Can Grass Be Stronger than A Tree?

Abstract:

As population increases and global warming changes the environment, the strains on our atmosphere and land become obvious. Our forests and jungles are the largest consumer of CO2 we have and are in dangerous decline. Deforestation and jungle destruction not only reduces biodiversity and wildlife refuges, but also contributes to global warming. In order to preserve our forests, we need to find new ways to reduce our dependency on wood.

Since bamboo is one of the fastest growing grasses, a significant converter of CO2 and potentially as strong as wood – this project will test the strength of wood against bamboo. If bamboo can support even close to the same weight as wood, we can imagine a day when bamboo can be used as a replacement.

In an effort to make this experiment practical, within my appendix, I will also propose a way that we can grow bamboo in the Bay Area utilizing marginal/unused land. These areas will create revolutionary new carbon-offset zones, provide additional revenue to local governments, reduce significant amounts of CO2, develop new businesses in an emerging industry, and promote, by example, green living.

Purpose:
Is bamboo stronger than wood, and if so, can it help us stop global warming?

Research:

Hypothesis: The wood will break under the same conditions and weight before the bamboo.

Materials:

9 sticks of bamboo sized per test
9 pieces of solid wood sized per test
2 large plastic buckets
2 “S” hooks
Chain to attach the hooks to the wood
Sand and bricks
Two cement platforms to put the wood on

Procedures:

Lay the wood on the platforms and attach the “S” hook.
Attach a bucket to the “S” hook and fill with sand/bricks until the wood breaks.
Weight the bucket. Take the “S” hooks of the wood and place them on the bamboo. Attach the bucket to the “S” hooks and fill with sand/bricks until the bamboo breaks. Repeat three times per test.

Test Results Data

|Test Type |Length |Height |Width |Weight |Weight Held |
| | | | | | |
|Weight Test | | | | | |
| Bamboo | | | | | |
| Wood | | | | | |
| | | | | | |
| Bamboo | | | | | |
| Wood | | | | | |
| | | | | | |
| Bamboo | | | | | |
| Wood | | | | | |
| | | | | | |
| Average | | | | | |
| | | | | | |
|Dimensional Test | | | | | |
| Bamboo | | | | | |
| Wood | | | | | |
| | | | | | |
| Bamboo | | | | | |
| Wood | | | | | |
| | | | | | |
| Bamboo | | | | | |
| Wood | | | | | |
| | | | | | |
| Average | | | | | |
| | | | | | |
|Equivalency Test | | | | | |
| Bamboo | | | | | |
| Wood | | | | | |
| | | | | | |
| Bamboo | | | | | |
| Wood | | | | | |
| | | | | | |
| Bamboo | | | | | |
| Wood | | | | | |
| | | | | | |
| Average | | | | | |

Analysis

There are many ways to test the strength of materials. In this project, the test will look at the comparative strength of the two materials – bamboo and wood; specifically pine, on their longitude. Due to the differences in dimensions, bamboo is round and hollow where as wood is typically sold in square or rectangular dimensions as well as being solid, there needs to be some accommodation.

In the first test, rather than flatten the bamboo and potentially diminish its carrying capacity, this test will keep the length of the wood and bamboo consistent and vary the thinness of the wood in order to match the weight of the two materials. This will compare the relative strength of the bamboo to wood based on weight. In the results table this is referred to as the weight test.

In the second test, the length of the wood and bamboo will again be held consistent but rather than attempting to keep the weight the same; the test will keep the height and width of the two materials the same. This will give a considerable weight advantage to the wood material but will allow testing the strength of the two materials with the same dimensions. In the results table this is referred to as the dimensional test.

The third test will also be a dimensional equivalent test with the length, width and height held consistent but in this case the bamboo will be flattened so that it’s a dense material more similar to wood. The weight advantage will still go to the wood product but it is a mare fair comparison. In the results table this is referred to as the equivalency test.

To start the tests, three material samples of both wood and bamboo, for each of the tests were created. The materials were cut to size, weighed, measured and recorded. Due to the properties of the materials this took quite a bit of time to make as exact as possible in accordance with the demands of each test.

A platform was then made to hold the materials at each end and allow the bamboo and wood to span the length. An “S” hook was then placed in the middle of each material and weight attached until failure was noted. Each test was performed three times and then the average determined.

Conclusion:

The tests show conclusively that bamboo can be significantly stronger than wood. The fibers seem to be stronger than wood whether we keep the dimensions the same or significantly stronger compared to its weight. These test show that bamboo is ___ times stronger than wood when taking weight into account.

How can that be? I think there are several explanations. One is that the strength of wood and bamboo does not come from its inner core. In fact it looks like the strength comes from the outside wood or fiber and the center only really contributes weight, not strength. This can be seen in the weight test where the wood and bamboo weight were kept the same. The bamboo since it has a hollow core was able to be wider and taller than the wood. Its empty cylinder shape allowed almost all of the fibers to be used in absorbing the weight put on it. Of course this is also due to the test. If the bamboo and wood had been tested on its latitude (standing up) I suspect the wood would have supported more weight since the core is then being used something the bamboo does not have to help.

We also see though that the bamboo is stronger on the dimensional test and that suggests that the fibers themselves are just stronger than wood. This is confirmed by scientific tests using expensive machinery. In fact, certain bamboo has been shown to have the capacity to hold _____ 23,000 lbs compared to oak at 22,000 lbs. Amazing strength for a grass.

