Compression behavior of ultra-high performance concrete (UHPC) confined with high-strength rectilinear ties

To explore the compression behavior of ultra-high-performance concrete (UHPC) confined with rectilinear ties, sixty specimens were tested under axial compression. The investigated parameters included the compressive strength of UHPC in the range of 84.72-155.45 MPa, the volumetric ratio of rectilinear ties in the range of 0.9-2.0%, and the yield strength of rectilinear ties in the range of 873-1215 MPa. The failure modes of specimens were the formation of an inclined shear failure plane. The axial stress-axial strain curves and the axial stress-lateral strain curves of confined UHPC were analyzed. Besides, the effects of investigated parameters on the load-bearing capacity and ductility of confined UHPC were analyzed. Moreover, the prediction models for the lateral strain of rectilinear ties at peak stress, load-capacity and ductility of confined UHPC were developed.