Digital Craft in Architecture

[Hempcrete Blocks/DCA]

By [Mohd Hafidz Hazri Bin Mohd Razali]

Tutors [Adam Holloway] | [Elliot Rogosin] | [Edoardo Paolo Ferrari]

MA DIGITAL CRAFT IN ARCHITECTURE Oxford School of Architecture

ABSTRACT/ INTRODUCTION

Designing building structures and components is the most essential part of making an idea tangible. This project aims to understand further about a material that can be considered as a substitute for typical material used in construction. Despite having a substantial history with multiple uses of the material. Hemp, or in this project will be focusing on hempcrete, is still not considered a conventional material to construct a building. The embodiment of the idea to promote better architectural sustainability juxtaposes with the traditional method as building construction is one of the prominent contributors to carbon emissions. Its unique criterion of durability, flexibility, economical, and unorthodox way of curing are the root of to study of the material. Nevertheless, even with a comprehensive research paper on the study of hempcrete, this project tweaks the methodology of casting and experimenting with the basic geometry, mixing, binding, curing, and interlocking. Through hand-to-hand experience with the material, practical experience suggests otherwise of what is being emphasized by the theoretical research paper such as the ratio between the binder and hemp, and also the curing time.

CONTENTS

Chapter 1: [Manifesto]

- Manifesto

- Collage

Chapter 2: [Parametric Vase Modelling]

- Investigation

- Process

- Product

Chapter 3: [Case-Study: Metropol Parasol, Seville]

- Investigation

- Process

- Product

Chapter 4: [AR+ Stacking]

- Investigation

- Process

- Product

Chapter 5: [Manufacture and Toolpaths]

- Investigation

- Process

- Experience

- Simulation

Chapter 6: [Radical Reintepretation]

-Investigation

- Context/ References

- Process

- Studies

- Tests

- Radical Reinterpretation 1:5

- Radical Reinterpretation 1:1

- Final Output

CHAPTER 1

[Manifesto]

- MANIFESTO

- COLLAGE

MANIFESTO

What if?

Circular economy of materials in architecture

The waste generated in nature is not dormant, it nurtures architecture and architectural material libraries. The material both begins and ends with nature and remains in harmony in between. Architecture need not be exclusive; waste from other industries can feed material in architecture and upon decomposition such matter can nurture the surrounding.

Both craft and the material can be sustainable only when they are locally rooted

Architecture should mainly depend on material that is abundant in its context, to the craft and culture surrounding it. The realization of natural material would critically depend on reducing the inbound and outbound transfer of material from its context and in increasing the dependency on local craft, and its techniques passed on by experienced ancestors.

Traditional craft will remain till the end

Any newly introduced atypical material would depend on typical crafting methodologies adapted to its material properties to create novel joinery techniques. Past craft feeds and evolves into the future design.

Detail can only be driven through the material

The choice of the material will dictate the design process, the detail can be inspired but will always be manipulated by the properties of the material chosen. It is avantgarde but also in harmony with the natural precedent.

Design will only advance in its attempts to supersede it

Any newly introduced atypical material would depend on typical crafting methodologies adapted to its material properties to create novel joinery techniques. Past craft feeds and evolves into the future design.

CHAPTER 2

[Parametric Vase Modelling]

- INVESTIGATION

- PROCESS

- PRODUCT

INVESTIGATION

Digital 3D production using Rhino3D and proceed to cut using a laser cut machine and integrate between digital fabrication and manual assembly without adhesive/glue.

The material choice for this project shall be plain paper, ranging from 100 GSM to 300 GSM since paper has the right amount to bend while maintaining its strength credibility.

The main challenge of doing this project is to have consistent workmanship as the tension between each jointing will loosen overtime.

