Week 10: DURABILITY OF BAMBOO

A quick recap on characteristics of bamboo. Bamboo is a type of hollow grass native to many areas of the world. It is sometimes thought of as the poor man's building material because of its widespread cultivation and use in tropical climates where much of the world's poor live. Many of these cultures find use for bamboo as building material.

Advantages

Bamboo is considered to be sustainable and renewable alternative to hardwoods, foremost because it regenerates at exceptionally fast rates. Some bamboo species have been known to grown more than several feet per day. A bamboo forest may be harvest every 6 years while hardwood require decades between harvests.

Disadvantages

Bamboo does not contain cross fibers and is consequently, not designed to bear weight width-wise, with the exception of the points at the nodes. Bamboo is prone to splitting, especially when standard construction fasteners, such as bolts, screws and nails are inserted. Special fastening techniques are required when joining pieces of bamboo.

Based on the previous post, having the research question;

How can a combination of Kaccha and Pukka styles can be used to increase bambo's characteristic thus improve its durability and feasibility of the building?

To simplify the research question, the research will be regarding the type of material used, having a natural material and a common construction structural material to increase the bamboo's durability; functioning as a structural material or building construction material to sustain live load and dead load of the building.

New Research Question:

How can a composite of natural and structural material increase the durability of Vernacular Architecture in the modern industrialize constructions?

Modern connections have been proposed by Huybers, Shoei Yoh and Renzo Piano. These connections solve the issues of complex geometries by joining the members in various ways. These connections require puncture of the bamboo walls sine all fibers in a bamboo culm run parallel once a bolt is placed through it and the connection loaded in tension, the bolt acts like a wedge and splits the bamboo. Also the puncture allows moisture to enter the culm and accelerate decay.

More recent systems have been engineered to make joinery stronger and less labor intensive. The joint of preference has developed by Simon Velez where he uses a bolted connection with an understanding the bolt alone concentrate much on the wall of the bamboo. Therefore, the point where every bolt penetrates each bamboo culm, the void between the solid internal nodes is filled with solidifying mortar. Members of a truss come together at angles and tension forces are anticipated, a steel strap is placed to bridge the pieces. It is important to design with redundant system that is capable of both compression and tension.

What is compression? What is tension?

Bamboo + Cement

The curing process of the cement will affect the structure of the bamboo due to lack of hydration. It absorbs moisture from the bamboo fiber, causing the bamboo to crack.

Using bamboo as structural material project by utilizing bolted with or without concrete mortar infill provide strength rigidly. This experiment does not require for shape deformation of bamboo; thus this frame truss system is certainly prevent bamboo from bending and buckling in the middle of the culm.

Larger holes were drilled into the bamboo to insert the mortar into the joint segments. The mortar was mixed with the optimal quantity of water; the bamboo pieces where then duck taped together ti maintain their positions as they were filled with mortar and left to sure for a week. Once mortar is cured, the tape can be removed.

Bamboo can be cut into different shapes to make 4 kinds of joints: corner, T, point and extension joint. Though holes were drilled into bamboo segment to insert re-bars. This re-bars will absorb most of the stress moments and allow the bamboo structure to sustain high stress impacts as occur during earthquakes.

Bamboo tends to shrink with time making the string joinery slack and insecure. Therefore the joinery system replies on bolts and mortar-fillings maintaining their shape over time.

Bolted Bamboo with Infilled Mortar + Reinforcement Steel Bar

 Bamboo filled with mortar are reinforced by an additional the rebar is embedded in mortar, the load is transferred evenly across the member's cross section and can transfer high acial loads to the bamboo.

The bamboo is cut at the end axially crosswise to generate a cone by tightening a steel clamp. The cone is filled up with mortar so that the cone is able to transfer its force to the outer high tensile fibers. The mortar cylinder transferred the forces to the screws.

Since bamboo is very strong when loaded axially, the new connection developed to resist only axial tension and compression forces and not increase resistance to bending. This is consistent with the loading of the truss in which the truss members experience axial loads and any bending is small and accidental. The new connection involves embedding a common steel reinforcing bar into mortar filled bamboo culm and fillet welding several of these members to a steel gusset plate. The innder surface of the bamboo is roughened to provide a bond between the mortar and the bamboo while avoiding puncturing the member. A common steel clamp is also placed at the end of the member to provide confinement of the bamboo and prevent splitting of the bamboo. Because the rebar is embedded in mortar, the load is transferred evenly across the member's cross section and can transfer high acial loads to the bamboo. Finally, the incorporation of the steel gusset plate makes the bamboo easy to connect in any configuration desired.

