TY - JOUR
T1 - Compound concrete-filled FRP tubular columns under cyclic axial compression
AU - Zhou, J. K.
AU - Lin, Guan
AU - Teng, J. G.
N1 - Funding Information:
The authors are grateful for the financial support received from the Research Grants Council of the Hong Kong Special Administrative Region (Project Reference Numbers: PolyU 5252/13E and T22-502/18-R).
Publisher Copyright:
© 2021 Elsevier Ltd
PY - 2021/11/1
Y1 - 2021/11/1
N2 - The direct use of large pieces of crushed demolition concrete (referred to as recycled concrete lumps or RCLs) for mixing with fresh concrete to create a new kind of recycled concrete (referred to as compound concrete), has obvious advantages in terms of recycling efficiency, cost-effectiveness and maximum recycling ratio compared with the recycling of concrete as aggregates. Existing research has revealed certain performance concerns with such compound concrete, including reductions in strength and durability, due to the presence of RCLs. The confinement of compound concrete with an external fiber-reinforced polymer (FRP) confining tube has recently been explored as an effective technique to improve its mechanical properties and durability. This paper presents the results of the first ever experimental study on compound concrete filled FRP tubular (CCFFT) columns aimed at the understanding and modelling of the cyclic stress–strain behavior of FRP-confined compound concrete. The effects of RCL mix ratio, FRP tube thickness, and loading scheme are examined. A monotonic stress–strain model and two cyclic stress–strain models previously developed for FRP-confined normal concrete are used to predict the test results. It is shown that the inclusion of RCLs has a marginal effect on the cyclic stress–strain behavior of FRP-confined concrete.
AB - The direct use of large pieces of crushed demolition concrete (referred to as recycled concrete lumps or RCLs) for mixing with fresh concrete to create a new kind of recycled concrete (referred to as compound concrete), has obvious advantages in terms of recycling efficiency, cost-effectiveness and maximum recycling ratio compared with the recycling of concrete as aggregates. Existing research has revealed certain performance concerns with such compound concrete, including reductions in strength and durability, due to the presence of RCLs. The confinement of compound concrete with an external fiber-reinforced polymer (FRP) confining tube has recently been explored as an effective technique to improve its mechanical properties and durability. This paper presents the results of the first ever experimental study on compound concrete filled FRP tubular (CCFFT) columns aimed at the understanding and modelling of the cyclic stress–strain behavior of FRP-confined compound concrete. The effects of RCL mix ratio, FRP tube thickness, and loading scheme are examined. A monotonic stress–strain model and two cyclic stress–strain models previously developed for FRP-confined normal concrete are used to predict the test results. It is shown that the inclusion of RCLs has a marginal effect on the cyclic stress–strain behavior of FRP-confined concrete.
KW - Confinement
KW - Cyclic loading
KW - Fiber reinforced polymer (FRP)
KW - Filament-wound FRP tube
KW - Recycled concrete lump (RCL)
KW - Stress–strain behavior
UR - http://www.scopus.com/inward/record.url?scp=85112257580&partnerID=8YFLogxK
U2 - 10.1016/j.compstruct.2021.114329
DO - 10.1016/j.compstruct.2021.114329
M3 - Journal article
AN - SCOPUS:85112257580
VL - 275
JO - Composite Structures
JF - Composite Structures
SN - 0263-8223
M1 - 114329
ER -