Bamboo
I. Introduction
Bamboo
Bamboo is a very versatile material that can be used in many of the same industries and applications as wood (which bamboo commonly can substitute for). It can be made into a fabric for clothes and other accessories, fuel, furniture, paper products such as paper towels and toilet paper, utensils and tableware, and certain varieties are used as a food ingredient or medicine. In the built environment it can be used for scaffolding, bridges, and even buildings, with new concepts for multilevel buildings being designed. This variety of uses dates back as far as 7,000 years ago in China, where they used it for food, clothing, housing, etc.
Common Perceptions
I believe bamboo is commonly perceived for narrow uses, and that most people don’t grasp the wide variety of uses bamboo has. Many people view it used in Asian cuisine (bamboo shoots, panda diets) and a decorative garden plant (ie. bamboo walls)
My perception of bamboo before included some of the infrastructural purposes of bamboo, and its quick, renewable growth. As I researched bamboo more, I became aware of its use in textiles, and the theoretical use of it in high-rise buildings in the distant future. I think this background research of bamboo gives me a slightly different perception of bamboo than others, as I believe that bamboo is a versatile, highly renewable material product, while others may be limited in their knowledge of bamboo and its uses and environmental impact.
Burning Questions
What are the possibilities of bamboo replacing wood and other support materials in taller infrastructure (ie. is a bamboo skyscraper a tangible possibility)? Due to bamboo’s fast growth rate, is it a better renewable resource than trees? Are there any common material uses that bamboo as of now isn’t used for, but could someday in the future? What steps need to be taken in societal attitudes and policy-making for bamboo to be more prevalent in our daily material consumption?
II. Origins
Cellulose: Cellulose is the most abundant organic chemical on earth, and is a sugar-based polymer that serves as a structural component of the plant cell wall. Cellulose molecules are randomly oriented and tend to become packed together (Rowell 2005, 35). Along with hemicellulose and lignin, cellulose forms 90% of bamboo’s total mass (Mayowa 2018).
Hemicellulose: Hemicellulose is also a polysaccharide (composed of sugar molecules) polymer (Rowell 2005, 37). They are also crucial to the structural integrity of the plant cell wall and are prevalent throughout the plant cell wall and bamboo. One of the main differences between hemicellulose and cellulose is that hemicellulose has a lower degree of polymerization than cellulose, which is the number of glucose units in a cellulose or hemicellulose molecule (Rowell 2005, 38). The percentages of cellulose and hemicellulose vary in bamboo across species and by bamboo’s age, but are significantly more present than lignin (Mayowa 2018).
Lignin: Third major component of bamboo, and biomass in general. They are amorphous polymers of phenylpropane, and as such don’t have single repeating units like cellulose or hemicellulose, instead consisting of complex arrangements of phenolic units (Rowell 2005, 41). Chemical modification research has been done to remove lignin- among other components- to improve bamboo’s fiber tensile strength.
Timeline
7,000 years ago [China]: Bamboo used for basic tools such as chopsticks, and diet. One of the earliest examples of human uses of bamboo.
5,000 years ago [China]: Bamboo used to construct treehouses, one of first examples of bamboo as a building material.
256 BCE [China]: Duijang Dam and Irrigation System built in China. The levee portion of the dam made with woven bamboo filled with stone; one of the earliest examples of use in large scale, utility construction.
200 BCE-200 CE [China]: Bamboo used to create paper and books, early example of manipulating bamboo’s structural properties, a form of technology that will be used later in construction.
1300s [China]: Bamboo used as interior building material including bedding and flooring during the Ming dynasty. Marks one of the earliest examples of bamboo used in interior building, and another example of bamboo altered to address different needs rather than just building framework.
1486 [China]: Bamboo charcoal is created, a more sustainable and healthy alternative to traditional coal, made from pieces of the plant 5+ years old. Bamboo charcoal creates purer air and reduces pollutant residue.
1894 [England]: First bamboo bicycle patented and revealed in England. While not building related, demonstrates the use of bamboo outside of China on a worldwide scale, and shows the inclusion of patenting bamboo technology, which is more relevant in modern uses of bamboo.