PROCESS Thoughts Challenge

TRY AND ERROR FOR IMPROVEMENT PROCESS

First Trial:

a) 300 GSM Paper

b) Paper thickness is more than the opening that was produced by the laser cut machine

160 GSM PAPER

Second Trial:

a) 160 GSM Paper

b) The “flapper” size is too short to put the joinery in place

Even though it was mentioned that the 160 GSM paper could join more flapper as they are considered as more flexible compared to 300 GSM paper. The limitation to join the flappers together can only be extended to three modules. Every curve on every level produced more tension compared to the smaller/lesser diameter of the vase. The intervention of another joinery method such as stapling the corner as additional support to give better strength credibility is compulsory at the end of the process of creating the vase without any adhesive.

ILLUSTRATION OF TENSION FORCE APPLIED BETWEEN THE JOINERY TO HOLD THE VASE TOGETHER

Joinery started from the edge as it has a medium diameter size compared to the other edge.

Final Trial:

a) 160 GSM Paper

b) Longer “flapper” sizes can hold the joinery in more modules.

Stainless steel staples held the edge joinery as they were the last piece of the joinery with the highest tension to bear.

The middle flappers gradually gets harder to join as more tension are builds up between joineries.

- PRODUCT CHAPTER 3

- INVESTIGATION

- PROCESS

[Case-Study: Metropol Parasol, Seville]

INVESTIGATION

Thoughts

The waffle timber jointing is probably the most efficient way of jointing more than two timber pieces at the same time as the load transfers equally to the central body of the structure. During the scaled model making, choices of material played a huge role. This matter can be applied to real-life construction as well. It can be observed that the friction from the chosen material will determine the strength of the jointing. More strength from each jointing is equivalent to a higher overall structural strength.

Preliminary Process:

a) Laser cut on 5mm thk. foamboard

b) Carefully dismantling products from the frame work as the material can be quite fragile

Midway Process:

a) The Assembling process took more time than expected as physical model components are not labelled digitally

b) Reassembling process - referring to 3D model

Final Process:

a) Final adjustment on the physical model

b) Documentation.

- INVESTIGATION - PROCESS - PRODUCT CHAPTER 4

[AR + Stacking]

INVESTIGATION

Rhino3D| Grasshopper | Fologram | Hololens

This chapter aims to gain the experience of using mixed reality making between human touch with robot-assisted precision. Modelling a simple but novel serpentine brick wall with specific angle rotations at every corner using Rhino3D and scripted/automated using Grasshopper. Nevertheless, despite having been assisted visually by the VR headset, the human workmanship is not to be miscalculated or underestimated as one inaccurate arrangement will affect the top layers. Having said that, mixed reality making still helps in terms of precision and time reduction.

PROCESS Thoughts

Preliminary Process:

a) Create equal segments of curvature on Rhino3D

b) Create the first script on Grasshopper to determine the object that is going to appear along the curvature.

Midway Process:

a) After reaching all criteria of the assignment brief, put the final script to synchronies with Fologram

b) Connect the Fologram with the Hololens

Third-person view while arranging the bricks with assisted with Hololens headset while synchronised with Grasshopper Top view of the final product. The QR code is the base of starting the brick layering

First-person view of arranging the bricks designed in Rhino3D, the white box layers represent bricks position

Side view of the final serpentine wall. Product of mixed making between human touch and virtual reality.

CHAPTER 5

[Manufacture and Toolpaths]

- INVESTIGATION

- EXPERIENCE

- PROCESS

- SIMULATION

Thoughts

Computer-numerical control or CNC is one of the most prominent skills that we learned while developing the project. CNC products are usually precise if nothing interferes with the process.

Even though CNC machines are accurate, human interference with the outcome sometimes is a must. This chapter will emphasise the milling technique of CNC machines and how to minimise material usage with multiple joinery at a single point.

