Compressive Behavior of Concrete-Filled Filament-Wound FRP Tubes with Local Tube Damage

Abstract

Concrete-filled fiber-reinforced polymer (FRP) tubes (CFFTs) are an emerging and attractive form of column for new constructions. Such a column consists of outer filament-wound FRP tubes that are filled with plain or steel-reinforced concrete. The fibers in the filament-wound FRP tube are predominantly in the hoop direction to confine the inner concrete, which leads to significantly enhanced strength and ductility in the confined concrete. Extensive studies have been conducted on the behavior of CFFTs that were subjected to various loading conditions, which confirmed the excellent performance of such members. As CFFTs become increasingly used in practice, there is a concern about the performance of CFFTs when the FRP tube is subjected to local damage that is caused by accidents, vandalism, or designed holes or cuts to accommodate connections with other structural components. Some studies have been carried out on the performance of CFFTs as flexural members with a locally damaged filament-wound FRP tube; however, the research on such CFFTs as columns remains limited. This paper presented the results of a comprehensive experimental program on the axial compressive behavior of CFFTs with a filament-wound FRP tube that was subjected to local tube damage. Two types of damage (i.e., holes and cuts) with different parameters were investigated. The test results showed that the compressive strength [i.e., peak stress (fcc′)] and the corresponding axial strain (ɛcc) of the damaged CFFTs were significantly reduced due to the local tube damage (e.g., fcc′ reduced from 12.2% to 64.8% and the corresponding ɛcc reduced from 35.2% to 77.2%). Finally, an existing model for FRP-confined concrete that considered the local FRP damage was evaluated which suggested the need for the recalibration of the model or the development of a new model for CFFTs with a locally damaged filament-wound FRP tube.