To construct this connection, steps required as follows:

1. cut the bamboo culm allowing the first node

2. punch out the first internal node to provide hollow section in the bamboo

3. removal of the node can be done easily with a hammer and a piece of rebar

4. provide positive connection between the mortar and the bamboo

5. inner surface of the bamboo will be roughened by constructing gouges

6. splace at 6mm are made for the first 3-5 diameters of the bamboo using a drill

7. compress sand, water and cement to form mortar and placed in the hollow ends of bamboo

8. rebar is embedded into the mortar and the side of the bamboo is tapped repeatedly to vibrate mortar to eliminate voids

9. steel clamp is then placed at the end of the bamboo and allowed to cure for 28 days

10. member can be welded to the gusset plate and the truss is erected

Experiment: To study the strength of specific bamboo joints and structural behaviors

While bamboo has been used for centuries, the traditional methods of lashing bamboo together are not appropriate for the design of long span trusses. These lashed connections also do not fully utilize the its strength; it solely rely on friction, transferring load between members is limited thus require more members to do the same job. Therefore joints in bamboo always has been difficult because it is hollow, has nodes and resists only a little shear stress. Many traditional joints suffer from weakness or deformation. Many joints cannot take advantage of the strength of the culm itself and a special problem is to design a joint for tensile forces.

The New Connection (to be continue)

Pecha-Kucha on Durability of Bamboo (slides will change automatically after 20 seconds)

BAMBOO CONSTRUCTION SEMINAR REVIEW

Here is a review after attending the seminar.
Pros

1. It was a knowledgeable and interesting seminar as I do not have any knowledge regarding bamboo construction. Now that I have attended the seminar, this magical and interesting vernacular material can be a new typology for our future development.

1. I was really impressed for having such a knowledgeable speakers for the session; coming from various country, introducing various ways of bamboo construction.

1. Hospitality of the seminar was great as well, having everything all well prepared from the starting of the session, during the break and until the end of the session

Suggestions

1. I was looking forward for the architectural design concept of the bamboo construction. But due to language barrier, I felt the translator did not explained much details on the conceptual design; how its being derived etc. He should have also explained more on the process of deriving the concept as well as difficulties faced during the construction phase or completing the project.

1. The purpose of the seminar is to promote bamboo construction, but I felt that participants should also get more information regarding the limitation of using the materials as well. I felt the seminar is too marketing oriented although people nowadays focus mainly on cost and profit. But people has to know the actual facts on the limitation of the material in order to improve it for further future developments.

1. If they have focused more on discussion regarding ways of bamboo construction, issues faced, etc.based on various countries rather than just promoting the end product of the bamboo, participants and also the speaker would have gotten more information from the discussions. (would prefer exchanging of knowledge rather than marketing the end product)

Week 9: BAMBOO CONSTRUCTION TECHNOLOGY

The scientific Vernacular explores the turning points when inputs of scientific knowledge boost the creative urges of architects for new forms of architectural expression which were traditionally concentrated in Vernacular Architecture; taking the leap from a stylist approach to knowledge based and innovative approach with the use of technological science.

This week, I will be discussing about several issues presented during the 1st Bamboo Construction Seminar Malaysia 2015 that was held on the 10th May in Corus Hotel, Jalan Ampang; how contemporary scientific knowledge has altered traditional bamboo constructional technology.

Bamboo is being knwon as the nature's green diamond because of its iconic material for green technology. It can be identified through colour and diameter. Thus it is known as the giant grass because it can grow anywhere.

Bamboo has many functions. It can be used as a construction material, using its root to get water, turn it into eateries such as cookies and flour, daily uses such as shampoo, body wash, fertilizer, food wrapper, clothes etc. Bamboo also produces more oxygen and take in as much carbon dioxide compared to other plants.

Therefore, bamboo itself has a lot of advantages. It is a cheap, fast growing material with excellent statistics according to the mechanical properties. The strongest period the bamboo will be in will be during its 3rd-6th year. Fertility of soil will also affect the growth period of the bamboo.

