PULL-OUT STRENGTH OF AN EXPANSION STUD ANCHOR IN CARBON FIBER REINFORCED CONCRETE

Abstract

Carbon Fiber Reinforced Concrete (CFRC) is considered as an innovative structural material
because of its better performance characteristics when compared to conventional concrete. Its common
applications where expansion stud anchor connection is possible are in slabs on grade, wall panel, curtain
walls, and pre-cast elements. The design of this stud anchor in CFRC is of great interest to many structural
engineers, however, no model is available as basis for its design. To develop such model, this study
investigated the pull-out strength of an expansion stud anchor embedded in CFRC as influenced by fiber
volume content (Vf), fiber length (Lf), compressive strength and tensile strength. Three compression, three
tension, and five pull-out CFRC specimens each of different Vf (0.10%, 0.15%, 0.20%, 0.25%, 0.30%) and
different Lf (19 mm, 30 mm, 38 mm) were prepared, tested, analyzed, and compared to control concrete
specimens at design compressive strength of 21 MPa. Tests results show that pull-out strength of an
expansion stud anchor in CFRC is maximum at Vf = 0.10% and Lf = 38 mm. Among the parameters
considered, tensile strength is the most significant contributing factor that could influence the pull-out
strength of stud anchor in CFRC. This is further verified numerically by a FEM model with good agreement
to the observed tensile strength. Finally, a Response Surface Methodology (RSM) model is proposed to
predict the pull-out strength of an expansion stud anchor embedded in CFRC as influenced by the fiber
volume content, fiber length, compressive strength, and tensile strength.