analyzed based on stress, strain and force diagrams for three available types of FRP including AFRP, CFRP and GFRP using Rectangular Stress Block (RSB) method in MATLAB, and the axial load-bending moment interaction diagram for each type of reinforcement was obtained. Finally, the behavior of columns was compared according to these P-M interaction diagrams. This comparison showed that columns reinforced with FRP bars, specially CFRP, exhibit an relatively increase in compressive axial capacity, but a reduction in bending capacity of columns. It can be concluded that FRP bars are good options as reinforcement for cases in which compressive axial capacity needs to be improved

Keywords:

Reinforced Concrete , FRP reinforcement , Columns , Load-Moment Interaction Diagram , Rectangular Stress Block Method