HydroMorphology Yasmina EL HELOU Tutor - Marcos CRUZ Institute for Advanced Architecture of Catalunya Master in Advanced Architecture Barcelona, Spain - 2019 Thesis presented to obtain the qualification of Master Degree from the Institute of Advanced Architecture of Catalunya
Abstract
09
Preface
13
I Water Scarcity
19
a. Water Scarcity and Desertification
20
b. Water Scarcity and Urbanization
28
c. Fog-laden air - A potential solution for water scarcity
32
II Surviving Water Scarcity
35
a. Learning from Nature
36
b. Enhancing accessibility to natural resources - Human Intervention
40
III Hydro Morphology System
51
a. Redefining the traditional courtyard
52
b. Designing the “Fog Catching� Building
56
c. Performative urban materiality: porous concrete - Current Application
62
d. Performative urban materiality: porous concrete - Experimental approaches
63
e. Designing the Porous Concrete Tile
66
f. Designing the porous concrete Tile Build Space Residency extension
78
g. Multi-scalar design strategy - channeling and hydro-mobility
84
h. Water collection and future use
88
Conclusion
00
Annex
00
References
00
04
Index
05
06
Abstract
07
08
Abstract
Semi-arid and dry sub-humid areas are places of the world where water is scarce but vegetation growth and human settlement are still possible. These regions are highly expanding due to climate change and the rise of population density, and therefore, their urbanization keeps growing from a year to the other. Water demand is growing while water supply is decreasing with the expansion of cities. Nonetheless, fog-laden air presents hope for another kind of water gathering in some specific dry places. Inspired by species capability of surviving the driest environments, and the fog catching mechanism, this project focuses on finding efficient ways to harvest water for desert cities.
The project provides access to water in previously water-stressed areas, combining materiality and form in order to generate performative solutions to this end and solve ongoing issues.
Hydro Morphology converges to porous concrete and its ability to catch water droplets into its materiality and, later, harvest it through the building cladding system, working in a multi-scalar and optimized method. To enhance this process, building design can respond, creating wind turbulence and allowing the foggy air to be captured.
09
10
Preface
11
Water is the people’s main source of life. Many cities throughout history, and around the world have settled close to natural water bodies such as rivers, seas, water sources, or lakes. People use water for drinking, agriculture, transportation, domestic purposes, hydropower generation, etc.
They are often covered with sand, rocks, and more rarely, ice. Some of these lands contain so little water that life is almost improbable; hyper-arid deserts. Others have less harsh environments and go from arid, semi-arid, to dry-sub-humid deserts. The latter welcomes the most amount of water during the year. Plants and animals are able to survive in these areas, and of course, humans do too.
However, as cities grow, and population density and demand increases, water becomes even more valuable and requires more attention and preservation. Water shortages and scarcity are consequently actual issues that one cannot overlook and should consider in his everyday life.
Growing up in a Middle Eastern country has made me concerned about the issue of water and its importance, especially in large settlements and cities. Semi-arid areas population density is expected to grow from 1.5 billion people in 2010 to more than 2.0 billion in 2050, whereas dry sub-humid from approximately 0.8 to 1.2 billion in the same timeline.
Lands are divided into multiple categories depending, among other parameters, on the amount of water (rainwater, precipitation, humidity, etc. ) they contain. Deserts are places of the world where usable water is more limited than any other region.
This rise of population in deserted areas is mainly related to the industry, immigration, mining, job opportunities, and,
City settlement around a water body, The Nile - Cairo, Egypt 12
Preface
less often, to tourism. Sub-humid cities such as Cairo in Egypt or Muscat in Oman see their population density augment considerably and therefore their environment and water availability regress.
The project will focus on very specific climates and locations. It will take into account many parameters; either natural (humidity, fog, rainwater, etc. ) or controlled (wind power). Hydro Morphology is a multi-scalar project focused on material study, building typology, and environment.
Planning a solution in the long term should be a priority in the development of our cities. So how, when it comes to water management, can architects, designers, city planners, and engineers consider the remarkable growth of these cities? Populations will keep growing, and consequently, water demand. This project will accordingly focus on water availability (and unavailability) in specific areas and will try to create a system that constantly collects water for the city and its inhabitants. Observing nature’s behavior in such harsh and dry deserts lets us realize the capacity of organisms to survive. It is possible to create projects which evolve according to principles similar to those found in nature. The system’s complexity of cacti, succulent plants, and various animals (such as desert lizards and beetles) shows a capability to harvest water, store it, and use it in times of extreme dryness. How can biomimicry in architecture generate buildings that enable the users to survive in times of drought?
13
Acknowledgments My sincere thanks go to my thesis advisor, Marcos Cruz, who has given all his support during the whole process. Marcos’ extended culture in architecture, biology, design, and so many other fields, as well as his curiosity to learn from my personal research, was exceptionally helpful and encouraging. The writing and structure process of the project would not have been possible without Mathilde Marengo, Head of Studies, who participated continuously in the coordination of the investigation and development of Hydro Morphology. Additionally, I address a special thank you to biologist Nuria Diaz who expressed confidence and assistance throughout the year. I am also grateful for the Institute for Advanced Architecture of Catalunya, and its whole Fab Lab team who help throughout the fabrication process and allowed me to take advantage of the tools, robots, and machines. And finally, I thank my classmates and especially the students of BioM-A who were always working with me and giving ideas, references, and suggestions for my thesis.
In specific conditions, where fog; a thick cloud of tiny water droplets suspended in the atmosphere, is ubiquitous, the process of catching these water droplets from the air is possible. The wind allows the droplets to go to a certain direction and get caught onto a net. This process is useful in dry areas where water can barely be found on or under the ground level. The project envisions a more complex fog catching system that replaces simple nets with actual concrete. Concrete can be pervious, and therefore have considerably big holes allowing water droplets to pass through. So how can a concrete tile (accompanied by a winding input) perform as a fog catcher? This question is followed by multiple experiments on porous concrete leading to the understanding of the impact of a fog-laden air on this material. The results revealed the capacity of the porous concrete to catch the water and the simulations that followed created a basis for future development.
