Geo Slate Research Book
Geo Slate - the value of a stone residue. Research on Geo slate started within Slot Lab and has been building upon the information that has been received through the period of time and from different interviewed and visited parties. Every chapter of the book will bring the reader through the development process as it was built up in the designer’s head. It is important to know that the research took it's turn in that or another way because the designer was facing different struggles or discover an interesting aspect during the research. In this book it would be visualized as the cause – and- effect relationship.
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3 quarry UK Lei Import
waste stre
material supply material properties material aestetics craftsmanship technique
surface simulations assembling
shape
tile shape desig
traditional slate tile
Introduction shape roof construction
roof curvature
3d Mod
specifics of construction assembling techniques
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4
5
7
value
eams process
mix design
prototyping
simulations
glazed ceramic recycled glass
Collaboration with TU Delft
prototyping
tile shape design 2.0
gn 1.0
deling
visiting the tile manufacture
prototyping
3d printing
About Slot Lab
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CHAPTER 1 Craft, technique and material Slatestone is a fine-grained, foliated, homogeneous, metamorphic rock, which is derived from a shale-type sedimentary rock composed of clay or volcanic ash through low-grade regional metamorphism. When expertly cut with a specialized tool, slate can be formed into smooth flat sheets of stone, which have long been used for roofing, floor tiles, and other purposes. Lei Import is the biggest importer of slate stone in The Netherlands. According to Rob Canton, Lei Importer’s company advisor, slate is very durable with special natural qualities that meet roofing standards. But despite these innate attributes, only 3% of the quarried material is usable to the market due to slate’s natural properties and production methods. Slate is both strong and brittle, requiring special craftsmanship to split the stones in just the right place. This process can only be done manually by experienced quarry rock splitters.
craft technique material
In addition to the low percentage of usable material, the process of splitting and cutting stones also consumes large amounts of water, which mixes with the production dust and results in 600,000 tons of unintentional subproduct. Upon its
understanding
production
more
process,
I
about began
slate the
and design
investigation to give a stage to slate and its mineral residues by designing an alternative material and replacing traditional craft with a clever technique.
sliced slatestone
slate stone large splitting
Slatestone structure
slate stone after industrial cut
splitters in action
Welsh Slate Quarry UK
dresser can adjust the shape of the tile during assembling, to make sure it perfectly fits the roof structure
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CHAPTER 2 Roof and Art of tile cladding Historical research of tile cladding (the assembly of tiles on a roof) shows similarities and differences between slate and ceramic. Due to slate’s lightweight character, tiles can have large overlaps the to
roof.
of
material Ceramic
minimize
the
without
cladding overlap
overburdening was
and
developed
weight
load.
Another design element of tile cladding considers the need to move around convex and concave surfaces of complex roof structures. Slate craftsmen typically custom split tiles on the spot, while ceramic tile cladders work with a system of various corner elements, as splitting ceramics is not a viable option. This research indicated that a new solution would need to solve the problem of tile overlap (to reduce the weight burden) as well as complex shape junctions. My first prototypes combined the aesthetics and simplicity of the slate assembly system with the
roof & art of tile cladding
Maas dekking
Koever dekking
Example of assembling of slate tiles on a roof
Hook system
Maas dekking. The slate is rectangular with the same size. The bottom layers can provide the thickest slates, because they get the most to endure. At the top, thinner slates are used. Koever dekking. The visible part of the slate consists of windows. The lower part of the slate has been cut out at an angle of 45 degrees. Leuvense dekking. Because of the open joint there is an increased risk that rain can be blown under the slates, and that the roof is therefore not completely watertight.