        Traditional Method                 Vacuum Treatment

On the other hand, bamboo has its disadvantages such as decaying, susceptible to insect and fungal attack. To overcome this issue, bamboos were being treated in several ways to increase its durability. Submerging the bamboo into the soil with water for 6 month will be one of the authentic treatment towards the bamboo. Another treatment can be done by adding boric acid into the water; submerging the bamboo into it for 2 weeks; the bamboo can be as long lasting as timber. Various ways such as using herbs, using a vacuum tank, using smoke etc. can also be used to treat the bamboo.

Have you heard of bamboo in winter? Due to its gradual change in temperature, it will not affect the bamboo. Several bamboo structures in China and Japan lasted more than a thousand years. It can widthstand the gradual change of temperature according to its seasons.

Bamboo can be used in various part of the building, from interior to exterior, from furnitures, floor to roof;

   
          Roof Shingles                  Floorings and Door

                                      Openable Roof Structure

                          

Bamboo has got a round profile therefore creating connections will be leading to difficult geometric structures at the knot. Various connections can be used; for example, friction tight rope connections, nuts and bolts connection, positive connections, interlocking connections,


Besides that, bamboo is hollow in the middle of the cane; therefore it can be reinforced by pouring concrete inside.

Since Bamboo itself has several issues, bringing threats towards the mission and vision of our future development, a combination of kachcha and pukka styles can be used to increase its characteristic thus improve durability and feasibility of the building. How? What is kachcha and pukka?

Kachcha is a building made of natural materials such as mud, grass, bamboo, thatch or sticks and is therefore a shott-lived structure; Whereas pakka is a structure made from materials resistant to wear as forms of stone or brick, clay tiles, maetal or other durable materials, such structures are expensive to construct as the materials are costly and more labor is required.

Research Question:
How can a combination of kachcha and pukka styles can be used to increase bamboo's characteristic thus improve its durability and feasibility of the building?

Week 8: PECHA KUCHA

Here is a video of a Pecha Kucha regarding the Solidification of Sand Dunes and Parametric Architecture that forms a Vertical City.
* slides will automatically change after 20 seconds

Week 7: THE VERTICAL 'DOWNWARDS' PARAMETRIC CITY

Sand Dunes + Parametric + Vertical Architecture

Recap from the previous post; an enjoying model making session to identify spaces, light and shadow quality; as well as the quality of air for natural ventilation.
In what way can this project be classified as a Parametric Architecture? How to transform it into a vertical city? Can this vertical city be a habitable space for living organisms?
To start off, the first question will be what is parametric? Parametric (based on architecture) is relating to a process (parameters/algorithmic); often obtained through using various tools or data; translating the process together with the tools stated as parameters (algorithmic) and forms a unique style called Parametricism.

The parameters; known as algorithmic will be used between design intent and design response to achieve vertical architecture. Design element that will be used between design intent and design response will be based on the solidified sand dunes. As a recap of the process of making solidified sand dunes; tiny sand particles going through the harnessing of microbial activity by inducing carbonate precipitation to solidify the sand; turning it into a large sandstone.

Parametric Architecture happens at the process before inducing carbonate precipitation into the sand dune, making it to transform from a tiny sand particles into a huge solid structural sandstone; because habitable space will be created through injecting giant balloons into the dunes. Excessive sands that will be removed, transforming into a habitable space; can be removed either by hand or wind; turning it into an underground architecture.
Underground architecture has several important features that cannot be overlooked in order to create habitable spaces. These features will also be part of the several parameters to create Parametricism Architecture. This includes:

Creating an underground river filled wells for daily usage

Creating staircase between transition of levels

Creating a large shaft; likely used as the primary well for residents underground and on the ground surface and stone doors in each level

Protecting the underground city from surface threats. All of these features have to done before the inducing of carbonate precipitation because sand particles are still their small, light and weak properties.

As mentioned from the previous post, Edward Glaeser argues that 'cities cannot build out but build up instead based on capitalist doctrines of hyper-density'. Besides that, the height of the sand dunes varies; thus the issue of hyper-density will not be able to be resolved. Therefore, merging of medium rise together with underground architecture will be the best solution for hyper-density in the dessert.

