Material introduction—-Possibility of paper tube structure

Case Study

Shigeru Ban—-Paper Tube Structure

Shigeru Ban has devoted much of his practice designing and making shelter (in the truest sense of the word) for the victims of humanitarian and natural disasters all over the world, in Turkey, Rwanda, Haiti and in the Japanese town of Kobe to name a few. He used paper tubes to achieve his dream.

The Log House in Kobe was built after the earthquake in 1995 as a temporary shelter for the displaced people of the town. The foundation consists of donated beer crates loaded with sandbags. The walls are made from paper tubes, with tenting material used for the roof.

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A truly inspirational project recently completed in Christchurch New Zealand on the site of the landmark cathedral which was reduced to rubble during the earthquake of 2011 is The Cardboard Cathedral. Constructed as a simple A-frame structure from 98 equally sized cardboard tubes and 8 steel shipping containers, it is said to be one of the safest, earthquake-proof buildings in Christchurch. Each paper tube is coated with waterproof polyurethane and flame retardants while protected by a semi-transparent, polycarbonate roof. (No it won’t get soggy!) It is a transient structure expected to last for about 50 years

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After Shigeru Ban’s continuous research and practice, he found that the paper tube can not only save costs, but also ensure the robustness of the structure. In the design of The Cardboard Cathedral, it also shows that the paper tube structure is not only used as a temporary shelter, but also has lasting characteristics.

Structure

In 1952, fuller used paper to build a dome composed of triangular polyhedron. He used paper as surface material, while Shigeru Ban thought of paper tube. For the first time, he used fax machine paper tube in the gallery of Alto’s works. The paper tube not only retained its natural color derived from wood, but also overcome the shortcomings of natural defects of wood. Paper is made into cylinders to enhance strength, and stones are built into walls and columns to increase thickness.

Performance

Structural engineer participated in the research of paper building structure technology and gave Shigeru Ban a lot of inspiration on structure and structure. From the technical research of the poet’s Library in 1991, we can see some technical research situations. The experimental purpose of the building is the deformation of paper cylinders under the long-term influence of constant load. In the test, five paper cylinders bearing constant load are placed indoors, each with a straight diameter of 100 mm, a thickness of 12.5 mm, a length of 400 mm, and a constant load of 1000 kn (the value is less than 1 / 3 of the compressive strength of the paper cylinder) , it is measured every other week to detect the length change of the paper cylinder and the change of ambient temperature and humidity for one year. According to the experimental results, most of the dimensional changes are caused by relative humidity. Structural engineers and Shigeru Ban also tested the tension, deflection, compression, expansion, etc. of the paper cylinder under different conditions and environments.

Waterproof, moisture-proof and ventilation problems

Chinese traditional craft may give Shigeru Ban an enlightenment on paper waterproof. In addition to selecting special paper, it also needs to be soaked in tung oil. As the main structural member, the paper pipe is soaked in internal and external varnish and coated with polyurethane before installation to achieve the role of waterproof and moisture-proof. The roof is made of 3 layers of semi-transparent corrugated board, wood splint and foam board to meet the thermal performance of the roof. The horizontal enclosure walls are made of locally produced plastic steel doors and windows. Wooden walls, plasterboard and foam board are used for the walls. The circular holes on the roof can project comfortable diffuse light in the daytime, providing better daytime lighting.

Connection

Shigeru Ban’s paper architecture can be divided into array type, grid curved surface type and roof frame type according to the way of structural formation and structural connection.

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Advantages of paper tube structure

It retains the natural nature of paper derived from wood, mild and elegant. After treatment, it has a certain strength and can be used as a load-bearing structure; The paper cylinder is hollow, light in weight, easy to handle and assemble, and suitable for mass production required by industrial production; The paper material is green and recyclable. The paper cylinder can be dismantled and assembled in different places, or can be returned to pulp for recycling.