Leuvense dekking
minimization of waste using alternative materials. This eventually led to the development of the ‘harmonica principle’ which changes the spacing of the tiles, instead of the changing the actual tile. This
solution
was
only
possible
to
realize
through the use of 3D modeling programs. In
addition
to addressing the spacing issue,
I designed tile profiles to correspond with the concave and convex shapes of the roof.
tile placement study, scale model bottom
tile placement study, scale model top
Ceramic tiles overlap study
A modular tile system allows minimizing the waste during the assembling of the roof.
corner connection
layering of corner tiles
side ridge, layering of slatestone
top hip, layering of slatestone
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CHAPTER 3 Material research While developing the modular tile system, I carried out the Geo Slate material research. As slate cannot be locally sourced in The Netherlands, alternative sources were considered such as closed slate quarries, quarries of other natural stones, and the use of old slate tiles as a component of a new Geo Slate material. For the preservation of the Castle Schaesberg , an historical monument, it was important to preserve the aesthetic properties of the original tile material. Dry slate powder has the same color as slatestone. In initial tests, I mixed slate powder in two separate trials: with clay and with glaze. The clay mixture experiments were fired at 980°C and 1200°C; the samples fired at the higher heat were comparable to
nonporous
stoneware
samples
but
were
difficult to shape. The glaze mixture experiments produced a light, yellow-transparent color and resulted in a strong coating with no visible defects.
material research
ceramic tile 1:1 prototype, the slip cast was made with use 3d printing technique
dry slate powder has the same color as a slatestone
color research with waste pigments
Surface simulations In parallel to these experiments, I investigated ways
to
simulate
appearance
of
the
slate
in
‘layered
and
folded’
other
ways,
using
surface techniques in the ceramic. To simulate the color of slate, I referenced my previous research into sustainable glazing, including my experiments with ceramic industry waste. The final result of these experiments was a glazed ceramic tile consisting of 80% recycled material.
a simulation of a waterfall
recycled glass cast in molds with an imprint of slate stone to simulate the surface, this part of the project is done in collaboration with TU Delft Lida Barou Phd., Telesilla Bristogianni Phd.
detailed tile texture
tile textures 'layering' simulation
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CHAPTER 5 Mix Design, waste stone powders In the quest for finding the most sustainable solution, I carried out several additional trials. To combat the use of high firing temperatures, which produce CO2 emissions, I looked into materials which solidify at room temperature. Working with Dutch geopolymer technology experts, SQAPE, we determined that the chemical composition of slatestone was an excellent candidate for geopolymer technology. I cast the tiles using a 2-component silicon mold, which proved highly effective in reducing the amount of gas-produced bubbles, which are a normal result of this process, and which negatively affect the aesthetic appearance. This process allowed us to replicate the appearance of the tiles very accurately. As this process still required the use of non-local materials, I researched the quarries of other stones in the Netherlands. The most viable option was the sustainably operated
limestone
quarry,
Kunradesteengroeve.
Similar to slate, limestone extraction also produces a powder residue. But with very different chemical properties, limestone proved an unsuitable mixture
mix design waste stone powders
material for geopolymers. Mixing limestone in the glaze gave interesting results, it produced a light blue opaque color, which could be suitable for other applications. Finally,
I
researched
the
availability
of
used,
discarded slate tiles as a geopolymer mix material.
Geopolymers mix design at SQAPE
XRF slate powder
Preparation of a dry mix of Geo Slate
Geopolymer mix ready for a cast
Cast in a silicone form
Samples of geopolymer mix design with slate powder
casting samples in a metal form
Geo Slate after 24 hours, releasing from a cast
SQAPE laboratory in Wanssum
Kunradesteengroeve, visiting the limestone quarry side in the Netherlands
Glaze tests with limestone waste powder
crashed old slates were then sieved to achieve the right particle size for the aggregate
Broken tiles due to the transport and storage. One container is accumulated in a year.
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CHAPTER 4 3d modeling & shape design As briefly mentioned in Chapter 2, 3D modeling helped to analyze the roof surfaces to see how the tile profile and modular system would behave in a complex system containing many convex and concave shape junctions. It also helped to determine the fewest number of necessary profiles, which was four, two of which are mirrored corner elements. In addition to the functional benefits of tile spacing, described in Chapter 2, the technique also resulted in a more dynamic overall appearance. After creating a 1:1 scale model, I worked with rapid prototyping company, Concr3de, to simulate the surface of the slate tile material. I proposed to replace the typical concrete with stone powder and we tested this at 10% of the total content. The resulting material was not functionally viable, but we were able to produce a material that had the desired look and feel for the Geo Slate.