A case study on the largest ancient underground city in Turkey's Cappadocia region; will be used as a reference towards the solidified sand dunes. This remarkable underground city called Derinkuyu house 20,000 people in 18 stories of living quarters, shops and escape routes. It is one of the jewels of Turkish archaeological wonderland. The underground tunnel initially has a passage of 7km. It was then only planned and analyzed when the underground city was discovered.

Derinkuyu was being dugged over 250 feet below Earth's surface and boasts numerous tunnels, halls, meeting rooms, wells and passage ways. Inside the underground ecosystem, it can sustain thousands of people, replete with air shafts and water channels. Locals likely retreated to its depths, experts suspect, whenever armies or invaders approached during those turbulent times, and waited out the danger like a turtle in its shell.
There are 36 other underground cities in the Cappadocia region. There were safe places where Christians spread the new faith secretly and to worship freely away from persecution.

First and second floors house the missionary school, baptism pool, kitchen, food depots, bed rooms, dining rooms, wine cellars and stables.
Third and fourth floor will the hiding places, tunnels as well as depots for weapons. When the town is being attacked, people will escape through these tunnels.
Millstone doors are used between tunnels to prevent an attack into the tunnels; could block from the inside with these millstone and people would descend to their shelters. These millstone doors could not be opened from the inside, acting like a fire door.
Derinkuyu has 52 air shafts (70-85 meters depth) being dug downwards towards the water table. This is where the availability of fresh air takes place; being segregated to all floors.

The large area reserved for storage in such a limited area appears to indicate the need to support a large population underground. The mystery of who built it and why remains. The region of Cappadocia is well known around the world for its underground cities; the above ground is equally impressive.

The landscape is peppered with ancient volcanic stone chimneys, known as 'fairy chimneys'.

Based on the above case study of the underground city's habitable spaces, it can be applied in the solidified sand dune architecture. The parameters (algorithm) to create such parametric will be as follows:

SAND DUNES + PARAMETRIC + VERTICAL ARCHITECTURE 

provides a solution to desertification in the Sahara desert; vulnerability in an attempt to de-polarize the natural and built environment by incorporating the sand dunes - weaving together intensive human development and resilient desert ecologies.

Maximize Nature's Lifeguard
Make use of the issue of desertification; sand dunes, transform dune fields into a solid permanent structure that will be able to promote environmentally responsible development. Dunes can be stabilized by plant structures, help to mitigate storm and create habitat for the living organism in the desert.

Provide Resilient Energy Sources
Capturing the kinetic energy of winds from the connected habitable spaces, bringing natural ventilation throughout the underground city.

Create Integrated Architecture
Integrating architecture into the dune field anchors both the social and ecological functions of  Sand Dunes. A scalloped architectural shall protects the local community from the desertification, integrates commercial activity into the dune and provides a foundation for sand accumulation.

Week 6: MODEL MAKING

The Continuous Porous Skin and Body

Recap from the previous post; I was explaining regarding the process of solidification of sand dunes; as well as the ways of constructing the solidification process. As for this week, a model will be made to identify parametric architecture from the solidification process.

A Tafoni-liked form and structure being used to create the model; making use of the solid structure to create habitable spaces within it. Using the internal structure of sand dunes; where the grain of sand piled high form microscopic chains and networks in such a way that they carry most of the pressure from the weight of the material abound them.

Spaces inside the sand dunes represent a habitable spaces inside the dune for living organism (eg. human and animals). Though having a rough texture at the surrounding spaces; but having a space that is shaded away from sun shine and rain; having the space being natural ventilated; making occupants inside the space to immerse themselves in a huge rocky-fabric cocoon.

 

Elaborating the network of spaces downwards into the ground; using openings at the entrance as windows to allow natural daylight into the dunes. Due to the uneven surfaces and nonlinear networking down into the tunnel; reducing the amount of daylight into the spaces inside. Therefore, reflective devices can be used to increase daylight into the habitable spaces.

Openings of the entrance of the dunes leading towards the spaces underground forms a parametric capsule that can be repeated within the surface of the capsule or elaborating down in the ground to cater for the hyper-density of urban desert. Spaces below can be used as a hiding spots as well as serving as communication and supply routes and living quarters for residences.

Back then, tunnel systems were of great important to their resistance against their enemy.