Bond behaviour of steel-reinforcing bars in Crumb Rubber Concrete (CRC)

ABSTRACT

This paper assesses the bond-slip behaviour of Crumb Rubber Concrete (CRC) with embedded steel bars. A series of pull-out tests were conducted using CRC with 18% of the sand replaced by crumb rubber and traditional concrete (TC), with embedded steel bars of 12 mm and 16 mm in diameter. An ABAQUS model was developed to simulate the bond-slip relationship using cohesive elements and the model predictions agreed well with experimental results. The standardised bond strength of steel bars embedded in CRC is slightly lower than that of steel bars embedded in traditional concrete. The steel to concrete bond mechanism in CRC displayed similar behaviour to TC. Numerical results verified that the bond stress was uniform for short embedment bond specimens. A modified Eligehausen-Bertero-Popov model was able to satisfactorily predict the bond-slip relationship.

KEYWORDS:

• Bond behaviour
• pull-out test
• crumb rubber concrete
• reinforcing steel bar
• cohesive element method
• FEM (Finite Element Method)

Highlights

Crumb rubber from recycled tyres was used as a replacement of fine aggregate in concrete.

Pull-out tests were conducted to investigate the bond-slip relationship between CRC and steel bars.

An ABAQUS model was developed to simulate the bond-slip relationship using cohesive elements.

A modified Eligehausen-Bertero-Popov model was able to satisfactorily predict the bond-slip relationship of steel bars to CRC concrete.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Notes on contributors

Danda Li

Dr. Danda Li graduated from University of South Australia with a PhD in structural engineering in 2017. After graduation, Danda worked as structural engineer in industry for some time and also as researcher and tutor in UniSA. Her research interests include sustainable concrete materials and their structural applications.

Rebecca Gravina

Dr Rebecca Gravina is a Civil/Structural Engineer with 20 years experience in academia and consulting engineering. Her current position is as Associate Professor in Civil Engineering at RMIT University, Melbourne Australia and prior to joining RMIT she worked for ARUP consulting engineers in Melbourne as a structural engineer. A/Prof Gravina researcher expertise is in structural materials and analysis including non-linear finite element analysis of concrete structures, time-dependent behaviour, ductility and bond mechanics, repair and rehabilitation of deteriorated structures, fibre reinforced polymer (FRP) composites in construction, recycled materials, and engineering education.

Yan Zhuge

Dr Yan Zhuge is a Professor in Structural Engineering at School of Natural & Built Environments, University of South Australia, Australia. Yan has lectured in several Australian universities for more than 20 years. She has a BEng (Hons) in Civil Engineering and a Masters in Structural Engineering from Beijing, China, a PhD in Structural Engineering from Queensland University of Technology (QUT), Australia. Prof Zhuge’s main research interests include green concrete materials, composite materials and structures and seismic retrofitting of structures. She has published more than 160 SCI technical papers in the referred international journals and conferences and has been invited as a keynote speaker at several international conferences.

Julie E. Mills

Professor Julie E. Mills is Pro-Vice Chancellor of the Division of IT, Engineering and the Environment at the University of South Australia. Prior to joining the university Julie worked as a Structural Engineer for 15 years on projects ranging from power stations to houses. Julie’s diverse research interests include engineering education, gender studies and structural engineering and she has received national competitive grants and has numerous publications in all of these areas. Her current research in structural engineering is focussed on the use of recycled materials as partial aggregate replacement in concrete, particularly the use of crumbed rubber from used tyres as partial replacement for natural sands and the potential application of this rubberised concrete in residential construction.