Three joineries in one point

Three module join without nails

Accurate angled cut by CNC machine

1. Upload file from Rhino 3D to Fusion360

2. Set up the 3D model with fixed size stock

3. Ensure the height of the model and stocks are correct

7. Click on “Adaptive” function and select face contour

8. Select 3D model faces that need to be milled

6. After the mill has been set up, the interface should show something like this

4. Change the mill type and size

5. Select the mill size that is suitable for face contouring

9. Ensure the 3D model height are correct

15. Adjust the milling to Ball end mill with a smaller diameter to provide a fine edges

10. Use “Simulation” function to prevent error

11. Click the play button to see the start and end process of face contour

14. Set up for finishing movement set

13. Re-simulate to see the difference of mill movements

12. Adjust the maximum roughing steps and Fine Stepdown

16. Ensure the step-over value is correct to prevent from the mill skipping some areas

17. Re-simulate the process to prevent from error during CNC production

- FINAL OUTPUT CHAPTER 6

[Radical Reinterpretation]

- INVESTIGATION

- CONTEXT

- PROCESS

- STUDIES

- TESTS

INVESTIGATION

The process of strengthening hempcrete bricks is proportional to the process of rammed earth material. The density and porosity between the 6mm hemp particles and the air gap correlate with the general strength of the material to comprehend compression, tensile, and flexural strength. Higher and equal distribution of compression force on the material results in better durability of the material. However, there are several challenges on how to compact the material, specifically, to form a brick with an unconventional geometric shape as what has been proposed in this project. The intended brick shape of the hempcrete has undercuts / negative values under the formwork perimeter which is impossible to cut with the available CNC machine technology that is being used while making the product. Furthermore, since the brick shape is triangulated, it has uneven compression force distribution, which will lead to weak points on the brick’s perimeter. Other than that, the curing process of hempcrete also varies, highly depending on the precision of mixing and the environment temperature.

LIMITATIONS / CONSTRAINTS OF HEMPCRETE BRICK PROCESS

Having said that CNC machine cannot mill at omnipotent direction (milling at a negative surface). The intended design will have to rely on foreign pieces to create as sub moulds. The sub moulds will not only help to create the intended shape for the project. But, it will also give a proper formwork to shape the complex geometry brick so that the ramming process can take place properly with equal distribution of compression to the hempcrete. The sub moulds will be held by a second person while the ramming process is taking place so that the compression force won’t force the sub moulds to fall off from the core mould by its force pressure transfer.

ILLUSTRATION OF RAMMED HEMPCRETE SUPPORTED WITH SUB-MOULD

Hempcrete mixture added after sub-moulds are positioned

Sub moulds added to give solid surfaces to mould the negative areas

Remove the moulder walls and hempcrete with negative surface areas can be observed

Core mould

Typical ramming process

Multiple control point

Weak compression point

Equal compression force distribution

Uneven compression force distribution

High difficulty to control compression point manually, especially at the negative surface areas

Sub moulds lifted after hempcrete took its solid shape

Turn the moulder upside down

Material Comparisons

Casting material is ubiquitous in built environments. However, each material has its unique properties which highly depending on the reinforcement method and composite materials.

Why Hempcrete?

Despite having numerous advantages over other orthodox material, hempcrete has one big flaw.

Durability:

Hempcrete acts as a material where it is consistently being compressed on load application. However, the performance capability to withstand compression and flexural strength is subpar compared to concrete and rammed earth.

Question?

How can we improve the material strength with different types of techniques or mixtures and adapt a more complex shape using hempcrete?