14
Preface
15
16
Chapter I - Water Scarcity
Photo by Thomas Vuillemin 17
Water Scarcity
I a. Water Scarcity and Desertification Deserts: area, often covered with sand, rocks, or ice where there are very little rain and not many plants. Depending on different criteria; such as temperature, humidity, precipitation, and vegetation, deserts are divided into different categories. The latter categories define whether life is possible in the designated areas, whether it’s difficult or, whether it’s nearly absent. It is important to study the deserts and their specifications for a better understanding of the area this project focuses on, and for better optimization of its efficiency. Deserts can, therefore, be hyper-arid, arid, semi-arid, or dry sub-humid. Some of them can barely accommodate life while others ( in this case semi-arid and sub-humid areas) are more apt to welcome vegetation, animals, and surely, humans. This study is mainly directed towards hot deserts (covered with sand or rocks). To be even more specific, we have focused on the middle east and North Africa. The targeted area has an expanding population as well as an extended amount of deserts. The following maps show the global temperature and vegetation levels in order to help locate the project.
18
Chapter I Temperature Humidity Precipitation
Hyper-arid
Vegetation
Color coding from the most to the less abundant
Arid
Semi-arid
Temperature Humidity
Dry sub-humid
Precipitation Vegetation
Diagram showing desert climate categories 19
Water Scarcity
World map temperature levels
Data edited from: Google Earth Engine
World map Vegetation levels 20
Chapter I
Water in deserted areas is hard to contain. It is easily evaporated or lost due to low soil absorption capacity, and to high temperatures.
Water loss as evaporation Cool dry
A lot of cities, comparable to the ones in Egypt, Iran or Jordan are broadly losing water. Lakes and other big water bodies that serve the cities around them are drying, or even, dried already. This loss of water and drought is affecting cities in numerous scales (as presented in the diagram below).
Maximum soil absoption Water loss as run off
Hot dry
Moderate rainy
Meteorological Related to lack of precipitation and rain seasons
Agricultural Related to insufficiency of soil water for agriculture Hydrological Related to surface and sub-surface water (lakes, rivers, underground water levels etc.) Socioeconomic Related to physical water storage and affecting the populations
Drought
Different ways to define drought
21
Water Scarcity
Bakhtegan Lake, Iran Drying between 1984 and 2016 22
Chapter I
Toshka Lakes, Egypt Man made lakes in the 80’s Water reduced by 50% by 2006 Lakes completely dry today https://developers.google.com/earth-engine/datasets/ 23
Water Scarcity
Increase in water scarcity by 2050
Water scarcity is, therefore, an actual growing issue, and so, building to capture and control water consumption and to adapt to the cities, and the complexities in the generic deserts scenarios is essential.
150% 50%
Kuwait
Quatar
Iran
Lebanon 24
Jordan
Morocco
UAE
Egypt
Israel
Chapter I
Water scarcity to absolute scarcity 350%
300%
200%
Libya Gaza
Saudi A.
Tunisia
Algeria
Iraq
Syria 25
Yemen
Oman
Water Scarcity
I b. Water Scarcity and Urbanization Many reasons lead to city expansion in dry areas and deserts. Among others, job opportunities, industry, mining, tourism, refugees, etc. contribute to urbanization and sometimes overpopulation. Semi-arid areas population density is expected to grow from 1.5 billion people in 2010 to more than 2.0 billion in 2050, whereas dry sub-humid from approximately 0.8 to 1.2 billion in the same timeline. This rapid growth and massive construction, and abusive use of cities lands and resources are affecting water availability. Urban areas are warmer and wind circulation is less fluid.
The following diagram shows the different elements contributing to heat effects inside the city. The elements outlined are mainly construction material, factories, cars and traffic, and human activity.
Roofs Level
Lower Temperatures - Warm Air Urban edges City center
Lower Temperature Green parks
Construction materials - Increased thermal admission - Increased water proofing - Limited volume / Large heat capacity - Impermeable surfaces without vegetation prevent evaporative cooling 26
Canyon Geometry - Reduces wind speed - Reduces Sky view - Increases surface area and reflection
Wind speed variation
Chapter I
1994
2014
2030 Mega cities
4000
Large cities Medium cities
2000
Population (million)
3000 Cities of 500 000 to 1M Smaller urban areas
1000
Population growth in cities between 1994 and 2030 27
Water Scarcity
5% of the world’s population lives only in North Africa and the Middle East. 60% of this population is concentrated in urban areas. This region is, therefore, the main target for the project. The relation between water scarcity, city expansion, and
desertification is what makes it an essential intervention. The following images present the obvious expansion of urban settlements in some cities.
1984
2000
2016
Yazd, Iran
Muscat, Omman
28
Chapter I
1984
2000
2016
Cairo, Egypt
Amman, Jordan
https://developers.google.com/earth-engine/datasets/ 29
Water Scarcity
I c. Fog-laden air - A potential solution for water scarcity Fog is a visible duster consisting of tiny water droplets or ice crystals suspended in the air. It can be considered as a cloud. Surrounding parameters can influence fog, such as water bodies, topography (mountains, plains, etc.), or wind conditions and turbulence. Unlike dew water that consists of changing the physical properties of water before it becomes a droplet (condensation), fog water is already liquid. A lot of cities, especially coastal cities like Dubai in the UAE, Muscat in Oman, or Tenerife in Spain hold “fog-laden air�. In fact, studies have been made along the year in such areas showing that the amount of water contained in the fog is higher than the amount of rainwater. Fog collection is associated with higher wind speeds and lower solar radiation conditions. How can this form of water help us solve the water scarcity issue in the Middle East and North Africa? And how can we adapt to climate change and high urbanization and water demand based on a new approach for water harvesting? In order to carry on, the project considers the potential of learning from nature as well as architecture to allow the cities to perform.
30
Chapter I
Fog in Oman
Fog in Dubai
Fog in Egypt
31
32
Surving Water Scarcity
33
Surviving Water Scarcity
II a. Learning from nature Water is in the atmosphere. Plants and animals harvest this water in the driest environments. cacti and other succulent plants have sophisticated mechanisms to retain water and use it for long periods of time. These plants can control the amount of water released by extracting CO2 at night and storing it for photosynthesis during the day. This allows them to avoid releasing water vapor while opening their stomata cells for CO2 absorption. Moreover, their root system can go deep into the soil to maximize water absorption during wet seasons. These succulent plants often have little “hair� or spines allowing them to trap humidity from transpiration and to avoid evaporation due to wind movement. A section of these plants reveals a moist soft interior and a hard membrane (Stem or leave) that prevents water evaporation from the plant. Succulent plants transfer water from the leaves into the reservoirs where water will be stored and used during dry seasons.
