Image from Gramazio Kohler Research, ETH Zurich. Sourced at https://gramaziokohler.arch.ethz.ch/web/e/forschung/221.html
Image from Gramazio Kohler Research, ETH Zurich. Sourced at https://gramaziokohler.arch.ethz.ch/web/e/lehre/199.html
Image from Gramazio Kohler Research, ETH Zurich. Sourced at https://gramaziokohler.arch.ethz.ch/web/e/lehre/219.html

Mapletree Timber Installation

Sub-Category:
Practice
Category:
Realised
Index:
56
Start Date:
2016
End Date:
2018
Role:
PI Principal Investigator
Concept:
accentuated mass
Duration (weeks):
100
No of Designs or Design Iterations:
1
No of Collaborators:
3
No of Students:
5
External Website:
Award | Exhibition:

Thin Silhouette 

The bench was developed as an outdoor installation for Mapletree Development and is permanently installed at their Mapletree Business City in Singapore. The STRUCTURE reflects a process of linear array of timber planks that span over a distance of 3.0 metres. A parabolic curve fits inside the geometry to make sure that there is a continuous, internal thrust line for the distribution of forces. The shape allows users for different types of inhabitation, from conventional usage as a bench to leaning against or resting the head against its slanted supports when lying on the ground, to more playful appropriations such as running across.

Robotic Milling

96 reclaimed wood planks are used for the CONSTRUCTION of the bench. They are part of 5,000 recovered planks from VivoCity shopping mall in Singapore. After a selection process to ensure adequate quality, the timber planks were dried, planed and temporarily glued into five blocks by a local carpenter. Of these blocks, one has dimensions of 176 cm by 78 cm and four have dimensions of 80 cm by 86 cm. They were precisely milled into their three-dimensionally curved geometries by a discrete robotic arm in a one-step process for the smaller blocks (one sided milling process), and in a two-step process for the large part (two sided milling with registration and reference points). In all blocks, groves were carved into the surfaces for the placement of artificial fibres. The five blocks were eventually joined and assembled with traditional woodcraft techniques. For both the selection of the planks and the joinery, the collaboration with an old carpenter was crucial. The air drying went hand in hand with a visual assessment to determine the quality and was done by a craftsmen with 40 years of experience. The wood industries in Singapore are considered a sunset industries, which was pushed out of urban construction through the reliance on concrete and steel as primary materials, implications of modernism and industrialisation.

Fibre Winding

In the final step of the construction process, the bench was wrapped in carbon fibres in two directions: lateral fibres tie the planks together, comparable to the principle of  steel bands that take on the tension forces on wood barrels. Longitudinal fibres reinforce the wood and increase the structural capacity of the bench and turn it into a proof-of-concept study for the potential application of the concept as a load bearing beam in full-scale construction. The combination of reclaimed wood and high-performance carbon fibres turns the construction into a hybrid MATERIAL system. 

Fibre Pattern

The finished product displays two types of pattern: the natural fibre grain in the reclaimed wood planks that is partly enhanced through uneven weathering, and the artificially embedded traces of the carbon fibres. The geometric pattern becomes thus a display of the TECTONIC systems at play. The artificial fibres are reinforcing the natural fibre composites of the wood planks, partly correlating in their directionality, partly  tying the planks in lateral direction. The application of fibres distinguishes between compression and tension force lines and leads to a strategic placement of fibres where they are utilised most. Structural simulation software was used to assess the fibre placement (Karamba plugin in the Rhino / Grasshopper modelling environment) and  was further used to determine the geodesic lines on the surface geometry, which was important for curvilinear continuity and precision of the paths. The fibres further require that they are exclusively placed on convex parts of the geometry. The materially reduced and thin silhouette together with the fibres becomes reach an ‘almost perfect realization of a structural principle in terms of a most appropriate and efficient construction while, at the same time, a clearly related unequivocal tectonic expression is found’ (from Sekler, Eduard (1965) Structure, Construction, Tectonics).

Collaborators:
Kenneth Tracy, Sachin Gupta, Dhileep Jayashankar
Students:
Kerine Kua, Jean Lee, Melissa Lee, Jia Neng Seah, Daniel Yong
No items found.
Images (c) Gramazio Kohler Research, ETH Zurich
Images (c) Gramazio Kohler Research, ETH Zurich
Images (c) Gramazio Kohler Research, ETH Zurich
Publications:
Publications:
pdf file download:
eth-49664-01.pdf
Publications:
pdf file download:
eth-49662-01_compressed.pdf
Publications:
Part 1 download pdf: 
eth-49663-01_compressed_01.pdf
Part 2 download pdf: 
eth-49663-01_compressed_02.pdf
External Website:
Collaborators:
Kenneth Tracy, Sachin Gupta, Dhileep Jayashankar
Students:
Kerine Kua, Jean Lee, Melissa Lee, Jia Neng Seah, Daniel Yong