3d modelig & shape design
close up, 3d model of the roof, Slot Schaesberg
With
further
research,
rapid
prototyping
has the potential for small scale production of
materials
for
restoration
processes.
3d model of a sector of the roof, Slot Schaesberg
laboratory Concr3de
During the printing process the ‘activated’ layers revealed
full lessen
full extention
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CHAPTER 6 Visit to the tile manufacture In order to understand the viability of this research on a production scale, I visited Monier, the biggest tile manufacturer in The Netherlands. The
perfected
production
process
requires
specific steps and materials, including 4 support molds for every manufactured tile. While the researched Geo Slate techniques were interesting to Monier, we also discussed the hurdles to production: adaptability to standard processes and
approval
by
the
German
development
team, a process which could take up to 5 years. The focus of my further efforts is towards designing a modified tile that suits the existing manufacturing process. To this, I add design elements that improve the ease of assembly and water tightness of the system.
BMI Monier tile manufacture
Waste bisquit clay is reused in a new production of roof tiles
drying supports
production line
drying supports
manufacturing process BMI Monier
high resistant ceramic kiln supports
Each kiln support has a unique design, that allows the homogenous fire of a tile
one part of the steel press mold
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CHAPTER 7 To be continued, collaboration TU Delft In July 2020, Studio Mixtura started a collaboration with TU Delft on the Geo Slate project to investigate the possible sustainable geopolymer mix substituting the natural slate stone. The intention of the collaboration is to find the best mix design and optimize it as per the requirements of density, strength and volume stability of Geo Slate.
Collaboration TU Delft
Geo Slate Samples by TUDelft
Geo Slate mix design samples after 1 day of room temperature treatment.
Mix design with different ratios of slate powder, research performed by Bei Wu, PhD and supervised by Dr. G. (Guang) Ye, Associate professor of TU Delft
about SLOTLAB
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SLOTLAB - sustainable renovation of Slot Schaesberg SLOTLAB, led by Simone de Waart and Machiel Spaan, is a project that examines how to rebuild existing structures with modern building technologies, and how to do so with circularly processed, locally deployed materials. Within this scope, Studio Mixtura is collaborating with architectural studios on a renovation proposal for the Castle Schaesberg in the province of Limburg, The Netherlands. modern
How
technology
crafts
and
together
shape the future of heritage.
Challenged by the reconstruction of a 17th-century castle farm, four designers are looking for new materials and production methods for application in cultural heritage. With the aim of feeding the existing building practice with ideas on how to do it differently.
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5
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SLOTLAB is a research project into innovative construction techniques inspired by traditional crafts. The reconstruction of Schaesberg Castle, a castle ruin in Landgraaf serves as a backdrop and source of inspiration. The Schaesberg Castle tower is being rebuilt by the Schaesberg Castle Foundation
using
old
crafts
and
materials.
SLOTLAB connects designers with the construction industry
and
education
through
five
mirror
projects, each of which is redesigning a part of Slot Schaesberg. Challenged by the reconstruction of a 17th-century castle farm, five designers went in search of new local materials and production methods for use in cultural heritage. SLOTLAB researches the circular application of local materials, traditions, crafts and technologies. With the found raw materials and application possibilities,
the
designers
develop
appealing
new building components that are part of a long tradition of craftsmanship and innovation.