Porous materials are water permeable and contain water into their anatomy. Other organisms such as natural sea sponges are considered as living filters. They continually suck huge amounts of water and throw it out directly stealing the nutrient from it. Although these organisms live inside the water (an environment with practically opposite specifications to the site of the research), it is engaging to study their porosity and the way water is handled inside. Plants and living organisms are fascinating to understand in order to start developing a system. In fact, advanced tools and research make it possible to create projects which evolve according to principles similar to those found in nature.
Some plants growing in the water (example red sea) have interior microscopic mechanisms allowing water to circulate inside the organism. These plants take the nutrients from the water and throw it back out. The anatomy of these peristomal structures is very complex and inspiring. Big pores allow the big flows of water and smaller ones to optimize this transmission.
34
Chapter II
No or little branching system and leaves - reduce sun exposed area Spines and hair - Reduce wind - prevent evaporation trap humidity from transpiration - create moisture layer Light (or white) color - Reduce heat absorption
Wax skin - sun protection and healing Stomata - Gas exchange and water management Opens at night and closes in times of extreme dessicance and heat
Root system - sends hormonal signal when soil is too dry
Inside Moisture - Water storage
Physical configuration of cacti 35
Surviving Water Scarcity
Tiny hair Curling - Minimize sunlight exposure
Suculent leaf or stem
Water in suculent leaf
Low water pressure High conductance / Flow Water reservoirs being filled - Thick surface to avoid evaporation High water pressure
High leaf water potential
Wet season
Low leaf water potential
Dry season
Leaf water potential: Capacity of cells to retain water Suculent plants’ mechanism
36
Chapter II
Numerous animals manage to survive in water-scarce zones and use their bodies’ physical properties to harvest the amount of water needed to survive. For instance, the Namib desert beetle displays an “amphiphilic” skin. The later has both hydrophilic and hydrophobic qualities (it repels and attracts water at the same time). The animal’s body has bumps, the tips of the bumps are like magnets for water while the sides of the bumps are waxier. The water collected from the fog aggregates on the tops and then falls right through the mouth of the beetle and allows it to drink. Another example is the lizard’s desert that is able to collect fog and due water onto its spikes or its eyes and then direct it towards its mouth to drink.
Those animals, persisting in extreme conditions, are the main inspiration for biomimicry serving water collection issues and trying to solve the water insufficiency in the designated areas.
Namib beetle standing on its head to collect the fog from the flow 37
Surviving Water Scarcity
II b. Enhancing accessibility to natural resources - Human Intervention A large amount of projects has been dealing with water, whether in a performative or a conceptual way. In fact, although being commonly perceived as a threat to architecture and material, water has been part of architecture throughout history. A first example of the symbiosis between water and architecture is the Basilica Cistern, Istanbul, that revisits the common idea of a cistern and a building and places them in the same box. Water is now part of the construction and one does not push the other away. It is an unconventional project in history combining, without barriers, the elements of construction and the water. Venice is also a familiar example, sometimes taken for granted. The city of art is completely performing on the water. Unlike the typical city division, Venice introduces a configuration where people adapt to their unlikely environment. Buildings and houses morphology host another way of transportation, circulation, living in the community, etc. Water, in this case, reshaped the individuals’ lifestyle. It is, on an urban scale, a different perception of dealing with water. The latter is no longer considered the enemy of architecture. Reconsidering water inside of architecture has also been clear in history within hot deserted cities. For instance, the Iranian courtyards have been introducing water bodies in order to keep a cool environment inside the houses and have a more comfortable space. More performative plans are created on very different scales. Wet facades are shown in NL Architect’s WOS8. The graphic representation of the Netherland’s wet weather is clear in the architecture. The architect did not try to hide nor remove moisture. On the contrary, it is celebrated and has the potential to transform the building depending on the rain intensity. “The architectural interior is constantly inundated with invidious forms of water.” Gissen, D. (2009). 38
This project performs in the glorification of water and its ability to transform a space or a perception of space. Water performs in Tadao Ando’s Architecture. The Water Temple is a perfect example of the capacity of water to transform the attitude and feeling of a person while entering a building. The illusion of going into the water and having direct contact between the latter and the architecture makes the user feel submerged. The liquid massive amount of water surrounding is a calming mechanism allowing a complete disconnection from the outer world and the entering of a new space. The glorification of water and its impact on architecture is also expressed through other kinds of art such as photography. Leonardo Benevolo, in “History of Modern Architecture”, shows another pattern of water’s intrusion into architecture. He points out the omnipresence of this element in our everyday lives. Pictures indeed usually show undamaged and clean images of what we try to promote. Therefore, Benevolo wants to give beauty and sense to natural elements covering our cities, and specifically water. In pictures of the Bauhaus or the streets of New York City after the rain, he intensifies puddles and water all over the floor and facade. Although the latter elements are considered to be a downside inside the city, Benevolo is expressing a contradictory beauty and an enhancement of flaws. Finally, the Super Galaxy, NYC Tropospheric Structure by Jason Johnson and Nathalie Gattegno attributes the philosophical meaning of water to a building. Puddles are no more shame to architecture, they do not represent mediocre buildings or unhealthy construction. Rather they are part of the experience and are infiltrated inside.
Chapter II
Basilica Cistern, Istanbul, Turkey
Tadao Ando’s Water Temple
Venice, Italy
Leonardo Benevolo Photography
Tabatabaei House, Iran Photo by Mostafa Meraji
Johnson and Nathalie Gattegno ‘s Super Galaxy, NYC Tropospheric Structure by Jason
NL Architect’s WOS8. 39
Surviving Water Scarcity
“Material transgresses boundaries, should become part of the design approach in order to avert potential disasters.� Gissen, D. (2009).
