RESEARCH

PRECEDENT PROJECTS

Precedent gathering coincided with the prototyping of joinery techniques from the beginning. Sources were gathered both locally and abroad in order to better understand contemporary trends in bamboo construction. Precedents are grouped into four different categories: traditional lashing, metal joinery, concrete embedded joints, and 3D printed joints.

CORD LASHING

Son La Restaurant, VTM Architects Son La, Vietnam | 2014

Due to its remote location, local bamboo and stonework became the source material for this project. Once treated with mud and smoke, bamboo culms were roped together to express verticallity with a dense grouping of members at the ends to increase shear resistance. Beams-to-column and some beam-to-beam connections are made using the Mark II lashing. Further unidentified techniques are utilized for additional support.

Bamboo Pavilion, Penda Beijing, China | 2015

This modular system is designed only with bamboo and lashing cord. The culms are not pierced, leaving them unharmed for future use after installation. It is not fixed on the ground to facilitate disassembly and promote sustainability. The system is capable of infinitely expanding both vertically and horizontally, and the architects hope that it can be a resource for temporary housing in the instance of a natural disaster.

METAL JOINERY

Bamboo Gateway, West Line Studio Chishui, Zunyi, Guizhou, China | 2008

Bamboo is utilized as a vertical shading device in this project. Steam-treated bamboo poles were fastened together end-to-end with a bolt in order to reach the desired height by the designers. Metal joints were also used to attach the bamboo cladding system back to the building.

Bamboo Structure, Pouya Khazaeli Parsa Ramsar, Iran | 2009

Starting as a student project, this structure is comprised of bamboo poles arrayed in a circular form. Conventional gas pipe t-connections were used without a fixed assembly at the base of the structure. For a team of three people, the shelter could be constructed from start to finish in no more than two days. This system allows for future disassembly and possible displacement by simply disconnecting the bamboo from the gas pipes.

CONCRETE EMBEDDED JOINT

La Ceiba Dining Hall, Lucila Aguilar Arquitectos Chiapas, Mexico | 2016

La Ceiba Complex consists of housing, dining rooms, and workshop pavilions. Through their use of bamboo, the architects desired to “transmit a message in the region that industrial constructions can have another, more natural language.” In the dining space, bamboo central columns are comprised of sixteen culms that are embedded directly into a concrete base with no additional components.

Kontum Indochine Cafe, VTN Architects Kontum, Vietnam | 2013

This project combines many techniques of bamboo construction to create a very large open space. Steel tension rings are inserted into bamboo columns to add stiffness before they are embedded within the concrete foundation. The shape of the columns was inspired by the Vietnamese fishing basket, which has a wide opening that narrows towards the other end. In total, there are fifteen columns supporting the roof, giving inhabitants the feeling of being within a bamboo forest.

3-D PRINT JOINERY

Bamboo Pavilion, Bezalel Academy Jerusalem, Israel | 2017

3-D printed joints solved the question of flexibility in this pavilion. The designers created a unique joint for the splicing of bamboo poles and vertical and horizontal member joints. The 3-D printed components were designed to allow for a specific pole radius while simulating traditional lashing techniques.

Digital Bamboo Pavilion, ETH Zurich Zurich, Switzerland | 2019

The pavilion utilized 3-D printing in both its cladding and joints. The member connections were printed in stainless steel guided by a digital optimization process. Shading panels were fabricated with 3-D printed recyclable UV resistant thermoplastic over Lycra textile, giving it stability and flexibility.

Cord Lashing

Cord lashing is the oldest bamboo construction technique, and it continues to be utilized in the twenty-first century. The cord used in the lashings can be made from natural fibers or synthetic materials, such as rubber. Wax coatings are also common, as they add extra friction to the knots. Despite its long history, cord lashing comes with many limitations. Compared with other joinery techniques, it is much less durable. Additionally, this method is heavily dependent on the physical characteristics of each bamboo culm. For example, it is recommended to make joints near the nodes of the bamboo; this can be difficult to do at large scales because of bamboo’s inherent irregularity. On the other hand, the accessibility of this technique, in terms of affordability and construction, as well as its temporal qualities make it very successful when used in installations and smaller projects. Because the culms are not being damaged, they can easily be reused in future projects.

