• The International Concrete Abstracts Portal is an ACI led collaboration with leading technical organizations from within the international concrete industry and offers the most comprehensive collection of published concrete abstracts.

International Concrete Abstracts Portal


Title: Seismically Robust Ultra-High-Performance Fiber- Reinforced Concrete Columns

Author(s): S.-H. Chao, M. Shamshiri, X. Liu, G. Palacios, A. E. Schultz, and A. Nojavan

Publication: Structural Journal

Volume: 118

Issue: 2

Appears on pages(s): 17-32

Keywords: buckling; column; deformation capacity; earthquake loading; seismic; ultra-high-performance concrete (UHPC); ultra-high-performance fiber-reinforced concrete (UHP-FRC)

Date: 3/1/2021

Ultra-high-performance fiber-reinforced concrete (UHP-FRC) has a high compressive strength of 22 to 30 ksi (152 to 210 MPa) and a substantial shear strength as well as exceptional compressive ductility and confinement characteristics due to the addition of high-strength steel microfibers, which alleviate the need for excessive transverse reinforcement in high-strength concrete. The application of UHP-FRC in seismic-resistant reinforced concrete (RC) columns was investigated in this study. Two full-scale columns, one with normal strength concrete and the other with UHP-FRC in the plastic hinge region, were tested under simulated earthquake loads to evaluate their damage-resistance ability, deformation capacity, and failure mechanism. Experimental results show that the use of UHP-FRC changes the failure mode of RC columns as it improves confinement and shear capacity, as well as prevents concrete from crushing. The UHP-FRC column exhibits a higher peak strength and a greater deformation capacity before succumbing to significant strength degradation compared to the normal-strength RC column. The lateral displacements of the ACI 318-19-compliant RC column mainly result from distributed reinforcing bar yielding. Conversely, displacements of the UHP-FRC column are dominated by the slip deformation at the column-footing interface due to the strain penetration of the longitudinal reinforcing bars into the footing. Unlike the RC column, the failure of the UHP-FRC column is controlled by the low-cycle fatigue life of its longitudinal reinforcing bars. Concrete crushing in the RC column started at 1% drift ratio and became nearly unrepairable beyond 2.75% drift ratio. On the other hand, the UHP-FRC column experienced limited damage even at large drift ratios. This will result in great post-earthquake functionality and considerable cost savings in repairs for structures with UHP-FRC columns. In addition, incremental dynamic analyses of a four-story prototype RC moment frame indicate that buildings with UHP-FRC columns can sustain earthquakes with 20% higher peak ground acceleration before collapsing due to the greater deformation capacity.


Electronic Structural Journal


Please enter this 5 digit unlock code on the web page.