Behavior of long circular SIFCON columns under eccentric loading

This work examines the effect of eccentric loading on the behavior of long, circular columns that are made of Slurry Infiltrated Fiber Concrete (SIFCON) and Normal Strength Concrete (NSC). Two sets of column specimens were cast and tested, namely SIFCON (experimental) and NSC (control). Every set consists of three columns with varying eccentricity values (e = 0 mm, 30 mm, and 60 mm). Hooked-end micro steel fibers were incorporated into the SIFCON mix at a volume fraction of 6 %. Compared to the NSC columns, the SIFCON specimens exhibited enhancements in ultimate load-carrying capacity, ultimate axial displacement (movement in the direction of the load), mid-height lateral displacement (movement perpendicular to the load), first crack load (load at which initial cracking occurs), secant stiffness, and initial stiffness. These improvements were observed across all eccentricity levels. However, for both SIFCON and NSC columns, increasing eccentricity led to reductions in load-carrying capacity, first crack load, secant stiffness and initial stiffness. On the other hand, ultimate axial and mid-height lateral displacements increased with eccentricity in both column types. The failure mode for concentrically loaded columns (e = 0 mm) was identified as compressive failure in both SIFCON and NSC, whereas for eccentrically loaded columns (e = 30 mm and 60 mm), the failure mode was tensile failure.