Lab 1 -FIREPLACE by Thom Schreuder In the LAB FIREPLACE, architect Thom Schreuder is researching how the characteristic fireplaces of Schaesberg Castle can be brought back to life with contemporary 3D technology. With the aid of 3d scans and old recording drawings of the fireplaces (by historian Mulder), Thom has modelled both the old situation and the parts to be reconstructed in a computer model. His model is the basis for designing fireplace prostheses and fitting pieces that “repair� the old remnants. Old and new are thus united. In collaboration with 3DMZ and Concr3de, he is developing a printing method in which sawdust from the local Kunrade quarries is used as an additive. The 3d models of the stone prints are digitally processed so that these renewed parts of the fireplace form an open structure. With the use of the original material and by showing the possibilities of digital new techniques the fireplaces are partly getting their old shape back. (Picture 1,2)
Lab 2 -ROOF by Werkstatt Architechts In the Lab ROOF, the Werkstatt architectural firm reconstructs the “helmdak” of the central gate tower at Schaesberg Castle. A large number of massive beams, sawn from large oak trees, made the space under the roof impenetrable. Werkstatt wants to make this space accessible so that visitors can experience the roof construction up close. The architects are inspired by the ideas of wood constructors who developed innovative wood constructions from composite parts of wood, so-called “laminated wood constructions” in the early 19th century. Several thin layers of wood are assembled into a thick, strong beam using smart connections of steel or wood. This demountable construction is circular. In the mid-19th century, this pioneering work was overshadowed by the advent of wrought iron structures. Werkstatt takes up the ideas of the 19th-century engineers and combines their ideas with the most modern wood construction techniques. The new tower roof is a tribute to two centuries of innovation in wood construction and bridges the gap between new and old. (Picture 3,9)
Lab 4 -SLATE by Studio Mixtura In the Lab SLATE, Studio Mixtura developed a new modular slate for the roof of Schaesberg Castle as an alternative to the traditional slate that covered the roofs of historic monuments, churches and castles for centuries. Despite the slate’s water-resistant qualities and long life span, almost all slate quarries in Europe have been closed in the past century. The production process is very inefficient and not sustainable; only 3% of 100% quarry material is sold on the market as slate. The material for the new slate comes from the residual flows of slate extraction and other mineral raw materials from the Dutch soil. The residual material remains in the quarry after the slate extraction. During production, water is used to settle the slate in the air. The combination of dust and water results in sludge waste that is collected in filters. Every year this leads to 600,000 tons of sludge waste per quarry. Together with several partners, Mixtura investigated the possibility of using this sludge waste to develop a new slate tile, processed in a modular system. (Picture 6,7)
Lab 5 -VR by Ron van den Ouweland The Virtual Reality LAB is Slotlab’s connecting lab. Within it, the programmer and designer Ron van den Ouweland visualises the experiments, mock-ups and scale models of the other labs in a coherent way that appeals to the imagination of a viewer. In a virtual environment of the old castle, the results of the labs can be seen at the place in the building where they belong. This way, the innovative applications can be read at the location of the Schaesberg Castle. With the help of an abstract representation of the Castle in Virtual Reality, it is possible to show the process and results of all the LABS. The VR lab makes the tension between the past and the future tangible and stimulates the dialogue about innovation and renovation in heritage. (Picture 5,8)
Lab 3 -LIGHT by Teresa van Dongen For the Lab Light, designer Teresa van Dongen is researching how she can use microbes from the moat as a source of energy for a contemporary lighting installation. Since 2016, van Dongen has been working on light installations that get their energy from electroactive organisms that live in the bottom of ditches and lakes. For the Lab Light, Teresa took samples from the castle moat of Schaesberg Castle and managed to connect a light to the sludge. She is developing the special electrode on which the bacteria can deposit their energy in collaboration with the University of Ghent. The eventual light installation refers in its design to the cultural heritage of Schaesberg Castle. The oil lamp with its fluid reservoir is an important source of inspiration in the design process. To include the old crafts that were customary in glory days of Schaesberg Castle in her design, she works together with the blacksmith on the location of the Castle itself. (Picture 4)
Conclusion This book is delivered as an inspiration, and to show the potential of design research on sustainable materials.
Colofon Text: Daria Biryukova | author Jessica Smarsch | copyeditor Photography: Bei Wu Phd. TU Delft Daria Biryukova Lei Import Timeframeproject Jeroen van der Wielen Partners of the project: Slot Lab, M3H Architects, Material Sense LAB, Lei Import, SQAPE, TUDelft, Kunradersteengroeve Sponsors: Creative Industries Fund NL, Slot Lab (Iba Parkstadt), Province Limburg