Common Reinforcement Material

Main Composite material Material

Fibre - Hemp - Hempcrete brief History

10,00020,000 BC

2000 BCE

1ST - 15TH CENTURY

16TH - 20TH CENTURY

BC

MESOLITHIC AGE // 9000

Sheep wool discovered

NEOLITHIC AGE // 6000 BC

BRONZE AGE // 2500 BC

Northern Europe

Starting to developed Nettle Cloth

ANCIENT CHINA // 2000 BC

Ancient China started to grow hemp plants

ANCIENT EGYPT // 2000 BC

Ancient Egyptian started to grow hemp as well, but mainly used for rope

ANCIENT GREEK // 600 BC

Uses of linen based on flax

ANCIENT ROMAN// 200 BC

Discovery of Pozzolan Material Succeeded to construct a concrete bridge

Fibre technology growth rapidly as they were starting to produce textile

MEDIEVAL ROMAN// 1ST CENTURY

Hemp Fibres became a very important material

MEDIEVAL EUROPE// 5TH CENTURY15TH CENTURIES

Hemp Fibres started to grow all over Europe

AMERICA// 5TH CENTURY16TH18TH CENTURIES

ENGLAND// 18TH CENTURIES

The American colonies started to grow hemp to get the fibre

INDUSTRIAL REVOLUTION// 18TH CENTURIES

FRANCE // 19TH CENTURIES

First house that built with precast concrete

The pioneer country to discover hempcrete Flax and linen production dramatically collapsed

21ST CENTURY

Hempcrete uses are getting more popular at a global scale due to its uniqueness properties and its benefits for its environment

AMERICA// 5TH CENTURY- 16TH - 18TH CENTURIES

ENGLAND// 18TH CENTURIES

FRANCE // 19TH CENTURIES

Discovery of ropes using hemp helps the Roman to enhance their military strength and boost their economy due to trade and sailing

MEDIEVAL ROMAN// 1ST CENTURY

ANCIENT ROMAN// 200 BC

ANCIENT GREEK // 600 BC

They started to introduce fibre to built environment

ANCIENT CHINA // 2000 BC

ANCIENT EGYPT // 2000 BC

PROCESS

One main mould with supported brackets at the perimeter alongside three sub-moulds that were positioned at every corner of the main mould to cover the negative value of the desired shape. The three submoulders are embedded with wooden pegs (two wooded pegs on two surfaces) to create a consistent mould shape.

STUDIES

Geometry Morphology

The manipulation of a basic geometry arrangement to a more sophisticated polygon

Geometry Morphology - Automation / Scripting

Randomise the hexagon hempcrete brick base sizes and thickness

Typical cube in repeated arrangement

Cube angled to 45 degree

Angled cubes arranged in a repeated pattern

Cutting plane applied at 60% of the cube size from a flat level.

Pyramid shapes observed at the base of the arrangement

Hexagonal shapes are formed from the top view of the repetitive arrangements

Non manipulated geometry.

Grasshopper scripting facade variation

Geometry Morphology - Variation

Geometry patterns for the brick design depend highly on the cutting plane level of the repeated cubes arrangement. The cutting level will determine the quantity uses of material in one process of making the hempcrete brick.

Geometry Morphology - Variation

Having said that, the level will also dictate the surface area of the internal wall since the arrangement and cutting level create two different surfaces from external and internal views. A higher cutting plane level will also create higher material robustness to withstand compression.

Curing Methods of Hempcrete Tests

3 types of curing methods for the hempcrete bricks were tested on-site including the curing method supported by mechanical systems such as pottery kiln and oven. The methods were tested due to the knowledge gap on what temperature is the best for the hempcrete to be perfectly cured hence providing good durability.

Hempcrete Recipe Tests

Three types of binder ratios were used during the hempcrete mixture to study the least brittle material texture once fully cured. The ratios set out were tested on three typical brick prototypes and cured naturally without any mechanical intervention. The tests were conducted on similar brick size with similar curing method.

Technique

Process

Considering the time limitation to conduct the studies, we observed that the hybrid curing method is the best application to apply for the hempcrete curing process. The hybrid curing method consists of 8-10 hours of natural drying process and a gradual increase of mechanical-assisted drying process which changes every 3 hours.

The natural drying process took place where the environment’s average room temperature recorded was 15°C - 18°C within 3 days. After 8 hours of natural curing process, the hempcrete brick was then brought to a pottery kiln and set at 70°C within the first 2 hours. The kiln temperature increases gradually every 2 hours until it reaches 115°C before the curing process is completed.