40
Chapter II
Photo by Samara Doole 41
Surviving Water Scarcity
When there is not enough rain, Chileans catch water in nets� The economist for The feisty fog-catchers of Chile, 2018 Water in its liquid form is sometimes scarce, in this case, letting it in is not an easy option but catching it makes more sense. This is what Chileans did in the harsh but foggy deserts of Chile. Some installations in drylands are using the material structure in order to trap water droplets from the mist - for drinking and agriculture - these structures are using basic nets and letting water drip by gravity into the tanks. The amount collected (about 3000 to 4000 L/day) is not very wide but it is considered a big step through water harvesting in dry areas. As mentioned before, fog collection does not imply a change in the physical properties of water. The droplets, already available in the mist, will be lead by the wind and hit the obstacle (the net). Water collection is then easy and efficient. In order to better use this mechanism, it is important to understand wind behavior and turbulence. The first step is to look at the vernacular architecture of Egypt, Iran, and other cities and civilizations that built to survive extreme temperatures. Getting inspired by these masterpieces, we can start manipulating the wind direction and speed and simulate it computationally for a better design of the project.
42
Chapter II
Fog Catchers, Chile 43
Surviving Water Scarcity
As briefly mentioned preliminarily, other parameters are useful for the fog catching process. The most important being the wind, it is interesting to consider previous vernacular architecture which is able to control wind behavior for users comfort. Courtyards are the urban porosity that creates wind circulation and air cooling inside dense areas. The morphology of this traditional architecture (especially in Iranian cities) is allowing wind to always be in motion. The water inside the courtyard is then a way to keep the atmosphere cool during the daytime. Shading and material choice are as well as important parameters. Actually, Egyptian architect Hassan Fathi uses material and construction systems in order to resolve drylands and deserts issues and make life more suitable. Material is absorbing, retaining and using water. But also keeping a cool environment to reduce water evaporation and enhance its storage. This project shows the use of primitive material, Mud. the architect is using local resources to solve local issues. The thick layer of mud absorbs the desert’s heat and natural ventilation allows the air to always move to create a cooler interior.
Hassan Fathi mud architecture, Egypt
44
Chapter II
Courtyard Masjed-e Agha Bozorg, Tehran, Iran
Wind circulation
Humidity Circulation - Cooling especially during day time How to deal with stagnant water v.s How to keep water for long periods of time 45
Surviving Water Scarcity
Title - Subtitle
Photo by Jason Leung 46
Chapter II
If parched Coquimbo is to catch more people, it will need more fog-catchers The economist for The feisty fog-catchers of Chile, 2018
47
48
Hydro Morphology System
49
Hydro Morphology System
III a.Redefining the traditional courtyard Considering wind as a crucial outer parameter that enhances the process of fog catching, the geometry, and shape of the “fog catcher” have to depend on it. The first step is understanding that a dense city would not allow the transmission of wind and that adding strategic porosity to the urbanized area will result in more fluid and rapid circulation. Therefore, the process starts by redefining the courtyard. Porosities were applied to the building and CFD simulations provided a better understanding and optimization. The following diagrams show the very early judgment and morphology of a building. It is going from a simple block to a more dissected element. The building allows more free spaces for the wind to circulate and also narrow spaces for more turbulence.
The wind simulation is utilized on multiple geometries; the courtyard is being redefined and accustomed to actual concerns. Its role is no longer to allow a comfortable interior for the house or building, but rather to create a better environment for the wind to circulate and therefore for the fog to be caught. As expressed in the diagrams that follow, wind simulations allow us to find which is the best geometry to take into consideration. The “courtyards” with the most turbulence and wind speed points are the ones selected for the building design. Among these courtyards, the most effective one (presenting multiple points of interest is the base geometry for our “fog catcher” building.
The second step is to analyze and investigate the potential behavior of the wind in real conditions. For this purpose, we have chosen a city of interest (in this case Cairo, Egypt). A potential site for the building is introduced in the city. Following the wind direction, and velocity magnitude analysis around the year, it is now possible to simulate it introducing the parameters obtained. The wind rose represents the velocity (m/s) with the color code indicated in the diagram. And it is clear that the dominant wind direction, in this case, is North and North East.
50
Chapter III
“Buildings become less envasive and closer to functioning as adaptable organisms” Baumgartner+Uriu (B+U) for “Animated Apertures” Housing Tower 2013
Diagrams of early judgment and morphology of a building 51
Hydro Morphology System
Wind rose Example chosen: Cairo Egypt North wind dominance Velocity values 0 to 12 m/s
Potential site in the city for the “Fog catching� building
52
Chapter III
Velocity magnitude m/s 18 16 14 12 10 08 06 04 02 00
Points of interest
Applying different geometries to design the “courtyard� and choosing the best ones according to wind simulation 53
Hydro Morphology System
III b. Designing the “Fog Catching� Building A bitmap image derives from the wind simulation on the chosen geometry. This representation goes from white to black the more there is turbulence and speed. The black areas are therefore of interest and are enhanced in the design. These are the parts where the facade system will be larger and have the most impact and the best outcome. We now simply extract the points of the darker area and chose the height of the facade at each point depending on the need and the availability. After the building is designed and is optimized to be the most performative for wind controlling, it will be ready to welcome the fog catchers. The latter element will perform the most important part of the system; to harvest water for buildings inside urbanized desert cities.
Geometry chosen
Wind simulation (CFD)
Bitmap image 54
Chapter III
Defining the facade’s height on each point of interest 55
Hydro Morphology System
Designing the building according to the points of interest 56
Chapter III
Designed building Potential future structure Potential future fog catchers attached to the building
Designing the building host for future application 57
Hydro Morphology System
Wind simulation is also applied to the final draft to evaluate how this building and its materials behave in the chosen conditions. It is therefore inserted in different environments. Among others, the city environment is the most relevant and therefore the only one demonstrated here.
58
Chapter III
Velocity magnitude m/s 18 16 14 12 10 08 06 04 02 00 59
Introducing the building in a theoretical environment and applying the CFD simulation
Hydro Morphology System
III c. Performative urban materiality: Porous concrete - Current applications Porous concrete (also called pervious concrete) is a combination of gravel, cement, and water. It is simply concrete without the sand aggregate. This material is most commonly used in urban areas on sidewalks or pavements. It allows water to pass through and can support the weight and forces of cars and other vehicles without being destroyed. During rainy seasons, water goes through the pavement and is collected for trees or other uses inside the city. It is at the same time a smart way to use water and an ideal solution for avoiding slippery and wet roads as well as water flooding. Porous concrete presents different qualities that are interesting for this project (considering the climate specification as well as the aim). Unlike normal concrete, porous concrete does not allow water to freeze inside in freezing weather (for example very low desertic temperatures) due to its ability to absorb more heat. Porous concrete is cooler than normal concrete, it also makes the air around it cooler.
