TY - JOUR
T1 - Shear behavior of a novel cold-formed U-shaped steel and concrete composite beam
AU - Zhao, Yi
AU - Zhou, Xuhong
AU - Yang, Yuanlong
AU - Liu, Jiepeng
AU - Chen, Yohchia Frank
N1 - Funding Information:
The authors are grateful to the support provided by National Natural Science Foundation of China (Grant No. 51878098 ) and National Key Research and Development Program of China (Grant No. 2016YFC0701201 , 2017YFC0703805 ).
Publisher Copyright:
© 2019 Elsevier Ltd
PY - 2019/12/1
Y1 - 2019/12/1
N2 - This paper discusses the shear behavior of a novel cold-formed U-shaped steel and concrete composite beam (RCUCB) composed of a rebar (reinforcing bar) truss for stiffening the open steel U-section, inverted U-shaped rebars for enhancing the continuity at the interface between concrete web and flange, and longitudinal bottom reinforcement for controlling the slip between steel U-section and encased concrete. A series of shear experiments on eight specimens were conducted, considering steel ratio (ρs), beam depth (H), and the number of bottom shear studs (nd). Two typical shear failure modes, depending on the shear span ratio (λ), were observed: diagonal compression failure when λ = 1.0; and shear compression failure when λ = 1.5. The respective ductility factors are 2.5–4.0 and 9.0–9.7. This indicates that a transitional shear span ratio (λ0) lies between 1.0 and 1.5. It is also obvious that shear lag effect exists in the concrete slab as the longitudinal strain of the concrete slab is 50–200% larger than the edge strain. Excellent integral action is ensured by the rebar truss and U-shaped rebars, thus enabling the concrete flange, web, and steel U-section to resist shear forces together. The steel ratio (ρs) has an obvious positive effect on the shear stiffness and capacity. The height to thickness ratio of the steel web is suggested to be no larger than 100 to avoid a local buckling before the peak load. A calculation method for the shear capacity of RCUCBs is proposed, which considers the contributions from the steel web, concrete, and dowel action.
AB - This paper discusses the shear behavior of a novel cold-formed U-shaped steel and concrete composite beam (RCUCB) composed of a rebar (reinforcing bar) truss for stiffening the open steel U-section, inverted U-shaped rebars for enhancing the continuity at the interface between concrete web and flange, and longitudinal bottom reinforcement for controlling the slip between steel U-section and encased concrete. A series of shear experiments on eight specimens were conducted, considering steel ratio (ρs), beam depth (H), and the number of bottom shear studs (nd). Two typical shear failure modes, depending on the shear span ratio (λ), were observed: diagonal compression failure when λ = 1.0; and shear compression failure when λ = 1.5. The respective ductility factors are 2.5–4.0 and 9.0–9.7. This indicates that a transitional shear span ratio (λ0) lies between 1.0 and 1.5. It is also obvious that shear lag effect exists in the concrete slab as the longitudinal strain of the concrete slab is 50–200% larger than the edge strain. Excellent integral action is ensured by the rebar truss and U-shaped rebars, thus enabling the concrete flange, web, and steel U-section to resist shear forces together. The steel ratio (ρs) has an obvious positive effect on the shear stiffness and capacity. The height to thickness ratio of the steel web is suggested to be no larger than 100 to avoid a local buckling before the peak load. A calculation method for the shear capacity of RCUCBs is proposed, which considers the contributions from the steel web, concrete, and dowel action.
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U2 - 10.1016/j.engstruct.2019.109745
DO - 10.1016/j.engstruct.2019.109745
M3 - Article
AN - SCOPUS:85073172002
SN - 0141-0296
VL - 200
JO - Structural Engineering Review
JF - Structural Engineering Review
M1 - 109745
ER -