Numerical and Analytical Study of Reinforced Concrete Beams with Ultra-High Performance Fiber Reinforced Concrete (UHPFRC)

Resumo

Ultra-High Fiber Reinforced Concrete (UHPFRC) has recently been used to retrofit structures,
presenting great mechanical behavior under flexural loads. This work used the data of a developed numerical study
to develop a numerical and analytical methodology to obtain the ultimate bending moment (Mu) of a reinforced
concrete (RC) beam retrofitted with UHPFRC subjected to monotonic load. The numerical model was developed
in the commercial program ATENA 3D, using the Finite Elements Method (FEM). The numerical analysis
considered the nonlinear material behavior to obtain closer values to the experimental test. The analytical
methodology was based on the previous equations developed by other authors, with the modification of the tensile
diagram of the UHPFRC. The results obtained from both methods presented good accuracy in the ultimate bending
moment compared to the experimental one. Regarding the case study, the analytical and numerical models showed
differences of 7.1% and 2.9%, respectively, and similarity in the load-displacement curve of the retrofit beam with
UHPFRC. This work demonstrated the ability of the ATENA program to simulate the structural behavior of RC
beams retrofitted with UHPFRC. Finally, it is possible to conclude that both methodologies could determine the
ultimate bending moment for beams strengthened with UHPFRC.