Fracture behaviours of sustainable multi-recycled aggregate concrete under combined compression-shear loading

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Bin Lei - , Nanchang University, University of Technology Sydney (Author)
  • Hongchen Yu - , Nanchang University (Author)
  • Yipu Guo - , University of Technology Sydney (Author)
  • Wenkui Dong - , Chair of Construction Materials (Author)
  • Rui Liang - , University of Technology Sydney (Author)
  • Xiaonan Wang - , University of Technology Sydney (Author)
  • Xuqun Lin - , University of Technology Sydney (Author)
  • Kejin Wang - , Iowa State University (Author)
  • Wengui Li - , University of Technology Sydney (Author)

Abstract

Multi-recycling of concrete waste presents a promising alternative for reutilization of construction and demolition wastes. This study aims to investigate the synthetic effects of normal stress ratio (σ/fc) and number of recycling cycles (n) on mechanical performance and damage evolution of 3 generations of multi-recycled aggregate concrete (Multi-RAC) under combined compression-shear loading. Both the σ/fc and n significantly affect the failure mode, mechanical strength, stress-displacement relation, and damage evolution characteristics of Multi-RAC. The shear strength increases with the increased σ/fc, but decreases with the increased n except for σ/fc= 0. When σ/fc increases from 0 to 0.8, the failure modes shift from typical shear failure mode to complex failure one with combined shear and axial collapse features. The incemental reductions of contact friction strength and aggregate interlock strength are the main contributors to the decrease of shear strength with increased n. However, with increased σ/fc, the contributor fraction of contact friction strength contributing to the degradation of shear strength is decreased, whereas the corresponding contributor fraction of aggregate interlock strength is increased. The proposed aggregate interlock model of multiple recycled coarse aggregate (Multi-RCA) unveils the mechanism for the incremental reduction of aggregate interlock strength with the increasing n. The distinctively reduced volume fraction of natural coarse aggregate (NCA) in Multi-RCA mainly contributes to the reduced aggregate interlock strength. The findings provide an insight into the mechanical behaviors and damage evolution of Multi-RAC and can promote its application as structural concrete.

Details

Original languageEnglish
Article number106382
JournalJournal of Building Engineering
Volume72
Publication statusPublished - 1 Aug 2023
Peer-reviewedYes

Keywords

Keywords

  • Compression-shear loading, Damage evolution, Mechanical properties, Multi-recycled aggregate concrete, Strength criterion