1947 [Italy]: Gucci uses bamboo in handbags due to resource shortage from WWII, patent a method to heat and bend bamboo to retain its shape once cooled and fixed to the bag. This example of manipulating bamboo shape with heat is used in contemporary construction.
Late 1990s [China]: China develops treatment to make bamboo look and feel like hardwood by cutting and planing bamboo stalks into planks.
III. Context
As a building material, the main challenges bamboo faces are its flammability and issues with being an organic material. As a member of the grass family and an organic material, bamboo is fairly susceptible to fire. As such, building ordinances are hesitant against the use of bamboo in taller, multi-level construction projects. The preferred materials for high rise buildings- concrete, steel, and glass- are relatively fireproof, making them safer alternatives to bamboo. Additionally, as an organic material, bamboo is susceptible to deterioration from a variety of sources. These include deterioration from rain, moisture and sunlight, rot, fungus, cracking and shrinking if harvested too early, bug infestation, and twisting and tapering. However, with proper treatment and harvest time, bamboo can avoid many of these issues and last for over 50 years (Lo 2021). Treatments can be chemical or non chemical, and protect the bamboo from weathering, bugs, and fungus. As an organic material, bamboo is overall a very eco friendly material. However, chemical treatments like the heat and soak method (almost boiling then leaving to soak), are commonly used and highly effective, but result in high amounts of pollution due to harmful chemicals that are used that are poisonous or highly acidic (NBO 1961). Bamboo is also an ethical and accessible product. Many bamboo construction projects involve community engagement and create industry. As it grows rapidly and freely around the world, it is also a highly accessible material.
Bamboo thrives with construction projects due to its rapid growth, eco-friendly nature, and versatility. Bamboo matures in 3–5 years and can reach its full height in a single day (Lo 2021). Compared to wood, bamboo’s construction contemporary, bamboo can be grown and harvested much quicker than trees, which take about 50 years to harvest. A shorter harvest time means that bamboo requires less resources over its lifetime to grow, and takes up less area for growing than trees for lumber. During the growing stage, bamboo provides several benefits to the environment. As a plant undergoing photosynthesis, it sequesters carbon and outputs oxygen into the atmosphere. It also helps restore land and reduces erosion, which in turn prevents water runoff. Overall, bamboo has much lower energy costs related to product development and transportation in comparison to mainstream building materials such as concrete, brick or glass, which require high temperatures and transporting. Bamboo is generally sourced somewhat locally and doesn’t require as energy intensive methods to prepare it for construction. Lastly, bamboo is a versatile building material; depending on how it is prepared and manipulated, it can be used to make beams, mats, or curved beams and even prepared to resemble wood.
Many of the obstacles bamboo faces as a building material due to being an organic material can be overcome with proper practices in growing, harvesting, treating, and construction. While some obstacles don’t yet have implemented solutions, such as its flammability, the benefits of using it- rapid growth, environmental benefits, comparable or even superior performance to contemporaries, and versatility- make it a building material of high value and appropriateness.
IV. Case Studies
Case Study 1- Hybrid Bamboo+Wood Panels
RIZOME is a bamboo construction team that is developing prototypes for hybrid bamboo/wood mass timber that addresses fire hazard concerns while still comparing to the strength of steel and concrete (the hybrid panels withstand compression forces of 7,000–11,000 psi, compared to concrete’s 3,000–6,000 psi) and being significantly lighter, cheaper, and less harmful to the environment. RIZOME completes these hybrid Cross-Laminated Timber and Laminated Veneer Lumber panels by applying 1/8–1/4" thick panels of bamboo around the exterior of conventional or engineered lumber. They also apply a pressurized borate treatment; this combined with the product’s density gives it an ASTM-e84 Class A Fire rating- the highest rating, and much better than the Douglas Fir’s Class C rating. This gives it the fire safety, strength, and durability of products like steel and concrete while being lighter and cheaper, making it very competitive towards these highly common construction materials.
