Technical gazette, Vol. 29 No. 4, 2022.
Preliminary communication
https://doi.org/10.17559/TV-20210705101118
Strength Degradation Characteristics of the Steel-Concrete Interface Under Cyclic Shear
Mingwei Liu
; National Engineering Research Center for Inland Waterway Regulation, School of River and Ocean Engineering, Chongqing Jiaotong University, 66 Xuefu Road, Nan'an District, Chongqing 400074, P. R. China
Fayou Wu
orcid.org/0000-0002-0654-1647
; National Engineering Research Center for Inland Waterway Regulation, School of River and Ocean Engineering, Chongqing Jiaotong University, 66 Xuefu Road, Nan'an District, Chongqing 400074, P. R. China
Erdi Abi
; National Engineering Research Center for Inland Waterway Regulation, School of River and Ocean Engineering, Chongqing Jiaotong University, 66 Xuefu Road, Nan'an District, Chongqing 400074, P. R. China
Linjian Wu
; National Engineering Research Center for Inland Waterway Regulation, School of River and Ocean Engineering, Chongqing Jiaotong University, 66 Xuefu Road, Nan'an District, Chongqing 400074, P. R. China
Guangquan Su
; National Engineering Research Center for Inland Waterway Regulation, School of River and Ocean Engineering, Chongqing Jiaotong University, 66 Xuefu Road, Nan'an District, Chongqing 400074, P. R. China
Abstract
The shear capacity of the steel-concrete interface (SCI) of concrete-filled steel tubular piles (CFSTs) degrades due to the cyclic shear action of external loading and unloading and can result in a reduction in the bearing capacity. To explore the shear strength degradation characteristics of the steel-concrete interface under cyclic shear, cyclic shear tests for three roughness types and under four different normal stresses were carried out by using a large-scale repeated direct shear test system. The characteristics of the shear load-displacement curve and failure mode of the SCI under external cyclic shear were analyzed, and the influence of the roughness and normal stress on the SCI shear strength degradation was explored. The results indicate that the CFSTs experienced shear failure in the first three shear cycles and then exhibited wear failure. The peak shear load of the SCI increases exponentially with increasing normal stress and decreases logarithmically with increasing cyclic shear time. A larger interfacial roughness and normal stress results in a faster interfacial shear strength ratio (τfn/τf1) weakening during the first three shear cycles, and with an increase of the cyclic shear times, the weakening rate is reduced.
Keywords
degradation characteristics; failure mode; large-scale cycle shear test; roughness; steel-concrete interface
Hrčak ID:
279498
URI
Publication date:
17.6.2022.
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