In the beginning Prof. Dr. Dirk Hebel, professor for sustainable construction at the Karlsruhe Institute for Technology (KIT) kicked the event off with his presentation “Nature and Technology”. In his short introduction he outlined how the highest urbanization rates coincide with the highest emergence of bamboo. Looking at developing countries which often import building materials from developed countries, bamboo could satisfy the need for an alternative, locally available construction material.
“The need for bamboo is today more urgent than ever.”
Also, outside of developing countries, bamboo is a very promising and interesting building material which offers many advantages. Bamboo belongs to the family of sweet gras and hence has a hollow core, which makes it light and pliable. As Prof. Hebel explained, bamboo not only regrows once it is harvested (after 3 to 5 years), it also captures a lot of CO2 due to its high growth rate. In addition, the mechanical properties of bamboo enable it to excel steel in terms of strength and strength to weight ratio. As the plant is often infested by so called “bamboo bugs”, bamboo must be treated with water-soluble minerals (borates) before being used as building material. However, these borates are currently the subject of criticism. To use bamboo in concrete for construction, Hebel and his team are testing bamboo composite reinforcements by experimenting with glued bamboo (using 90% biobased glue) in the Advanced Fibre Composite laboratory of the KIT. “The need for alternative building materials like bamboo is today more urgent than ever”, Hebel reiterated at the end of his presentation, especially pointing to the current building material crisis.
Following this introduction, the next speakers presented specific use cases of bamboo in a building context. Installation artist Markus Heinsdorff shared insights into his impressive bamboo installations many of which are based in China, India, and Thailand. By using bamboo and steel connectors Heinsdorff has built pavilions exhibited at the Expo 2010 and the so called Sykplace – an open room construction made of bamboo only in the form of an airship which is placed in the water, conveying the feeling that one is pending.
Enabling locals to build by themselves
Andrea Klinge from ZRS architects (Berlin) who is specialised in sustainable construction, experimented for her bamboo project “Green Utopia” in Milan even with hemp rope for connecting nodes instead of metal, to focus on sustainable building materials only. The result was a hyperbolic tower, 8m high, installed in less than 72 hours. While this installation, which has now been moved from Milan to Berlin, is used as an exhibition piece, the second project that Andrea Klinge introduced, is highly practical. In Pakistan, in the region of Punchab, she was responsible for building 2-storey school with 8 classrooms. Built on a brick foundation the rest of the school is built completely of bamboo – with a cob and bamboo construction on the ground floor, a 3-layered bamboo ceiling and bamboo and clay walls. The ceiling enables a natural ventilation within the building, which is extremely helpful in the local climate. “We like working mainly with hand tools so we can train people quickly”, Klinge added and strengthened her focus on enabling locals to build by themselves. Klinge sees bamboo as a pioneering plant that can be used to enrich soils again for other plants and crops.
Bamboo changes the image of Medellin
Next up was Nina Pawlicki, who is also part of the Natural Building Lab in Berlin. Pawlicki and her colleagues try to rethink the way we live and work for example by using local building materials like bamboo instead of importing other materials for their projects. One of these projects is the Taller Tropical project in Medellin (Colombia). The city of Medellin, mostly famous for Pablo Escobar and the many crimes of his drug cartel, is slowly trying to change its image. As Pawlicki explained, more and more young architects strive to bring a different kind of architecture and look to the city. Following this vision, Pawlicki and her team built an environmental education centre on top of another building, using bamboo. This building demonstrated the flexibility bamboo can offer, as the entire centre can be reconstructed and dismantled and then be rebuild elsewhere with only small efforts.
Growing Bamboo as building material in Europe
In the final presentation, Stefano Martinelli, head of the Italian company bambuseto, showed that the cultivation and use of bamboo can be brought to Europe as well. By using bamboo for temporary installations, interior fitting solutions and own product designs, bambuseto is trying to show the broad variety of use cases of bamboo. In addition, Martinelli and his team are also involved in the madeinbamboo network collaborating with universities to establish bamboo as a construction material and insert it into ISO rules.
Once again there was a great and productive discussion taking place during and after the web seminar, reflecting the high interest in bamboo as building material. One of the big challenges remaining is increasing this interest and raising awareness for bamboo worldwide. As Markus Heinsdorff summarized: “in poor regions modern architecture will have to provide a perspective and alternative to the construction methods of rich countries”. As it is one of the alternative construction materials locally available in many developing countries, bamboo could contribute essentially to reducing imports of construction materials.
The next web seminar of the “Building materials of the future” series takes place on June 18th in German and will deal with secondary building material. Registration is still open for this and the last web seminar on July 8th.