RADICAL REINTERPRETATIONS

Introduction

The main context of researching and testing the hempcrete is to radically reinterpret building structures or components. In this project, the reinterpretation subject is the Mäusebunker, located in Berlin. The Brutalist building was designed by the German architects, Gerd and Magdalena Hänska. Mäusebunker functioned as an animal testing laboratory facilitated by Universität Berlin. The building was then shut down in 2020 after its final function as the Charite’s Research Facility for experimental medicine (FEM). The concern from public view over this monument is the looks of the brutal facade and concrete create the feeling of threat and partially looks abandoned. The conceptual framework to reinterpret the building is by promoting flexibility, adaptability, modular, and cellularity. The uses of hempcrete help in terms of the breathability of the inhabitants and will enhance the comfort for the users. Also, while experimenting with the properties of the materials, the project will cover how the manipulation of basic geometry can improve the facade of the building.

Descriptions of the Brutalist structure

FOREBODING DESIGN!

BULKY THING!

LOOKS ABANDONED

Article Credits:

CONCRETE CLAD BUNKER!

[ Design of Flat Vaults with Topological Interlocking Solids ]

by Francesca Lecci etAl. (2020)

NIGHTMARE TRANSFORM INTO MATTER

THE SCARIEST BUILDING IN GERMAN POST-WAR HISTORY!

MONSTROUS!

FEELING OF THREAT!

A HUGE CONCRETE MONSTER!

Abandoned Berlin (2020), Mouse Bunker

Declad (2021), The Mousebunker by Gerd and Magdalena Hänska Guiding Architects (2017), Brutalism in Berlin – a building cult Dezeen (2021), Nathan Eddy documents under-threat brutalist Mäusebunker building in Battleship Berlin film

[Mäusebunker]

Hänska

by Gerd and Magdalena

Designboom (2023), Berlin’s Brutalist ‘Mäusebunker’ building listed as a historical monument

Scaled Model 1:5 - Window

It was mentioned in the project brief that it required to interpret any fragment from the radically interpreted building with a 1:20 to 1:50 scale. However, due to the limitation of structural detail in the building. This project decided to take a 1:5 scale for a window detail of the interpreted building instead. The building component was chosen as a scaled model prototype since it has a unique feature that can bring more probability towards the idea of interpreting this building. Other than proposing changing the material, the scaled model also offered how can the window bring more purpose to the building, rather than just being solely a functioning facade and opening.

[M

[M

SOSBrutalism (2023), Gerd Hänska / Magdalena Hänska / Kurt Schmersow: Central Animal Labs “Mouse Bunker”, Freie Universität Berlin (Zentrale Tierlaboratorien “Mäusebunker”) , 1971D–1980

SOSBrutalism (2023), Gerd Hänska / Magdalena Hänska / Kurt Schmersow: Central Animal Labs “Mouse Bunker”, Freie Universität Berlin (Zentrale Tierlaboratorien “Mäusebunker”) , 1971D–1980

Mrmoderneregional (2020), Interior views: Mouse bunker & Comonument

by Gerd and Magdalena Hänska

by Gerd and Magdalena Hänska

äusebunker]

äusebunker]

PROCESS

Problem Statement

Despite having a large glass panel on the extruded pyramid from the slanted wall, the main problem for this particular structure fragment on this building is; the lack of direct sunlight fenestration to the interior building. The general indoor atmosphere has also been reported to have low natural light and ventilation quality. The intervention as proposed from the scaled model can tackle this issue by providing a twosided glass panel on two pyramid sides and also by using hempcrete, the natural ventilation can naturally flow as it is a porosity material.

