Three-dimensional-printed engineered, strain-hardening geopolymer composite as permanent formwork for construction of reinforced concrete beam

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Shin Hau Bong - , National University of Singapore (Author)
  • Behzad Nematollahi - , University of Sheffield (Author)
  • Viktor Mechtcherine - , Chair of Construction Materials (Author)
  • Victor C. Li - , University of Michigan, Ann Arbor (Author)
  • Kamal H. Khayat - , Missouri University of Science and Technology (Author)

Abstract

Extrusion-based concrete printing technology allows the fabrication of permanent formwork with intricate shapes, into which fresh concrete is cast to build structural members with complex geometries. This significantly enhances the geometric freedom of concrete structures without the use of expensive temporary formwork. In addition, with proper material choice for the permanent formwork, the load-bearing capacity and durability of the resulting structure can be improved. This paper investigates the concrete printing of permanent formwork for reinforced concrete (RC) beam construction. A three-dimensional (3-D)-printable engineered geopolymer composite or strain-hardening geopolymer composite (3DP-EGC or 3DP-SHGC), recently developed by the authors, was used to fabricate the permanent formwork. The 3DP-EGC exhibits strain-hardening behavior under direct tension. Two different printing patterns were used for the soffit of the permanent formwork to investigate the effect of this parameter on the flexural performance of RC beams. A conventionally mold-cast RC beam was also prepared as the control beam for comparison purposes. The results showed that the RC beams constructed using the 3DP-EGC permanent formwork exhibited superior flexural performance to the control beam. Such beams yielded significantly higher cracking load (up to 43%), deflection at ultimate load (up to 60%), ductility index (50%), and absorbed energy (up to 107%) than those of the control beam. The ultimate load was comparable with or slightly higher than that of the control beam. Furthermore, the printing pattern at the soffit of the permanent formwork was found to significantly influence the flexural performance of the RC beams.

Details

Original languageEnglish
Pages (from-to)37-48
Number of pages12
JournalACI structural journal
Volume121
Issue number2
Publication statusPublished - Mar 2024
Peer-reviewedYes

Keywords

Research priority areas of TU Dresden

DFG Classification of Subject Areas according to Review Boards

Subject groups, research areas, subject areas according to Destatis

Keywords

  • engineered geopolymer composite (EGC), permanent formwork, reinforced concrete beam, strain hardening, three-dimensional (3-D) concrete printing