As a hypothesis; porous concrete is used as a net. Each gravel would be assimilated to a nod and the pores inside of it would allow the air to pass through as well as the water droplets to settle before they reach the canals and later the tanks.
Porous concrete used on pavement
Being deeply inspired by the fog catchers, the project focuses on solutions to recreate this mechanism using more structural elements than the nets. It is as well trying to collect a larger amount of water in order to serve a larger amount of people and infrastructures. Based on this research, how can porous concrete, along with the building form and system perform as a fog catcher?
Warm middle layer - Avoid freezing water Cooler temperature around the concrete tile 60
Chapter III
III d. Performative urban materiality: Porous concrete - Experimental approache The process of mixing the concrete is very simple, it simply requires an understanding of the consistency. The porous concrete should not be very wet (shouldn’t make your gloves very dirty after grabbing it, and should not be glossy). It should neither be very dry. Pervious concrete is ideally a mix of one part cement and two parts gravel, but this combination is naturally adjustable depending on one’s personal needs.
One part cement - Two parts gravel
Too moist
Too dry
61
Good mix
Hydro Morphology System
Considering concrete is an affordable and accessible material, at the beginning of the project, many experiments were realized in order to understand which concrete would be the most adequate. In order to obtain better results with the limited supplies available, it was useful to build an environmental chamber. This allows simulating approximately the same measure of humidity potentially present on the allocated sites. A humidifier allows the simulation of the fog, and an adjustable fan enables the simulation of a more or less windy environment.
Environmental chamber Material Humidifier Hole for wind input
The percentage of humidity in the box is measured with the Arduino humidity sensor. This way it is possible to check the humidity before fog release, during the experiment and after it ends. The following summary shows some values noted during the experiments.
Temperature at start
25C
Temperature at end
26C
Humidity at start
35%
Humidity at end
80%
Water drying time
10 minutes
Some result of fog exposure for 55 minutes of the porous concrete flat tile Water in humidifier at start: 80 mL Water in humidifier at end: 70 mL 62
Chapter III
The amount of water collected after 55 minutes of fog exposure made it easy to decide on porous concrete. The following pictures show the amount of fog water collected on the plate for different materials used and exposed for the same amount of time in the box. After obtaining these results, the experiments focused on porous concrete begin. This is where the shapes of the fog catchers (Pervious concrete tiles) become more specific. The porous concrete tile is now the element we are mainly working on. It will be an additional component of the Hydro Morphology system, added on the building. The idea, for now, is to create a performative facade system. The latter will potentially, with the help of the wind parameter, be able to catch the fog. The shape of the tile will depend on its ability to capture more water as well as on its ability to let the wind circulate correctly and fluidly within itself.
63
Hydro Morphology System
No material
Normal concrete Predefined pores
Normal concrete Predefined pores + Pores
64
Porous concrete
Chapter III
Wet extremities
Wet Tile
Porous concrete - Before and after fog exposure
Textures porous concrete - Before and after fog exposure
As noticed in the pictures above, the flat tile is only wet on its extremities, whereas the textured tile is all wet after the same time of fog exposure. Unter the same circumstances, but with the difference of wind impact, the tile has an even better result concerning water absorption. The water is not only caught on the side exposed to the fog but it reached the backside of the tile.
Water reaches the back of the tile Textures porous concrete - Before and after fog and wind exposure
Wind
Water droplet 65
Attaches to pores
Hydro Morphology System
III e. Designing the porous concrete Tile The first geometries were simply made by computational trial. They are based on the experiment result that a more textured tile will attract more water. The “environmental chamber� experimentation has therefore stopped for a while allowing for the shapes to be created. The following tests are some textured surfaces obtained by creating points of interest on a flat surface and later applying hills and valleys to optimize the surface performance. These points are firstly imagined to capture the water that would be drained by the valleys (as represented in the diagrams). It did not take long to realize that the amount ant form of water trapped is not adequate for this kind of drainage. It is more optimal and effective to have the same behavior of water on the whole tile. The latter will, therefore, be able to attract water from all its parts. Consequently, all the points on the tile are considered points of interest.
Points of interest Potential direction of the water Very early geometries aiming to direct the water onto certain points of the concrete tile
Water flowing on concrete to the point of interest insite the valleys of the shape 66
Chapter III
Application of textured geometries on flat surface Computational experiementations
67
Hydro Morphology System
68
Chapter III
Plants peristome structure Teuchopora peristome (underwater plant) Photo: P. L. Cook & P. E. Bock.
The peristome is an anatomical feature that surrounds an opening to an organ or structure. It allows Free water circulation inside the structure with an exterior layer protecting from damage. Some plants use their peristomal structure in order to let water into their organism and absorb the nutrients needed. It is clear that this project hasn’t ceized to be inspired by nature. It redefines the peristomes as pores or porosity inside the concrete tiles and tries to find a way to let water in. The outside shell of the concrete, similar to the shell of the peristomes shown in the above pictures, protects the tile from being damaged. Porous concrete is indeed a material that reacts well with water and prevents any harm due to constant exposure to fog or humidity. It will be, surely, important in the next step to focus on the way the tiles are applied to keep the water from being stuck inside.
69
Hydro Morphology System
“There is something to discover within, and that something is often wet.� Search and Christian Muller for Villa Vals, Switzerland, 2009
70
Chapter III
Amman, Jordan 71
Hydro Morphology System
After noticing the importance of a homogeneous surface (allowing the same importance to each point/pore of the porous concrete available), another way of designing was applied. The tiles are now simpler and, in accordance with the latest geometries, they present a set of variations in their texture. Nevertheless, these geometries are maximizing the wind circulation as well as the exchange surface. The following examples show how a certain direction can shape the hills and valleys of each tile in order to have a multitude of forms, serving the same purpose, but in different positions.
Direct the tile shape using guide lines 72
Chapter III
Wind simulation applied on designed tiles
For this phase of the project, the tiles were constructed using wooden molds. They are designed on computer, and wind simulation is applied to the design. Later, the design is milled on wooden or
foam material and the porous concrete is poured inside of the molds. Milling is a great technique for creating such shapes and it allows the fast making of assorted molds. However, milling does have some inconvenience.
