Triaxial mechanical behaviours and life cycle assessment of sustainable multi-recycled aggregate concrete

Bin Lei; Linjie Yu; Yipu Guo; Hongjie Xue; Xiaonan Wang; Yan Zhang; Wenkui Dong; Frank Dehn; Wengui Li

doi:10.1016/j.scitotenv.2024.171381

Triaxial mechanical behaviours and life cycle assessment of sustainable multi-recycled aggregate concrete

Sci Total Environ. 2024 May 1:923:171381. doi: 10.1016/j.scitotenv.2024.171381. Epub 2024 Mar 3.

Authors

Bin Lei¹, Linjie Yu², Yipu Guo³, Hongjie Xue⁴, Xiaonan Wang⁵, Yan Zhang⁴, Wenkui Dong⁶, Frank Dehn⁷, Wengui Li⁸

Affiliations

¹ School of Infrastructure Engineering, Nanchang University, Nanchang 330031, China; Centre for Infrastructure Engineering and Safety, School of Civil and Environmental Engineering, The University of New South Wales, NSW 2052, Australia.
² School of Infrastructure Engineering, Nanchang University, Nanchang 330031, China.
³ Centre for Infrastructure Engineering and Safety, School of Civil and Environmental Engineering, The University of New South Wales, NSW 2052, Australia. Electronic address: yipu.guo-1@uts.edu.au.
⁴ College of Harbour, Coastal and Offshore Engineering, Hohai University, Nanjing 210098, China.
⁵ Centre for Infrastructure Engineering and Safety, School of Civil and Environmental Engineering, The University of New South Wales, NSW 2052, Australia; School of Civil and Environmental Engineering, University of Technology Sydney, NSW 2007, Australia.
⁶ Institute of Construction Materials, Technische Universität Dresden, 01062 Dresden, Germany.
⁷ Institute for Concrete Structures and Building Materials, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany.
⁸ Centre for Infrastructure Engineering and Safety, School of Civil and Environmental Engineering, The University of New South Wales, NSW 2052, Australia; Institute for Concrete Structures and Building Materials, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany. Electronic address: wengui.li@unsw.edu.au.

PMID: 38442756
DOI: 10.1016/j.scitotenv.2024.171381

Abstract

Multi-recycling of concrete waste presents a promising avenue for carbon-negative development and a circular economy. This study comprehensively assesses the triaxial mechanical performance and environmental impact of multi-recycled concrete (Multi-RAC) through three recycling cycles. The results reveal a triaxial failure mode similar to natural aggregate concrete (NAC). The peak stress and peak strain monotonically increase with confinement stress, showing a significant impact (enlarged by 171.4 % to 280.6 % and 397.4 % to 412.0 %, respectively) from 0 to 20 MPa. All P-values for recycling cycles and confining pressure are less than 0.05, with the confining pressure having a more significant effect. Three best-fit multivariate mixed models predict mechanical properties, and a modified elastoplastic model introduces the recycling cycles factor. Numerical simulations confirm the model's accuracy in predicting the triaxial mechanical properties of Multi-RAC. Comparative analysis reveals that the elastoplastic model-derived non-integral high order failure criterion outperforms the Willam-Warnke failure criterion and other conventional criteria. Regarding environmental impact, all indicators (GWP, POCP, AP, EP, and CED) decrease favourably with the increasing number of recycling cycles, with CED and EP playing the most significant roles. Compared to NAC, the five environmentally favorable indicators for RACIII decrease by 3.24 % to 50.6 %, respectively. These findings provide valuable insights for future research on developing eco-friendlier Multi-RAC for sustainable and green infrastructure.

Keywords: Elastoplastic model; Failure criteria; Life cycle assessment; Multi-recycled aggregate concrete; Triaxial behaviour.