用沙袋或土袋建造牆壁的概念至少已有 100 年的歷史。[1]最初和現代，這些往往是粗麻布（粗麻布）織物袋，形成臨時結構，用作防洪屏障或軍事防禦工事。目前尚不清楚第一次這樣做的確切時間，[2]但有一些證據表明，在第一次世界大戰之前，在軍事環境中使用沙袋牆。確實，一些用油浸麻袋加固的第一次世界大戰戰壕仍然存在，儘管打算是暫時的。[2]
使用土袋建造永久性結構（例如房屋）是最近的發展。[1] Otto Frei 於 1960 年代在德國嘗試建造土袋。[3] 1970 年代，同樣在德國，卡塞爾理工學院實驗建築研究實驗室的 Gernot Minke 和其他人正在研究不用水泥建造抗震結構的方法。他們使用填充有浮石的聚酯和粗麻布管來製造圓頂結構。1978 年，危地馬拉的弗朗西斯科·馬羅金大學和中美洲研究中心 (CEMAT) 在危地馬拉建造了一個結構，用石灰浸泡過的棉布袋裝滿浮石砂。[4]
Earthbag 建造方法由波斯建築師 Nader Khalili 推廣，他最終開發了一種他稱為Superadobe的建築技術，其中填充有濕潤土坯土的聚丙烯袋或管被用於形成通常為圓頂結構的結構。哈利利繼續出版了 6 本書，並於 1981 年創立了非營利組織加州地球研究所（California Institute of Earth Architecture）。[5]他因聲稱他的超級土坯技術“免費為人類和人類服務而受到批評”。 1991 年，他試圖以非常籠統的術語為土袋建築技術申請專利。據稱，他要求所有其他土袋建築的發起人與他簽訂合同以繼續他們的工作。[1]
項目
術語
Contained earth is the basic technique of filling containers with earth. Modular contained earth is the use of bags or tubes in walls which rely on rebar and/or strands of barbed wire between courses to keep the form of the wall. Flexible form rammed earth is another term that has been used.[3] Solid contained earth is a more accurate term for hyperadobe, developed by Fernando Pacheco of EcoOca in Brazil. A pliable knit raschel mesh tube is used, the same material used in packaging fruit. This mesh allows the earthen fill to solidify between courses as long as the fill is built damp. Solid contained earth has higher shear and out of plane strength than modular contained earth of the same soil, and may allow the use of wire mesh in addition to or in place of barbed wire.
Contained Sand uses sand fill or any fill too dry or with poor cohesion that performs structurally like sand bags. Such bags must be solid-weave fabric have good protection from fabric damage. Contained sand needs more vertical reinforcement than contained earth. Structurally, alternative loose fills (like rice hulls) will create a wall more similar to contained sand than to contained earth.
Contained Gravel uses fill of any aggregate larger than coarse sand. Contained gravel can function as concurrent footing and footing drain material, and can use either solid-weave or mesh containment.
Containers
The basic vessel for contained earth building may be either numerous bags/sacks which are used as individual bricks, or long tubes which become the entire course in a wall. A common size for individual bags is 18 inches by 30 inches when empty (45*76 cm).[2] The fabric used in bags or tubes may be a solid weave or a mesh.
Polypropylene
Polypropylene (also termed polypropene) is the second most commonly produced plastic in the world. Long rolls of polypropylene tubing are available from manufacturers. These large rolls of tubing are normally intended to be cut and stitched into individual bags and then used as rice bags, etc. Solid weave Polypropylene bags or tubes are the most popular type of container in earthbag building.
Polypropylene is cheap, durable, resistant to rot, water damage and insects. A study reported that polypropylene fabrics may have a half life of 500+ years in benign environments.[6] The tensile strength of such bags is higher than steel,[6] and they are resistant to circumferential forces produced by load bearing.[6] Polypropylene is vulnerable to ultraviolet damage and therefore is left covered from the Sun during construction and plastered once the structure is finished. Polypropylene fabrics may be stabilized/treated are intended to have greater UV resistance, but this may equate to a few months extra survivability in sunlight at best.