Milling wooden molds for the tiles 73
Header
Title - Subtitle
Cement and gravel
Some foam molds
Some wooden molds
Mold detail 74
Chapter
In fact, CNC milling (3 axis) does not allow negative shapes and limits the process of designing. For these reasons, in the second step of the project - further developed later - (The expansion at the Autodesk Technology Center), the project aims to create more complex molds for concrete (Starting with 3D printing methods). These molds will allow a more complex design and a bigger exchange surface between concrete and fog. Tile on display wall - Section view
Wooden piece to make the angle
Concrete mix
75
Hydro Morphology System
In order to create a display wall that shows one of many dispositions of the tiles, wooden and foam molds were made to cast the concrete. Some tiles were simply flat and made out of flat cut wooden pieces. While others were computationally generated and therefore had to be done with the CNC milling machine (as seen on the foam molds).
Some of the wooden molds were made adaptable to a certain angle in order to simply hang on the wooden piece behind it. This detail had to thick enough to support the whole weight of the tile, entirely made of concrete. The angle was calculated on the computer and simply applied with wood pieces as shown below. It is now manageable to put the tiles for display and change their location independently.
Angle for display (wood) Milled wall side (Foam) Hardware Mold wall (wood)
76
Chapter III
Usual concrete
Porous concrete & Usual concrete tile
Back detail for hanging the tile
20 cm
Concrete tile
Void for wooden wall
Displayed fabricated concrete tiles 77
Hydro Morphology System
III f. Designing the porous concrete Tile - Build Space Residency extension The Autodesk Build Space Technology Center is an opportunity to develop a part of Hydro Morphology in a different background. It is a center that welcomes multiple teams of researchers and students. The Build Space has valuable facilities making the research process more interesting and allowing projects to go further. After participating in the appropriate training, the residents are allowed to use the machine they need for their project; such as ABB robots, 3D printer machines, laser cutting machines, water jet machines, CNC milling machines, etc. For this phase of the project, during the two months of residency, the mold design for pouring concrete is the main target. The aim is to create molds that make the water absorption process more efficient. For that, the idea is to optimize the contact area between fog and tile by adding channels inside of the tile creating a way for the fog to circulate. The tile is now performative, not only on its surface but also inside. The images opposite show the first iterations of the concrete mold. They express the idea of large channelling systems inside the formwork. It is also clear that the mold is made out of a lattice, noncontinuous surface. This kind of structure allows the performance of the tile to persist even though the mold might be “trapped� inside of it. Indeed, the water droplets can still access the concrete regardless of the mold. Porous concrete being thick enough and having relatively big gravels will be poured perfectly without leaking from the mold.
First mold design 78
Chapter III
Different texture of the porous mold Porous concrete pooring Pores in the mold to optimize exchange surface Latice concrete mold Different texture of the porous mold Section views
The diagrams above show a section of the formwork with different surfaces. They explain how the concrete and the mold are organized on the inside of the tile. The channels are empty and the water, fog, and wind can circulate freely inside the tile while it performs systematically.
Working on the mold is interesting and shows different challenges, the first part focuses on the ability to have easy and effective geometries to produce. The process is done by dismantling the piece into little fragments and envision each part alone.
Different patterns are created to 3D print. The aim is to be able to print with the lowest amount of supports, to have the most effective circulation of water, and to print a reasonable scale for each purpose (visualization, exterior and interior coating, and actual use) of the mold. On the following images (next page) the first print is explained, the next ones will follow. The different copies show the printing tests. Some of them failed because of the small details and others because of the complex geometries requiring more supports for extrusion. 79
Hydro Morphology System
Complete formwork
Portion of formwork
Portion of a channel to 3D print
Portion of a channel - to print- divided i two peaces for a bigger, more detailed print 80
Chapter III
First 3D printing test, without supports 81
Hydro Morphology System
Part 1 - Smaller holes
Water movement Part 2 - Bogger holes : Better performance of the concrete, Facilitate intrusion of water droplets through the mold Comparing two prints of the same parts Porosity differences
82
Chapter III
Those pictures show different channels inside one tile. They are dismantled and printed separately for a better visualization process. Different iterations of the concrete tile are possible. The sections below show, the outside shell constituting the usual tile (previously designed), and in red the channels allowing the increase of the fog catching method.
Portions of the channels to 3D print 83
Hydro Morphology System
Wind Circulation
Empty channels allowing water and wind circulation inside the tile
Porous concrete Concrete mold
Sections of the formwork constituting one concrete tile 84
Chapter III
Sections of the formwork constituting one concrete tile 85
Hydro Morphology System
Not only is the design of the tile as a concept essential, but also the application of the design. To begin with, it is easier to simplify the process and fabricate a smaller concrete tile with only one channel. Later the porous concrete would be poured and the channel will create the wanted void in the tile. The first method presumed for this process is to create 3D printed channels, and cast thin foldable metal sheets in those channels. Finally, the metal sheets will take the form of the void predefined and will be fixed on wood formwork for the concrete. For now, there is no texture on the metal sheet, it is, therefore, removable from the concrete once it cures. This will surely allow the concrete to be performative since there will be no obstruction between it and the ambient foggy air. Flexible metal sheet
Compressing metal sheet on the 3D printed mold
Creating molds for metal sheets 86
Chapter III
Other ways are developed to cast the concrete and try to compare the best method for tiles and prototypes. Multiple materials can be used such as PLA (3D printed channel) and wood (for the mold sides). This way, it will be possible to test whether the concrete can be cast inside 3D printed molds and still be removed from the mold afterward (enable multiple uses of the same mold). Additionally, the channel can be placed in different positions for testing in the concrete tile. A sectioned tile is developed by milling half of a channel and pouring concrete onto the wood. This way, it will be easy to visualize the path of the channel and its effect on the porous concrete.