One sided glass panel

Indirect sunlight penetration to the indoor

PROCESS

Procedure

The procedure of modelling the scaled model is similar to the hempcrete process. Starting from creating the mould made by CNC machine and pouring plaster into the mould. Next, remove the plaster from the casted mould while preparing the window framing by using a 3D printer. The final step is to ensure the plaster blocks fit into the framing, held by interlocking method (held using compression and frictional force).

Two-sided glass panel

Scaled Model 1:1 - Wall

The structure fragment chosen to be reinterpreted in this project is the slanted wall panel. The initiative took place due to the high rigidity of the panel looks from outdoor and indoor experiences. Other than the unique material usage for the wall panel, the reinterpretation was also considered due to the complex geometry of the brick panels to the facade and interior room, thus, giving a whole new experience for the users of the building, also giving a new impact to the architecture surrounding

[M

by Gerd and Magdalena Hänska

äusebunker]

PROCESS

Three wooden planks with 220mm height were designed at the perimeter of the core moulder to support it during the ramming and curing process. Three screws were embedded on each side of the perimeter to prevent it from breaking to withstand the impact during the ramming process. Since the workmanship on the jointing is not highly precise, sealant using plaster was added in between each gap of the jointing to prevent water loss during curing.

PROCESS

Process 1: 3D printing submoulder

Process 2: Combine 3D printed and laser cut products

Process 1: Laser cutting sub-moulder support

Process 3: Assemble CNC products to form a core moulder

Process 4&5: Put the sub-mould products at every corner of the core mould. Apply sealant to prevent leakage and lubricant on every surface of the core mould to ease the hempcrete removal.

Process 1: CNC core moulder and its support

Process 6,7&8: Insert the mixed hempcrete from processes 6 and 7 into the core mould, ensure the sub-moulds are holding tight at the corner, and ram the hempcrete with equal compression on the surface area.

Process 8: Detach the core mould from the hempcrete brick with care after 8 hours of naturally cured

Process 8: Insert the hempcrete product into the pottery kiln and set the temperature accordingly.

Complex Hempcrete Brick Geometry Mould Tests and Synthesis

It is undeniable that using hempcrete has environmental and structural benefits. The material has unique properties and not many materials can display similar performance. The idea of integrating an ambiguous material such as hempcrete with considerably low tolerance geometry as proposed in this project has its downside rather than any particular advantages.

The hempcrete brick undercuts are the hardest part to ram as they are not directly hit in the ramming process. The shapes only took place due to compression from additional sub-moulds.

During the curing process, we observed that the hempcrete brick has to be cured at a gradual temperature so that the mechanically assisted heat can be equally distributed from the inner core of the hempcrete to the outer surface. Drastic temperature difference will create a very brittle hempcrete brick with an overly dried texture (hemp, lime and water did not bind properly)

Even with sharp edges moulder, hempcrete is not a well-defined material. The edges of hemp will not give a sharp point due to the varieties of hemp size in one mixture. The edges needed to be adjusted manually after opening the moulder.

Advance Geometry Undercut Mould With Module Variation

Since the formwork design limiting the capability of creating an equal compression force, the intended shape of the brick also became a constraint for it to become a solid material. To produce a more well-defined shape of the brick. Sub-mould to infill the negative values/undercuts where the CNC machine is incapable of milling the area. 3 sub-moulds with the shape of a smaller pyramid in comparison with the main core will be placed right at the intended level, supported with additional components to provide consistent levelling. Direct execution of compression force to the center of the core mould will transfer the feedback force to the sub-mould and the sub-mould will hold the shape together.

Limited capability for CNC machine to execute undercut properties

3 sub-moulds on each mould to infill the core mould undercut as additional support

Capable of discovering four unique modules on the flat rectangular panel. Module A

Front View

Improved Stepped Mould

We were inspired by Carlo Scapa’s stepped detailing, which gave us the language for the stepped decorative elements in the design. At the same time, different shapes were created by combining different modules of the mould. A number of suitable units were selected to be combined in order to create a coherent connection between them.