NUMERICAL SIMULATION OF BEAMS MANUFACTURED WITH ULTRA- HIGH PERFORMANCE FIBER REINFORCED CONCRETE (UHPFRC)

Resumo

The ultra-high performance fiber reinforced concrete (UHPFRC) is a new material that
exhibits strength values higher than 150 MPa and 18 MPa in compression and tension, respectively. Its
dense matrix minimizes pores and increases durability. The presence of fibers, increases the energy
absorption capacity, induces deformation hardening behavior in the post-cracking phase and prevents
fragile failure, when subjected to stress tensions. These properties place the UHPFRC among the most
advanced concrete technologies, enhancing their use in the construction or repair of bridges, high-rise
buildings and special structures such as nuclear facilities. The objective of this work is to numerically
model the behavior of beams subjected to bending stress, through a finite element analysis using
ANSYS. A total of thirteen beams were tested experimentally; these results are compared with the
numerical simulation. Steel fibers with an aspect ratio of 65 were used, in percentages of 1% and 2%.
In the simulation, 150.89 MPa is considered as the average value for the compressive strength,
obtained from experimental tests carried out on twenty specimens. The elastic modulus considered is
obtained from the behavior curve, by linear approximation between 5% and 80% of the peak
resistance, whose average value was 48 GPa. Additionally, fracture energy is measured, which
reached values of 16,26 kJ / m2 and 22,60 kJ / m2 for fiber percentages of 1% and 2% respectively.