So why do we still use wood? I suspect you know the reasons as well as I do! First, this country is known for its large forests and so wood is or has been, plentiful. Its much more common than bamboo and for hundreds of years has been the product of choice for building, heating, energy and other uses. In comparison, the Asian countries use bamboo widely for many things we would typically associate with wood or even steel! Even today bamboo can be seen used in Hong Kong for scaffolding, in Thailand for fences, wind breaks, and natural walls and in China for furniture.

In addition, even though bamboo is stronger its hollow and so can’t be shaped as wood can. We can easily sand, cut and shape wood to be whatever size or shape we want. It’s very easy to join wood together as well with many types of strong joints since wood is solid. Bamboo’s strength is then its weakness. Its difficult to join two pieces of bamboo together and doing so can actually weaken in unlike wood where the joint is often the strongest part of the two pieces.

Appendix

After travelling throughout Thailand and watching shows on National Geografic about global warming, I think we can use bamboo to make a difference in our world. Most people only think of using bamboo as a replacement for wood but due to the issues above – its uses are limited. But what if bamboo’s main use was not for flooring and furniture but reducing our carbon footprint? Right now we plant trees for this, but bamboo actually absorbs and uses more CO2 and I think it can be planted in places that trees cannot.

In San Francisco, San Mateo and Santa Clara there are over 500 miles of freeways. Approximately every five to ten miles there is a cloverleaf which has areas of unused land of ~50-70 acres depending on the length and number of offramps. If we planted bamboo on both side of the soundwalls for these 500 miles along with planting culms of bamboo in the cloverleaf areas we can conservatively plant over 5,700 acres of bamboo which can with proper harvesting absorb 40 tons of CO2 per acre or 230,000 tons of CO2 per year!

Proposal: Allow companies to plant bamboo on either side of the soundproofing walls along the highways, as well as the land within cloverleafs or off-ramps. If done in just the Bay Area this would be a significant amount of the land that is currently not used for any reason. By allowing companies to lease this land, cities could then market them as carbon-offset areas. The value of these areas could be significant if a carbon tax is introduced. A carbon-offset in a densely populated area like the Bay Area is unheard of but provides significant benefit - it produces an offset where its needed for maximum benefit, demonstrates and provides examples for people of sustainable living every day and leverages mis/unused land.

I have emailed several experts in the area of bamboo on this topic and received positive feedback. Mr. DeBoer who has written many articles on bamboo and conservation, a book on its use and growth, as well as design techniques gave me some great ideas and potential concerns which I have tried to address below. He also put me in touch with Mr. Nik ____ at Urban Bio Filters who has actually already done something very similar in Oakland already. Their emails are attached.

Potential Issues:

Land - Available by lease from the local cities providing needed tax revenues, which increase in value over time since value of the land grows with the age of the bamboo.

Management of the Bamboo - Leasing the land to companies fixes this problem. Companies will want maximum growth for maximum CO2 uptake and will harvest as appropriate. Harvesting maximizes carbon sequestration and can provide additional revenue for the company in addition to the revenue by selling the cabon-offset credits.

Leaf Cleanup - Currently community service people clean the highways but it could be a requirement of the leasing company to put up netting or gather the green waste. Since these will be “managed forests” there should be less work by the city, as companies will keep the land in order.

Bamboo Market - While the bamboo market is not huge and it would take three years for this bamboo to become harvestable, marketing the land as a carbon offset allows the cities not to depend on the commercial value of bamboo but the combination of both values to make the land profitable. As the bamboo matures the land becomes more valuable due to the value of the bamboo and that it maintains its carbon uptake consistently.

Irrigation – Bamboo needs water however it’s often used to clean waterways in Asian counties. By requiring companies to use recyled water it will allow cities to build out this infrastructure at little to no cost to the city. Since the land is not used today, the cities will potentially save money in maintenance and landscaping. If we directed storm drain water here it could also help reduce the storm runoff into the Bay as we saw just recently further greening the Bay Area.

Carbon Taxing - Some cities have explored carbon taxes. While not popular, this would increase the value of the land since it would be a certified carbon offset zone. In any case there is a market already for carbon credits, which makes this land valuable.

Non-Profit Cooperation - Bringing in non-profits dedicated to the environment and working with them to jump start planting is perhaps the best way to get this started. After three years with harvestable product, the markets should prefer this material rather than shipping bamboo from overseas. Being grown as part of a carbon offset, eliminating the need for shipping overseas as well as documented growing patterns (no strip farming/cutting, documented age since you can not tell 3yr old bamboo easily) this bamboo should be given a premium in the market.

Bamboo Control – Some people think that bamboo spreads uncontrollably. This is simply not true. Although some bamboo can spread by its roots, many species do not and remain well within their boundaries. Since the land being used in this case is surrounded by concrete the bamboo can not spread anyways but the city could require non-invasive bamboo species just in case.

Additional Land / Revenue – In Thailand, the pillars supporting offramps and the overhead subway are all covered in planters. If we did this there could be substantial additional area made available to start bamboo plants. I have not estimated the amount of additional space but as you can see from the picture and knowledge of our freeways – it could easily double the space!

Calculations:

50 acres x 100 cloverleafs = 5,000 acres
3 ft wide per soundwall side x four sides x 500 miles = 727 acres 5,727 acres x 40 tons of CO2/yr = 230,000 tons of CO2/yr absorbe

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http://seattletimes.nwsource.com/html/pacificnw/2004360712_pacificpbamboo20.html