3D non-linear finite element analysis of concentrically loaded high strength reinforced concrete column with GFRP bar

Abstract

The use of High Strength Concrete (HSC) material in Reinforced Concrete (RC) column has become widely used. HSC was found to be durable, strong in compression, but it has low ductility. This low ductility of HSC can be improved by providing confinement. However, for HSC with concrete strength higher than 70 MPa, additional clause for confinement in ACI 318-19 generates denser arrangement of transverse bars and eventually creates weak planes between the concrete core and the cover. These weak planes can trigger early cover spalling. To reduce the utilization of confining bars, high-strength Glass Fiber Reinforce Polymer (GFRP) bar can be used. However, the performance of GFRP bar varies significantly from their uniaxial behavior in tension or compression to the real performance when it is used as the main reinforcement. For that reason, this paper tries to investigate the behavior of HSC RC column with bars made of conventional steel rebar and with GFRP bars. Due to limited data on the strain gauge reading on the GFRP bars from the available test result, an inverse analysis is carried out to determine the best stress-strain curve for GFRP bars used as the main reinforcement. For that purpose, an inhouse finite element package called 3D-NLFEA is used. From the comparisons, it was found out that the peak load, softening behavior, and the concrete core enhancement prediction agrees well with the test result. From the inverse analysis, only 25% and 45% of the GFRP bar yield strength can be deployed when loaded under compression and tension, respectively.

Numerical Investigation of Reinforced Concrete Beam Due to Shear Failure

“…The concrete constitutive model in 3D-NLFEA is similar to that of the plasticity-fracture model in the ATENA software package [5,15] . One can also find some examples of using the 3D-NLFEA finite element package in modeling RC structures in Christianto et al [16] , Prasetyo et al [17] , Alius et al [18] .…”

Structural Performance of Reinforced Concrete Columns with Bracing Reinforcement

“…Prasetyo et al [18] presented a numerical exploration on the attitude of RC column of steel and glass fiber reinforced polymer (GFRP) bars in high strength concrete stage. Since the uniaxial attitude of the GFRP bar changes considerably from compression to tension as it is employed as the main reinforcement, the outcomes revealed that only 25% under compression and 45% under the tension of the yield value of the GFRP bar can be employed.…”