Researchers Explore Bamboo-Reinforced Concrete for Walls
Originally published by: Sourceable — March 2, 2016
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The potential of bamboo to dramatically raise the sustainability of the construction sector has long been touted by green building advocates, while use of the material is currently undergoing a renaissance amongst environmentally minded architects.
The gargantuan grass plant grows at an extremely rapid pace and possesses high tensile strength. Its long tubular shape also makes it intrinsically suited for use as a structural component in various building sections.
It has served as a traditional construction material in Asia since time immemorial, and is still frequently seen on building sites throughout the region in the form of sturdy, multi-storey scaffolding structures.
Modern architects are increasingly turning to the organic building material for their latest designs, with one of the most prolific amongst them being Vietnam’s Vo Trong Nghia, who is using bamboo for community centres and spa resorts in South-east Asia.
Bamboo & Concrete
Dirk Hebel, a professor at the Swiss federal Institute of Technology Zurich, believes the sturdy grass plant is also highly viable as a sustainable, economic substitute for steel in reinforced concrete structures.
Speaking at the World Architecture Festival in Singapore last year, Hebel said the use of bamboo in lieu of steel had the potential to “revolutionize our building industry and finally provide an alternative to the monopoly of reinforced concrete.”
His words aren’t hyperbole, given that steel-reinforced concrete is the most widely used building material on the planet, and is still in very high demand in through the developing world.
In order to abet its usage by the construction sector, Hebel has developed a bamboo composite material that is strong and highly versatile, and could serve as an effective replacement for steel in reinforced concrete.
Hebel’s research efforts were at first directed specifically at the construction sectors of developing economies, that consume copious amounts of reinforced concrete for the development of much-needed infrastructure.
Such countries often lack sizeable steel industries of their own to supply the building material’s key structural ingredient, however, making them heavily dependent upon expensive imports from developed economies.
The use of bamboo in reinforced concrete as an environmentally-friendly cure-all for countries that lack their own steel industries, given that it's a hardy, fast growing plant that is particularly well suited to those global climate zones that are host to a large proportion of emerging economies.
Bamboo possesses some of the same sustainability benefits as timber when employed as a building material, because as a form of plant matter, it’s a completely renewable resource that can be rapidly replenished by means of natural processes.
It has its own advantages compared to timber as well, given that it’s harvested from grass plants as opposed to trees. Unlike timber, the harvesting of bamboo does not destroy the plant that produced it, because the root system is left unaffected in the soil.
This means that bamboo does not need to be replanted the way trees are after harvesting, as the root system remains in the soil where it continues to produce new shoots.
In order to better exploit these intrinsic advantages, Hebel has developed a new method for incorporating bamboo into reinforced concrete, making it a more effective replacement material for steel when it comes to shoring up structural strength.
Instead of using bamboo in its natural tubular state as is traditionally the case, Hebel’s method first extracts the plant’s natural fibres before combining them with an organic resin.
This composite material, termed BambooTECH, is highly versatile and lends itself to tooling and manipulation in a manner similar timber once it’s pressed into shape.
When fashioned into thin rods, the composite material can be used as the reinforcing structural matrix for concrete in the same way as steel.
Another major advantage of the material is that unlike steel, it isn't susceptible to rust or corrosion in maritime environments - one of the chief causes of the "concrete cancer" which has blighted many buildings in coastal parts of Australia.
At the time of Hebel’s presentation at the World Architecture Festival, a Singaporean laboratory conducted testing of reinforced concrete made using BambooTECH. In a development hailed as a breakthrough by Hebel, machinery was unable to break the material.
Hebel is far from the only research experimenting with composite bamboo building materials. Researchers at MIT are attempting to use bamboo to produce a structurally sound material that functions in a manner more akin to plywood, by slicing the stalk into smaller pieces to produce composite blocks that resemble traditional timber.
The efforts of these researchers could mean that architect Vo Trong Nghia’s prediction that bamboo will be the “green steel” of the 21st century will be vindicated by the global construction and building sector much earlier than expected.