The bamboo veneer can also drastically increase the durability and strength of wood types that are generally perceived as soft or less strong, making it competitive towards products that are solely wood (RIZOME hybrid panels have an average Janka hardness level of 1600 lbs/ft, while Douglas fir ranks at 660 lbs/ft). Lastly, it also seeks to address the problem of pure bamboo materials, which are not extremely fire resistant; the hybrid material here is also stronger than bamboo alone and is much more fire resistant. However, due to being a composite material, it is unknown how feasible recyclability is for this product. While the material consists of two separate components (an interior wood panels, and an outer bamboo veneer), RIZOME makes no note of recyclability or life cycle of the material, and the adhesion of the two components and the additional borate treatment may affect the viability of recycling.
Case Study 2- BPC (Bamboo Plastic Composite)
Bamboo plastic composite (BPC) is another material that combines bamboo with another widely used material to address the challenges of bamboo. In this case, the challenge addressed for the most part is bamboo’s susceptibility to water and dampness. BPC is made by combining bamboo fibers with small plastic granules. The bamboo fibers act as the structural and reinforcing material, while the plastic resin is the matrix material. In some cases, plastics such as Polybutylene succinate can be used as the plastic resin for BPC, which is a biodegradable polymer. As such, BPC in this instance is biodegradable. In most applications, it is used for flooring or outside decking, but can also be used for furniture, pottery, etc. This replaces common materials such as pure wood or pure bamboo decks, which are susceptible to rot over time. It is also a more environmentally friendly alternative to pure plastic or rubber materials. The use of a biodegradable plastic like polybutylene succinate is crucial to ensure the product isn’t sent to a landfill at the end of its material lifecycle. However, the product seems unrecyclable, as the bamboo fibers and plastic granules are so closely intertwined and mixed that separating them to properly recycle both would be nearly impossible. As such, reuse or biodegradation are the only two courses of action besides landfill at the end of the material’s use.
V. Action
Activity 1- Diverse Uses of Bamboo
Objective: Learn more about the diverse range of products bamboo can be used for, that fall under a variety of industries. Explore uses beyond the standard uses of cuisine, construction, and furniture. By taking note of what you would normally expect a bamboo product to be made of, think more about bamboo can act as a substitute to many common and potentially harmful or inappropriate materials.
- Visit Bamboo Grove’s website.
- Spend a few minutes looking around on the site, and specifically find the pages “Bamboo Products” and “General Uses for Bamboo.” (Both can be found on the Home page, or by selecting from the drop down list from “About Bamboo” at the top of the site.)
- Find 3 examples of products made of bamboo that are not cuisine, construction, or furniture-related, and take note of the product, the industry it relates to, and what you may normally expect that product to be made of.
Takeaway: Hopefully, from this activity, you are able to become more versed in the diverse use of bamboo, and begin to see in what ways you may already be using bamboo and the wide array of materials that bamboo can replace.
Activity 2- Benefits of Bamboo and Bamboo in Design
Objective: Learn more about bamboo as a building materials and some of the properties of its composition that make it comparable or superior to its main contemporary, wood. Look at some models of bamboo homes and learn about similarities to contemporary homes via looking at price, design, size, etc.
- Visit Bamboo Living’s page on why bamboo is a good building material.
- Skim through the page and identify two reasons why bamboo can be a better building material than wood.
- Spend some time looking at the models, found in the “Models” tab at the top of the page. Find a model that you find particularly interesting, and take note of its name, square footage, pricing, and two similarities you notice to “traditional” wood housing.
Takeaway: From this activity, you will hopefully gain a better understanding of why bamboo is a good building material and why it can be comparable or even better than other commonly used materials like wood, steel, or concrete, that can have more harmful impacts on the environment, be more expensive, and heavier in the building’s construction. Secondly, I hope to elevate your understanding of bamboo infrastructure beyond the “traditional bamboo huts” and demonstrate that modern bamboo infrastructure, can have similar sizes, appearances, prices, and features as traditional homes.
VI. Analysis
In conclusion, I learned more about the versatile uses and applications of bamboo that are prevalent throughout a variety of industries. These can range to textiles in fashion industries, paper products in the office and households, furniture, construction, cuisine, accessories, instruments, bicycles, etc. The variety of uses of bamboo mean that it could be used to replace many common materials we are familiar with, the primary and most similar one being softwood and timber, especially in the construction and paper products industry. As a much more rapidly renewable material than trees, and with comparable or even higher levels of carbon sequestration, bamboo has a high appeal to replace wood, especially in single-use material uses like many paper products.
