TY - JOUR
T1 - Behavior of Different-Sized FRP-Confined Square Compound Concrete Columns Containing Recycled Concrete Lumps
AU - Chen, G. M.
AU - Zhang, J. J.
AU - Lin, Guan
AU - Wu, Y. F.
AU - Jiang, T.
N1 - Funding Information:
The authors are grateful for the financial support received from the National Natural Science Foundation of China (Project Nos.: 51678161 and 51978281), Guangdong Provincial Key Laboratory of Modern Civil Engineering Technology (Project No.: 2021B1212040003), and the Research Grants Council of the Hong Kong Special Administrative Region (Project No: T22-502/18-R).
Publisher Copyright:
© 2022 American Society of Civil Engineers.
PY - 2022/4/1
Y1 - 2022/4/1
N2 - A new concrete recycling method is to crush demolished concrete into distinctly large recycled concrete lumps (RCLs), which are in a direct mix with fresh concrete, leading to the so-called compound concrete. Not only can this method decrease the recycling cost by simplifying the recycling process, it can also increase the recycling ratio. However, existing studies have demonstrated that such compound concrete is inferior to normal concrete. To improve the performance of compound concrete, an effective technique is to confine the compound concrete using fiber-reinforced polymer (FRP)-confining tubes, as demonstrated by a limited number of studies through tests on circular compound concrete columns. However, no studies have been done on FRP-confined rectangular compound concrete columns. Moreover, the possible column size effect in such columns has never been investigated; indeed, existing studies have revealed that FRP-confined rectangular normal concrete columns of different-sized specimens may exhibit obvious behavioral difference. Against this background, this paper presents the results of the first-ever experimental program on glass FRP (GFRP)-confined square compound concrete columns of three different sizes. The columns of different sizes had the same effective FRP confinement stiffness, and, therefore, the possible column size effect could be revealed. It was observed that the column size effect was obvious in the test columns in terms of compressive strength. Finally, three existing compressive strength models originally developed for FRP-confined normal concrete were evaluated using the present test results.
AB - A new concrete recycling method is to crush demolished concrete into distinctly large recycled concrete lumps (RCLs), which are in a direct mix with fresh concrete, leading to the so-called compound concrete. Not only can this method decrease the recycling cost by simplifying the recycling process, it can also increase the recycling ratio. However, existing studies have demonstrated that such compound concrete is inferior to normal concrete. To improve the performance of compound concrete, an effective technique is to confine the compound concrete using fiber-reinforced polymer (FRP)-confining tubes, as demonstrated by a limited number of studies through tests on circular compound concrete columns. However, no studies have been done on FRP-confined rectangular compound concrete columns. Moreover, the possible column size effect in such columns has never been investigated; indeed, existing studies have revealed that FRP-confined rectangular normal concrete columns of different-sized specimens may exhibit obvious behavioral difference. Against this background, this paper presents the results of the first-ever experimental program on glass FRP (GFRP)-confined square compound concrete columns of three different sizes. The columns of different sizes had the same effective FRP confinement stiffness, and, therefore, the possible column size effect could be revealed. It was observed that the column size effect was obvious in the test columns in terms of compressive strength. Finally, three existing compressive strength models originally developed for FRP-confined normal concrete were evaluated using the present test results.
KW - Fiber-reinforced polymer (FRP)
KW - FRP tubes
KW - Recycled concrete lumps (RCLs)
KW - Size effect
KW - Square columns
KW - Stress-strain behavior
UR - http://www.scopus.com/inward/record.url?scp=85123942076&partnerID=8YFLogxK
U2 - 10.1061/(ASCE)CC.1943-5614.0001192
DO - 10.1061/(ASCE)CC.1943-5614.0001192
M3 - Journal article
AN - SCOPUS:85123942076
SN - 1090-0268
VL - 26
JO - Journal of Composites for Construction
JF - Journal of Composites for Construction
IS - 2
M1 - 04022003
ER -