Conference Paper

Structural Behaviours of a Concrete Façade Panel Prototype Facilitated by 3D Printed Formwork

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Abstract

Façades are key building components, determining building performance and forming the interface between inhabitants and the general public. Accordingly, façades should integrate high aesthetic value with the capability to bear relevant loads. Contemporary architectural façade design strategies often employ complex shapes, which presents civil engineering challenges in terms of assessing structural performance as well as determining effective fabrication strategies. Using 3D concrete printing for fabrication can achieve freeform shapes but has several limitations including limited structural performance. Instead of directly 3D printing concrete elements, this paper presents an approach to fabricating geometrically complex façade elements in ultra-high-performance fibre-reinforced concrete using 3D printed formwork to achieve greater accuracy and cost efficiency compared to conventional fabrication methods. Following compression test and flexural test to examine the feasibility of using 3D printed formwork for concrete fabrication, a façade prototype with a non-standard shape using 3D printed polymer formwork and UHPFRC is examined for its structural behaviours. Results show that compressive strength and flexural strength are not affected negatively by the exterior 3D printed formwork. Meanwhile, the proposed façade prototype demonstrates good concrete flowability and load test results, promising a new construction method for concrete fabrication.

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World's First 3D Printed Bridge Opens in Spain, https://www.archdaily.com/804596/worldsfirst-3d-printed-bridge-opens-in-spain. Last Accessed 20 Mar 2022
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  • Ywd Tay
  • Gha Ting
  • Y Qian
  • B Panda
  • L He
  • M J Tan
Tay YWD, Ting GHA, Qian Y, Panda B, He L, Tan MJ (2019) Time gap effect on bond strength of 3D-printed concrete. Virtual Phys Prototyping 14(1):104-113
  • S Kim
  • T H Kang
  • K Hong
Kim S, Kang T. H.-K. and Hong S 2021 ACI Structural Journal 118 pp 167-77
World's First 3D Printed Bridge Opens in Spain ArchDaily
  • N Valencia
Valencia N 2017 World's First 3D Printed Bridge Opens in Spain ArchDaily
  • Asj Suiker
Suiker ASJ 2018 International Journal of Mechanical Sciences 137 pp 145-70
  • Y W D Tay
  • G H A Ting
  • Y Qian
  • B Panda
Tay Y.W.D, Ting G.H.A, Qian Y, Panda B, He L and Tan M.J 2019 Virtual and Physical Prototyping 14 pp 104-13
  • J G Sanjayan
  • B Nematollahi
Sanjayan J.G, Nematollahi B, Xia M and Marchment T 2018 Construction and Building Materials 172 pp 468-75
  • B Panda
  • Ywd Tay
  • Paul Sc
  • M J Tan
Panda B, Tay YWD, Paul SC and Tan MJ 2018 Material Science and Engineering Technology 49 pp 666-73
  • X Wang
  • M Jiang
  • Z Zhou
  • J Gou
  • D Hui
Wang X, Jiang M, Zhou Z, Gou J and Hui D 2017 Composites Part B 110 pp 442-58
TxA Emerging Design + Technology Conference (USA)
  • A Jipa
  • Bernhard M Dillenburger
Jipa A, Bernhard M and Dillenburger B 2018 TxA Emerging Design + Technology Conference (USA)