Burlap
Burlap sacks are sometimes used, being seen by some as a more organic, "natural" material.[2] However, burlap sacks are often treated with hydrocarbon mold inhibitors which can cause allergic reactions in some individuals.[7] Burlap sacks are not as durable,[2] and are vulnerable to rot.[8] Burlap sacks can be more expensive relative to polypropylene.[2]
Mesh
Mesh tubes have also been used, for example, the hyperadobe technique.
Filler material
The nature of the fill material determines the structural and thermal properties of the wall. For example different fill materials may provide thermal mass effect (dense fill materials) or insulation (porous, air filled materials).[8] Earthbags containing gravel may also act as non-wicking, partially insulated foundations.[8]
As a general rule the weaker the fill material, the stronger the fabric of the container must be.[2] For instance, a hard setting filler such as adobe relies little on the containers. Once adobe is fully set, the containers could be removed without any reduction in structural integrity.[2] Conversely a very fine material such as dry sand relies entirely on the long term strength of the material used to contain it.[2]
The make up of soil can be assessed without special equipment via simple tests such as the drop test and the roll test.[6]
Adobe
The superadobe and hyperadobe methods utilize adobe earth as a fill material. With regards superadobe, the contents of the bags settles into its permanent form within 3 days.
Earth
Most types of subsoil are acceptable for use in earthbag construction and a precise ratio is not required.[7][6] A typical ratio is 25-30% clay, 70-75% sandy soil, 10% moisture.[7][6] Clay is required to bind aggregates together.[7] A mix with over 30% clay may be unstable,[3] and must be kept dry to handle and may slump if it becomes too moist.[6] High clay content soil is also harder to dig and to fill into bags.[7]
The Materials
- Containers (i.e. Bags or tubes)
- Filler material (usually earth)
- Barbed Wire (4 point galvanized)
The Tools
- Shovels
- Tamping tool
- Bricks/weights
- Nails/wire
- Buckets
- Hose
- Sheetmetal Slider
- Pliers
- Ladder
- leveling board
- Hoes
- Rubber mallets
Procedure
Foundations
References
- ↑ 移至： 1.0 1.1 1.2 History of earthbag building on earthbagbuilding.com by Kelly Hart
- ↑ 移至： 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 Building with Earthbags. Joseph Kennedy. 1997 (available on earthbag building.com)
- ↑ 移至： 3.0 3.1 3.2 Earthbag Building: The Tools, Tricks and Techniques. Kaki Hunter, Donald Kiffmeyer. New Society Publishers, 1 Jun 2004
- ↑ Building with Unbonded Pumice by Klaus Grasser / Gernot Minke published by Deutsches Zentrum, 1990 (reproduced on earthbagbuilding.com)
- ↑ Biography of Nader Khalili on calearth.org
- ↑ 移至： 6.0 6.1 6.2 6.3 6.4 6.5 6.6 Earthbag Technology - Simple, Safe and Sustainable. Owen Geiger, Kateryna Zemskova. Nepal Engineer's Association (NEA) Technical Journal. Vol XLIII EC30 special issue on the Gorkha Earthquake 2015 (available on Good Earth Nepal website)
- ↑ 移至： 7.0 7.1 7.2 7.3 7.4 Earthbag Building Guide: Vertical Walls Step-By-Step. Owen Geiger. 2011 (ebook/pdf download)
- ↑ 移至： 8.0 8.1 8.2 Earthbagbuilding.com homepage
Further reading
Books
- Earthbag Building: The Tools, Tricks and Techniques. Kaki Hunter, Donald Kiffmeyer. New Society Publishers, 1 Jun 2004
- Earthbag Building Guide: Vertical Walls Step-By-Step. Owen Geiger. 2011 (ebook/pdf download)
Websites
- EarthbagBuilding.com: Sharing information and promoting earthbag building (website of Owen Geiger and Kelly Hart)
- CalEarth.org The California Institute of Earth Architecture
- Step-by-step earthbag building by Owen Geiger on Instructables.com
- Good Earth Nepal
- Earthbag building on Precision Structural Engineering website
Videos