Theoretical and finite element analysis of HPFRCC columns in road and railways bridges under eccentric load

Reinforced concrete bridges are one of the most important structural elements in road and rail transportation systems. The use of cement-based alternative materials that have a better tensile behavior than concrete is always considered. The material of high performance fiber reinforced cementitious composite (HPFRCC) is of more resistance and ductility than normal concrete in tension, due to the strain hardening behavior under tension after formation of first cracking and bridges between the cracks by the fibers present in this material. In this study, the behavior of concrete and HPFRCC columns in bridges, that are under the eccentric load due to the dead load of the bridge deck, using finite element method with ABAQUS software, and theoretical method after validation with based on the experimental approach, have been compared. Also, in reinforced HPFRCC column, the effects of peak compressive stress, ultimate tension strain of HPFRCC and longitudinal reinforcement on variation of axial load-bending moment interaction curve have been investigated. The results show that the load carrying capacity of reinforced concrete and HPFRCC columns in the compression control area of axial load-bending load interaction curve is almost close to each other. But, the amount of balanced eccentricity and load carrying capacity of the HPFRCC column in the tension control area curve is higher than of the reinforced concrete column due to the change of the HPFRCC behavior in the tension compared to the concrete. The value of this increase in load carrying capacity varies and depends on the amount of eccentricity of axial load and is between 5.2% and 42.7%. Also, the amount of increase in balanced eccentricity is equal to 20%.