Experimental and numerical investigations of the seismic performance of columns with fiber-reinforced concrete in theplastic hinge region

Abstract

Fiber-reinforced concrete materials have high tensile toughness and exhibit multiple micro-cracking behavior and strain-hardening property in direct tension loads. To improve the seismic performance and damage tolerance of reinforced concrete columns, nine columns using fiber-reinforced concrete in the lower 300-mm end region and one conventional reinforced concrete column were designed and tested under lateral cyclic loading. The test parameters included the axial load ratio and the shear span ratio. The cracking and failure modes, hysteretic behavior, deformation capacity, energy dissipation capacity, and stiffness degradation of all specimens were analyzed in detail. In addition, a finite element model was established, and a parametric analysis was conducted. The test results showed that the fiber-reinforced concrete columns with a shear span ratio of 2.0 experienced bending failure, and that the strength and stiffness degraded at a lower rate compared to the normal concrete counterpart. The axial load ratio and shear span ratio had a significant effect on the deformation capacity and energy dissipation capacity of the columns. Fiber-reinforced concrete columns with just shear-resisting stirrups can satisfy the deformation and energy dissipation requirements.