GIVING FIRST AID TO BRANCHINGS

15.06.2022

In today’s timber industry, the amount of waste is enormous – and practically only three types of wood are acceptable. Anders Kruse Aagaard carries out research into how new types of wood can be introduced into the building sector, and how we can make better use of the resources of wood.

Slices and squares. That’s roughly what our wood is turned into after a trip to the sawmill. For these shapes are suited to industrialised construction and the relevant regulatory standards.

However, Aarhus School of Architecture is home to researchers who imagine a better world. A world where the original shapes of the wood are reintroduced into the building sector – with the aid of high tech.

Thinking wood

One such researcher is Associate Professor Anders Kruse Aagaard. He spends most of his waking hours thinking about wood. Recently, an exhibition created by Anders and Associate Professor Niels Martin Larsen, called Thinking Wood, was on display at the school.

At the exhibition were pieces of wood with curved shapes that had passed through the two men’s rugged hands – as well as metallic claws of the robot. For it’s all based on the interaction between people and machines.

A computer is capable of managing huge amounts of data and can help us identify the pieces that are best suited for a specific purpose.

‘We have been cooperating with a sawmill, where the curved branchings and trunks were 3D scanned and entered into a database. Thus, in a manner of speaking, creating digital twins of each piece of wood. We next coded software that made it possible to draw a curved shapes in projects. The computer then checks the database to find the most suitable piece of wood. The result never entirely resembles what you drew – but is that even necessary? Anders asks rhetorically.

Being serious about the properties of wood

In modern house construction, the approach is different. Here you call the factory that makes glued laminated timber, they then glue some straight boards together to make a curved shape. You need to insert steel components into these elements, to keep them from unravelling. And you typically also assemble the beams using steel brackets. Instead, you could perhaps have used a piece of hard beech wood. Which can obtain the same rigidity as steel, Anders says.

‘If, in the future, we are going to be building many structures in wood, we will have to think about resources. The need will become so massive that we need a more nuanced approach to which type of wood we use – and we need to consider the properties of the material more carefully.’

Today, we, for instance, reject huge quantities of wood from the rainforests because it smells of ‘tree sweat’ for some time after it has been cut. The typical Danish family wouldn’t accept their new garden furniture smelling like that.

‘The new bridge behind Aarhus City Museum is actually built from jungle wood like that. And, no, it really doesn’t smell very good to begin with’, Anders admits.

Always cutting

Anders Kruse Aagaard’s love of wood is an old passion, but as we all know wood doesn’t rust. When he was a boy in Gug, near Aalborg, he was cutting sticks and doing carpentry and was generally up to his ears in wood shavings. He also often drew and did visual arts.

However, because he was good at scholarly subjects, his craft skills were regarded purely as a hobby project – by the grown-ups and by himself. In the 8th grade, he did an internship in the municipality’s architectural office. And this was where his dreams about the subject began to take shape.

After high school, he performed his military service and worked odd jobs. Among other things, he worked in a label printing company. His fondness for large machines would seem to be a recurring theme. And today, 22 years later, he spends much of his time milling or operating one of the school’s other large machines in the well-equipped workshop facilities.

You need to understand both the machine and the material

He has helped choose many of the machines the school purchased. It therefore made sense for him to apply when a PhD position based on the new machine park was advertised. His PhD dissertation, Bespoke Fragments, had a digital slant and dealt with three materials: wood, steel and concrete.

‘There was a good deal of existing research into how you use digital tools to produce specific shapes. I turned it upside down, wanting to understand the machine and the material – and then see what would come of this.’

This exploration developed into an iterative process: he tested things, examined the results, made adjustments, and tried again. This is also his approach to the research he is doing today.

‘When you draw in the materials themselves, you don’t so much draw finished pictures. You draw a line that informs the next line. The material is perhaps then split, and this then informs your next choices. You build drawings or geometries. Recipes, workflows and procedures. In this way, you link the architect’s drawings with the machine and the material’, Anders explains.

Wood – the unpredictable material

In the process you perpetually oscillate between chaos and control.

‘It’s all about working with different domains: the real, the virtual, the unpredictable, and control. This way you allow the material’s own agenda to shine through. You must not force some kind of control onto the material, if you do, you miss out on some opportunities.’

Multiple types of wood

if you only use a few types of wood, you also miss out on some opportunities. The climate crisis is also a crisis of biodiversity. And if we need to cultivate huge areas with a single variety of timber to support wood-based construction, we run the risk of creating an equally huge crisis of biodiversity, Anders explains. This is his reason for experimenting with oak and beech in the research project Material Imagination, together with Associate Professor Niels Martin Larsen.

‘We want to rethink architecture: If the forests are to be our primary resource, they need to be able to make an impression on the way we live. What other actors are there in the forest? There are the animals, the air and the soil. Will one single type of tree work for them?’

However, the most profound result of Anders’ research is going to be a reduction in the amount of discarded wood.

‘We attack the problem using high tech tools: we use computers and digital fabrication to understand the complexity of wood. Today, we cannot really understand this complexity, which is why we just cut boards and throw away the rest.’

The rings and the twists

The trick is to allow the shapes of the wood to help define the pieces of wood we need.

‘A tree grows in a certain way because growing in that way is good for it structurally. It twists, it has rings. Nothing in this suggests that squares extruded lengthwise are best. This is something we came up with because it was easy,’ Anders says.

The timber industry is extremely advanced, so the reason is not any lack of technology in production. 3D scanning, GPS tagging and drone monitoring help optimise the processes. You assess the quality of the wood and produce slices and squares, while optimising things based on statutory standards.

‘But no one discusses these standards or whether our current machines and materials match the ways we want to live.’

New collaborations

However, from 2023, it will be mandatory in Denmark to carry out life cycle calculations (LCA assessments) for all new buildings Another step towards using more wood in the building sector. In other words, the world is slowly moving towards the place where Anders Kruse Aagaard already is: a place where wood is more dominant and is utilised far better than is the case today. Where the knots and branchings of the wood are not enemies we need to eliminate but rather conditions we have to work with.

‘The next step will be to expand our collaboration with design studios and with the wood and construction industry. We want to change ideas about how we ought to build – and from which materials.’

The revolution is bound to come – it is simmering in the workshops of Aarhus School of Architecture. And it will be good news for the air, the earth, the animals, the people – and the trees.