Metal Fasteners

Metal joinery is a newer trend to emerge in the bamboo construction industry, but it quickly gained widespread popularity due to its reliability. Where traditional cord lashing is dependent on the location of nodes, metal fasteners may be installed anywhere along the length of a culm. Fasteners do the job of adding an artificial strength to the bamboo that is impossible with lashing cord. Additionally, the use of a prefabricated metal joint means that construction times are drastically diminished. Workers that are trained in steel and timber construction are already knowledgeable in traditional fasteners, making it easier to find skilled labor; because traditional lashing requires more training, the use of metal makes more sense from a financial standpoint. Despite metals contributions to the bamboo construction industry, it does present some drawbacks. Culms that are pierced by fasteners are less easily reused, meaning the generation of waste is a bit higher. Furthermore, the joints are not as aesthetically pleasing, making them less desirable to many architects and clients.

Concrete Embedded Joints

When maximum stability is desired, bamboo culms may be embedded within concrete footings or foundations in order to permanently unify the structural systems. While the seamless joint between the concrete and columns can be pleasing to the eye, this method requires more maintenance in order to retain stability. Because concrete absorbs lots of moisture, the bamboo is susceptible to rot. Once the culm decays, there is no way to restore it back to health without completely replacing it. This is not only difficult but costly. Reuse and recycling of these columns is also difficult due to the concrete that is infilled inside the polls. From an environmental standpoint, this is a less desirable option.

3D Printing

As digital technology and fabrication becomes more accessible, new possibilities emerge. The twentyfirst century’s answer to bamboo construction is the 3D printed joint. Using flexible mediums to allow for maximum tolerance, printed fasteners push the boundaries for mass customization and formal optimization. Many joints aim to mimic the pleasing aesthetic of traditional cord lashing, making them even more desirable for architects and clients. Depending on the project, they are capable of making both permanent and temporary connections between culms. Additionally, the bamboo may not be damaged by incision, making reuse very easy. However, due to the precision of the medium, matching diameters to unpredictable bamboo columns can be quite challenging.

NOTABLE ORGANIZATIONS

As we began researching potential guest lecturers, we discovered these three organizations, each possessing their own unique perspective on Bamboo. We maintained direct contact during development.

Better Bamboo Buildings is an online blog created during the Covid-19 pandemic by Ewe Jin Low. In order to continue educating people about bamboo during the lockdown, he established this communication hub that holds virtual courses and workshops.

IBUKU is a team of innovative designers that focuses on bamboo construction. Founded in Bali, Indonesia, by Elora Hardy, her team has built over sixty bamboo structures over the past ten years. They believe in the possibilities of sustainable architecture and hope to push the boundaries as they continue to expand in the new decade. Ewe Jin Low was a member of their team near the start of his bamboo journey.

Carole Meckes is the President of the Texas Bamboo Society and the founder of Bamboo Branch, an Austin-based bamboo grove. Through her life-long dedication to the material, she strives to aide in both the promotion and research of bamboo.

Bamboo U Carole Meckes

IBUKU

MATERIAL SOURCING

All of the bamboo that was used during the prototyping phase as well as the workshop kits was sourced from Bamboo Branch. The local bamboo grove is owned and operated by Carole Meckes, president of the Texas Bamboo Society. She and her husband purchased the property where Bamboo Branch is presently located back in the 1990s. She has been devoted to the material for most of her life.

The Materials Lab team was involved in every step of the bamboo cultivation process. Once the team arrived, we descended the steep slope of the property. First, we uprooted the most mature culms, which had a more tan finish compared to the younger, green bamboo. This could be achieved by either pulling the culm directly out of the ground or sawing the pole just above the roots. Once removed from the soil, we clipped off all of the branches that spanned the length of the bamboo. Next, all the culms were hauled up the hillside, where they were sorted based on diameter and cut to lengths of no more than twelve feet. Finally, they were placed in the truck and driven to campus.