Bamboo is not only comparable in composition and performance to wood, but has similar or higher strengths level to materials such as concrete and steel, which are prevalent in the construction industry. However, bamboo is less harmful to the environment, cheaper and lighter in the construction project. That being said, bamboo does have some performance issues that make it a bit less appropriate in comparison to its contemporaries; the major of these is its flammability, susceptibility to rot, and susceptibility to insects and degradation. While concrete and steel have reached new heights of building, wood and bamboo have stayed at lower heights. Only more recently have we seen several-storied wooden structures like the Wood Hotel in Norway. However, treatment methods and hybrid composites address bamboo’s flammability concerns, and may open possibilities to taller construction with bamboo; or, at the very least, construction that incorporates bamboo to a certain extent, perhaps with concrete or another material for support and flame retardancy. These options make bamboo more appropriate as a 21st century building material as it increases the safety, which is one of the main concerns, while maintaining or increasing its performance. One drawback to these solutions as they make bamboo a less environmentally friendly material due to the emissions and use of materials such as plastics.
Bamboo is also an appropriate material because it frequently addresses welfare. Bamboo, especially in smaller scale projects, commonly is grown in small situations, often by local bamboo farmers. This also means that bamboo is often sourced locally, and requires fairly low transportation costs, maintaining its low environmental impacts. Many bamboo construction companies emphasize community empowerment and the stimulation of the local growers’ economy.
New design techniques, the versatility of bamboo in construction, and a cultural shift to “green” building has increased bamboo’s perceived value to many over the past few years. As more research is done to increase bamboo’s strength and fire resistance, it is likely to become a more prevalent material in the construction industry. Returning to my original questions from the beginning of the semester, I believe that bamboo is on its way to replacing wood in many scenarios, specifically taller infrastructure like skyscrapers. While research is already being conducted that improves bamboo’s safety concerns, I believe it will mostly be overturning outdated building codes that prohibit the use of bamboo in taller construction, once it becomes more widespread and accepted that modern bamboo technology has overcome this hurdle. While bamboo has the ability to replace materials such as wood, concrete, and steel, these materials aren’t inherently bad, and can be very useful if used in appropriate contexts. That being said, I see bamboo evolving in the future to continue being a highly appropriate, eco-friendly, and high-performing material in combination with these common materials we are familiar with to create new material technologies, designs, and architecture.
VII. References
Carter, Troy. “Bamboo Skyscrapers.” Medium, Rizome, 25 Mar. 2020, medium.com/rizome/bamboo-skyscrapers-eded5b234726.
Horvat, Alen. (2016). A study of the uncertainty associated with tar measurement and an investigation of tar evolution and composition during the air-blown fluidised bed gasification of torrefied and non-torrefied grassy biomass.
Lo, Ewe Jin. “Bamboo Two-Part Workshop Featuring Ewe Jin Lo.” Lecture presented by UT Austin School of Architecture Materials Lab, Austin, TX, March 2 and 4, 2021
Mayowa Akeem Azeez and Joshua Iseoluwa Orege (May 30th 2018). Bamboo, Its Chemical Modification and Products, Bamboo — Current and Future Prospects, Abdul Khalil H.P.S., IntechOpen, DOI: 10.5772/intechopen.76359.
National Building Organization (NBO), India. “PRESERVATIVE TREATMENT OF BAMBOO.” Ekistics 11, no. 68 (1961): 491–93. Accessed May 9, 2021. http://www.jstor.org/stable/43613525.
Oduro, K.A. & Obeng, Elizabeth & Abukari, Haruna & Pentsil, Sarah. (2020). Bamboo Policy Integration Analysis — Ghana.
Rowell, Roger M.; Pettersen, Roger; Han, James S.; Rowell, Jeffrey S.; Tshabalala, Mandla A. 2005. Cell wall chemistry. Handbook of wood chemistry and wood composites. Boca Raton, Fla. : CRC Press, 2005: pages 35–74.
“Bamboo Plastic Composite (BPC) Facility.” Bamboo Technology Park, www.bambootechnologypark.com/bamboo-plastic-composite-bpc-facility.
“Climate-Positive Bamboo Building.” RIZOME, www.rizomeco.com/.