Wood box and metal channel
Concrete block Interior void
87
Hydro Morphology System
3D Printed channel Wooden mold walls
Concrete pouring
Porous concrete Wooden mold
88
Chapter III
1
2
Some wooden molds 1 - 3D printed channel + Wood walls 2 - Half a tile
Concrete tile - Visualization of a section 89
Hydro Morphology System
90
Chapter III
Testing the channels on porous concrete tiles 91
Hydro Morphology System
III g. Multi-scalar design strategy - channeling and hydro-mobility After focusing on the surface of the system created and the tile’s ability to capture water from fog, the project points on the channeling system allowing hydro mobility. Indeed, caught water droplets have to be carried into the building’s tanks in order to serve it. The previous pictures show a diagrammatic idea of these channels. The blue color represents the water’s trajectory. So how can this water potentially be lead into the building? An amphiphilic/phobic molecule or protein has both hydrophilic and hydrophobic components. In other terms, it attracts and repels water on different parts of its structure. In this project, the term amphiphilic/ phobic has been accustomed to the wires enabling hydro-mobility. The succeeding diagram explains how each wire, with different properties in its exterior and interior layers, behaves differently with water. Admittedly, as soon as the water droplet reached the pore of the pervious concrete, it is absorbed by the hydrophilic character of the wire. This process has to be done before the evaporation of the droplet. During it’s trajectory to the tank, the droplet is constantly repulsed by the hydrophobic shell towards the inner coating of the wire. Interior hydrophylic caracter Exterior hydrophobic caracter
Wire diagram 92
Chapter III
This section of the project is less developed than the rest. It requires a deep understanding of the physical properties of the material. Therefore, it is based on a theoretical approach and on concepts that might potentially be applied. A lot of studies are focused on hydrophilic wiring systems to transport and capture water. For example, Youhua Jiang, Shaan Savarirayan, Yuehan Yao, and Kyoo-Chul Park1 (2019). Fog collection on a super hydrophilic wire is a study focusing on fog water collection. In this research, the importance of hydro mobility is the main issue. It highlights the importance of the fog collection process and the under exploitation of the event of water movement on multiple wires after its collection. Superhydrophilic wires are used to calculate as exactly as possible the amount of water captured. The cables are therefore efficient and do not allow (or allow very little) water loss. This image shows the process of capturing the water and document as precisely as possible.
93
Hydro Morphology System
III h. Water collection and future use The section is a diagram of the different parts of the building. In fact, the system divides itself into multiple segments. The first layer is the facade system. The tiles are covering the shell of the building and are fixed with a metallic structure. This way, the weight of the concrete is not enhanced with a heavy structure behind it. Wires allowing hydro mobility are situated behind the tiles and in front of the building. They are protected from the sun and heat to minimize the evaporation of water being transported. The tubes lead to the next layer; the water tanks. The latter are divided between the floors. In order to minimize the distance traveled by the water, and therefore its evaporation. Each tree to four floors could potentially have its designated water tank. Situated under the floor slab, the container is shielded from the warmth. The distance between the facade and the interior glass allows a constant circulation of the wind. This way, the wind is always cooler and the humid air is constantly in motion, it is not trapped inside the concrete tile. The collected water will be used for different purposes serving the building and its inhabitants. It is mostly used for gray water; needing fewer filtration processes than drinking water. Inhabitants will be able to use gathered fog water for toilets, laundry, kitchen use, shower, gardening and landscaping, etc. This will allow the preservation of water and will lower the amount of water used by traditional suppliers. Similarly to cacti and succulent plants, the building will be able to store the amount of water needed during wet seasons for future drier periods.
Tiles - Capture Water
Wires - Hydro Mobility
Water Tank - Water Harvest
Metallic Structure
Glass
94
Chapter III
4.00 m
0.60 m
3.40 m
Constant air circulation
95
Photo by Brad Helmink 96
Conclusion
97
Hydro Morphology subsequently targets water scarcity issues in congested areas of the world. It is essential to work towards growing issues and actual problems affecting our populations and our cities. Middle Eastern and North African cities are unquestionably growing over the years. Their population is likely to keep growing despite desertification and lack of water resources. This project is an initiative to allow the growth of these cities in a more satisfactory direction concerning water harvesting and preservation. By focussing on the right climate in the target locations, it allows recreating a city’s morphology to match its specific needs. This process can be adapted to any matter concerning environments, urban planning, and life quality in cities. Based on the concepts of fog catching and water-retaining, the project finds a potential solution for populations and buildings allowing the use of gray water harvested from the atmosphere. To this end, new building morphologies have been developed in order to control natural elements such as wind. The wind is the first parameter allowing water droplets from the atmosphere to follow a certain trajectory and hit the obstacle - the fog catchers. In this case, the fog catcher is a pervious concrete tile. This tile does not need any additional structural elements to stand by itself. Nevertheless, it needs a metallic structure to be attached to the building’s facade.
Another interesting method (not developed in this research) would most likely be to adapt to existing cities and create an extension to the existing structure and dynamic. This approach might be a more adequate way depending on the resources and investments. After investigating the porous concrete capacity to capture water from a foggy environment, the tiles were designed in different ways to obtain: more exchange surfaces with the air, a bigger capacity of fog catching, better wind circulation, and wind turbulence. It would be important to investigate further the capacity of concrete to catch the droplets without absorbing any amount of water. This will depend on the mixing properties of the concrete and the materials that can be added to it to enhance certain properties. Some additives such as polymer dispersion powder can allow the concrete to be water repellent and more resistant. This is usually used in construction to have better durability of concrete with time. With additives, one can, therefore, prevent water loss inside the concrete tile. The trajectory of the water continues through the tile to amphiphilic wires allowing hydro-mobility. A droplet will continue its way to the building. The capacity if these circuits to contain a considerable amount of water, to drain it as quickly as possible to the reservoir and to be sustained over time is still questionable. Although the idea is to create a multi characteristic wire being water repellent and water attractor at the same time, the exact material that should be used needs a lot more investigation and laboratory facilities. Some researches have been focusing on polymers to attract water from the environment.
Using this method, the project necessitates the construction of new buildings and the rethinking of the city plan. If a certain city would conceivably use the concrete fog catchers to sustain its water reservoirs, it will need to change the entire way it grows.
98
Conclusion
Working on Hydro Morphology was not simply a design procedure, but also a way to understand that having an idea is a positive start. Some projects don’t always arrive at the wanted purpose, but it is important to realize that any result obtained is a step towards the solution. In my case, a simple drop of water captured from the atmosphere is the start of a bigger process. Architecture is, therefore, the tool we use to solve real problems. Furthermore, the Autodesk technology center allowed this project to have a more detailed design approach. It was the opportunity to develop a better understanding and analyzing the concrete tile with more freedom and autonomy. The BuildSpace permits the residents to be comfortable with the tools they are using and to have a stable idea of the materials and technologies that could possibly be used for fabrication.
Finally, this project opens up a lot of possibilities concerning water harvesting in desert cities. Further research is always welcome to expand the knowledge about porous concrete properties and wiring system for mobility. It emphasizes the link between biological phenomena, culture, resources, urbanization, and Architecture. Hydro Morphology is an interdisciplinary project, it is a small part of a whole system investigating ways and techniques to use construction materials and building elements for performative purposes.
