Modeling of ultra-high performance fiber reinforced concrete columns under eccentric loading

Abstract

Recently, ultra-high performance fiber reinforced concrete (UHPFRC) has been widely used as a structural material. In this study, two finite element (FE) models are developed to investigate the behavior of UHPFRC columns under axial or eccentric loading. The analysis included two dimensional FE model using plane stress elements, and three dimensional FE model using solid elements. The FE models are verified using experimental results from the literature. It is proved that the FE models can predict the peak loads, modes of failure, and post-cracking behavior accurately. The FE interaction diagram agreed very well with the experimental results. The validated FE model is adopted to show the effectiveness of UHPFRC on the behavior of column versus using normal strength concrete (NSC) and high strength concrete (HSC). The FE results demonstrated that using UHPFRC improves the post peak ductility and increases the peak loads compared to those of NSC and HSC. Furthermore, a proposed simple analytical model is generated to predict the axial load-moment interaction diagram of UHPFRC columns and calibrated with both experimental and FE results. Comparing the analytical, experimental, and FE results showed that the proposed analytical model has comparatively high accuracy acceptable for practical design.