Anchorage strength of stainless steel T-bolt in square concrete-filled stainless steel tubes

Abstract

A stainless steel T-bolt was proposed to achieve one-side access joints for concrete-filled steel tubular structures. This paper presents an experimental and theoretical study on the anchorage behavior of a single stainless steel T-bolt embedded in square thin-walled concrete-filled stainless steel tubes (CFSSTs). Pullout test was conducted on a total of 47 specimens, including single-head T-bolt in CFSST, double-head T-bolt in CFSST, single-head T-bolt in square hollow tube (SHS), and single-head T-bolt in plain concrete. Failure modes, load-displacement curves, and anchorage strength were obtained from the experiments. Key parameters affecting anchorage strength were examined, including anchorage depth, tube thickness, concrete grade, anchor size, bolt position, and bolt type. Theoretical analysis was then conducted to identify the force transfer mechanisms in specimens and design formulas were proposed to predict the anchorage strength of T-bolts in CFSSTs. The predictions were in good agreement with the experimental results, demonstrating the reasonability of the proposed theoretical models.