Photo by Hugo Kruip 99
Photo by Vijetha Surakanti 100
References
101
GreenBuilt, (2015). Why are most of the cities, located near water bodies, more economically prosperous than ones that are landlocked?. [online] Available at: https://www.quora.com/Why-are-most-of-the-cities-located-near-water-bodiesmore-economically-prosperous-than-ones-that-are-landlocked/answer/Daniel-Moreno-21 [22 January. 2015] Pressbooks, THE ROLE OF WATER FOR SUSTAINABLE URBAN PLANNING. [online] Available at: https://isscbookofblogs. pressbooks.com/chapter/the-role-of-water-for-sustainable-urban-development/ Cambridge Dictionary, Edition. Cambridge. Available at https://dictionary.cambridge.org/dictionary/english/desert) United Nations, (2010). United Nations Decade for deserts and fight against desertification. [online] Available at: http:// www.un.org/en/events/desertification_decade/whynow.shtml. Netherlands Environmental Assessment Agency, (2017). Population growth in drylands. [online] Available at http://www. un.org/en/events/desertification_decade/whynow.shtml [31 July. 2017]. BBC. Hot deserts. [online] Available at https://www.bbc.com/bitesize/guides/zpnq6fr/revision/4 Cairo vision 2050. The Strategic Urban Development Plan of Greater Cairo Region The Guardian, (2018). “Cairo has started to become ugly”’: why Egypt is building a new capital city. [online] Available at https://www.theguardian.com/cities/2018/may/08/cairo-why-egypt-build-new-capital-city-desert [8 May. 2018] Kenneth M. Elovitz. (1999).UNDERSTANDING WHAT HUMIDITY DOES AND WHY. The USA.American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. Gissen, D. (2009). Subnature. The USA. Princeton Architectural Press. 799. Biology discussion. Xerophytes: Categories and Physiological Adaptation of Xerophytes | Plant Adaptation. [online] Available at http://www.biologydiscussion.com/plant-adaptation/xerophytes-categories-and-physiological-adaptation-of-xerophytes-plant-adaptation/15271 Mesohydroxero. Ecological Niche of Xerophytes. [online] Available at https://mesohydroxero.weebly.com/xerophytes. html# Encyclopedia Britannica. Population And Community Development And Structure. [online] Available at https://www. britannica.com/science/desert/Population-and-community-development-and-structure Encyclopedia Britannica. Population And Community Development And Structure. [online] Available at
102
References
https://www.britannica.com/science/desert/Population-and-community-development-and-structure Matthew J. (2001).HYDRAULIC CONDUCTIVITY, XYLEM CAVITATION, AND WATER POTENTIAL FOR SUCCULENT LEAVES OF AGAVE DESERT AND AGAVE TEQUILANA. The USA.The University of Chicago. Amer J. (2000). Linking Hydraulic Conductivity to Anatomy in Plants that Vary in Specific Root Length. The USA. Björn B., Kevin J. TILBROOK & Andrew N. OSTROVSKY. (2013).What, if anything, is a lyrula? Upper Austrian State Museum, Geoscience Collections, Austria. Museum of Tropical Queensland, Australia. Department of Palaeontology, Faculty of Earth Sciences, Geography and Astronomy, Geozentrum, University of Vienna, Austria. Department of Invertebrate Zoology, Faculty of Biology, St. Petersburg State University, Russia. P. L. Cook & P. E. Bock. EXECHONELLA (EXECHONELLIDAE: BRYOZOA, CHEILOSTOMATA) FROM THE RECENT AND MIOCENE OF SOUTHERN AUSTRALIA. Honorary Associate, Marine Biology Section, Museum of Victoria, Australia. School of Ecology and Environment, Deakin University, Melbourne. Shape of Life. Sponges: Filter Feeding Made Visible. [online] Available at: https://www.shapeoflife.org/video/sponges-filter-feeding-made-visible Bustler. (2013). B+U’s Animated Apertures to be featured at the ArchiLab 2013 exhibition. [online] Available at: http:// bustler.net/news/3011/b-u-s-animated-apertures-to-be-featured-at-the-archilab-2013-exhibition [August 30. 2013] Laurent P., Jérémy B., Romain M., Thibaud P. (2018). The Atmospheric Boundary Layer Over Urban-Like Terrain: Influence of the Plan Density on Roughness Sublayer Dynamics. IAUC Teaching Resources. The Urban Canopy Layer Heat Island Fatemeh B., Norhati I., Dahlia M. (2015). Design Characteristics and Adaptive Role of the Traditional Courtyard Houses in the Moderate Climate of Iran. Tehran, Iran. Faculty of Architecture, Planning, and Surveying. Research Management Institute Hashim, R. (2014).Effect of Peat on Physicomechanical Properties of Cemented Brick. The Scientific World Journal. Green prophet, (2010). Hassan Fathy is the Middle East’s father of sustainable architecture. [online] Available at https:// www.greenprophet.com/2010/02/hassn-fathy-sustainable-architecture/ [February 26. 2010] BBC, (2015). Trapping humidity out of fog in Chile. [online] Available at https://www.bbc.com/news/world-latin-america-32515558 [17 May. 2015]
103
John T. Kevern, Vernon R. Schaefer, and Kejin Wang (2009). Temperature Behavior of a Pervious Concrete System. Transportation Research Board Jasper Overduin (2016). FAÇADE FOR WIND AND STACK DRIVEN VENTILATION IN TROPICAL HIGH-RISE OFFICE Cover. Montevideo, Uruguay Tri Mulyono and Anisah (2018). Properties of pervious concrete with various types and sizes of aggregate. The State University of Jakarta, Jakarta, Indonesia. Youhua Jiang, Shaan Savarirayan, Yuehan Yao, and Kyoo-Chul Park (2019).Fog collection on a super hydrophilic wire. Northwestern University, Evanston, Illinois. Xikui Wang, Jia Zeng, Xinquan Yu, and Youfa Zhang (2019).Superamphiphobic coatings with polymer wrapped particles: enhancing water harvesting. Article in Journal of Materials Chemistry. Southeast University, China.
104
References
105
Yasmina El Helou - Institute for Advanced Architecture of Catalunya - 2019