Humankind is witnessing a constant and drastic change in the construction industry, A change, which constitutes of evolution with respect to the urban fabric, building typology, building materials, etc. This evolution is the result of the process of metamorphosis that inhabitants went through. The use of building materials changes according to the demands of the population which increases with time and diversity in design trends.
In the current situation, architects and designers have a significant duty of selecting ideal materials according to the nature of the project. The material should be environment friendly, sustainable and also should cater to the aesthetic need of the project if required.
The conventional materials used, hardly fulfil these demands and hence, use of the alternative materials is prioritized by the architects.
These alternative materials are customized to meet the aforementioned criteria. These materials are eco-friendly, cost effective, have better functional efficiency, durable, sustainable, etc. These materials are low- maintenance and assure minimum waste production and can be reused or recycled minimizing its harmful ecological damage. They are easy to produce and are less energy intensive.
Cardboard, is an excellent alternative to the conventional building material. It is made from paper which is an environment friendly material, and is easy to treat or recycle.
There has been some uncertainty in the architecture fraternity about the strength and durability of cardboard as a building material. It is generally looked upon as a material with poor properties and strength, it is also considered as a disposable material.
Quoting the Pritzker award winner and the cardboard connoisseur Architect Shigeru Ban,
“The strength of the building has nothing to do with the strength of the material, even concrete buildings can be destroyed by earthquakes, but paper buildings cannot.”
Cardboard, holding true to this statement, performs exceptionally well if proper design techniques and treatments are used. It can be used in many forms as a construction material, namely, paper tubes, honeycomb panel, etc.
Components/ Raw materials
Cardboard is made from wood pulp and recycled paper. The wood pulp is obtained from the trees. Cutting down of trees for the wood pulp is major environmental damage. Hence to reduce this the wood is specifically harvested to meet the demand of the population and not disturbing the ecological balance. It is important for designers and architects to check the source of the wood before using it. The manufacturing process needs water in larger quantity, but majority of this water is reused.
The manufacturing process is done using either of the two methods.
- Chemical method.
- Mechanical method.
The manufacturing process is an energy intensive process.
The energy created by burning the production waste is reused at the plant itself.
The manufacturing process of cardboard is an energy intensive process, resulting in higher embodied energy. The embodied energy of cardboard is dependant mainly on two factors with respect to its architectural use:
- The fibres
Cardboard constituting of natural virgin fibres is highly energy intensive than recycled fibres.
The embodied energy differs according to the transportation cost of the manufacturing process, as the process includes transportation of wood to the pulp manufacturing plants, to the factories manufacturing different parts and components on cardboard to the site. The transportation route may differ for different sites.
The average embodied energy of the cardboard as a building material. Is 27 KJ/KG, this states that the embodied energy of the cardboard is 8 times the embodied energy of bricks and 12% less than that of steel, the most conventional used materials.
Cardboard, with its good thermal insulation properties and with sustainable design techniques have low operational energy consumption. Operational energy consumption is also dependant upon the different components being used like, paper tubes or honeycomb panel, etc.
One of the main advantage of Cardboard as a construction material is its recycling nature. Cardboard can be entirely recycled and the can be reused as a manufacturing component. The recycling process is almost similar to the manufacturing one, but is dependent upon the strength and grade of cardboard. The cardboard already used as a construction material may consists adhesives, resins, coats, etc which can reduce the quantity of the recycled by-product.
Statistics have stated that the recycling process of paper or cardboard takes up to one third to one sixth energy than that required to manufacture a new paper with virgin fibres. It also requires less water and the emission of greenhouse gases and toxic chemicals is reduced in a considerable amount.
Durability of cardboard as a building material is always under scrutiny because of its nature and basic use. Cardboard once treated with proper treatments can function as an excellent thermal insulator, can be made fire resistant which affects the durability and lifespan of the building.
Considering the use of cardboard as a building material by architects in permanent structure in current times, it can be estimated that the lifespan of a permanent structure made up of cardboard is fifteen to twenty years.
Architect Shigeru Ban, mastered the cardboard paper architecture, and has designed several projects irrespective of its nature and use, using cardboard as the prime building material.
Some of them are listed below.
1. The Paper Nursery School, Sichuan, China.
The region of Ya’an city, Sichuan, China, was adversely affected by the earthquake that hit the region in 2013. The school was designed as a temporary structure, which was constructed and built by volunteers. Ar. Shigeru Ban designed this school using cardboard tubes as framework of the structure. The building consisted of two classrooms and a central corridor. L- angles (steel), were used to support truss.
2. Paper log house, India
Paper log house, is an earthquake disaster relief projects by Ar. Shigeru Ban, in the region of Bhuj, Gujrat India. The walls were constructed using paper cardboard tubes erected in a galvanized iron channel. The structure is water resistant. It is made using recyclable and locally available material. The unique quality of this house was its foundation which was made from using rubble that was formed from the buildings destroyed due to earthquake. This made for a better and strong foundation, giving an ecological solution to the debatable issue for the foundation of the cardboard and paper structure.
3. Paper log house, Kobe
This is one of the brilliant projects related to disaster relief housing by Ar. Shigeru Ban. The walls are made up of paper tubes. These paper tubes are 4mm thick and are approximately 106 m in diameter. Foundation is made up of beer crates and sandbags. Sponge tape is sandwiched between the paper tubes. It functioned as an adhesive and a waterproofing agent. All the materials used can be reused and recycled.
4. Paper concert hall, L’Aquila , Italy.
This is a temporary concert hall, built after the region was affected by an earthquake.
Its an oval shaped 700 sq. m hall. It comprises of mainly steel, clay. Cardboard and glass. It’s a simple structure with pyramidal roof. The hall is surrounded by 44 pillars, with an accordion door which opens up into the space and is covered by a red curtain. The hall can hosts 230 people. The structure is temporary and hence an be dismantled, transported and erected again.
5. Cardboard Cathedral, New Zealand
One of the most anticipated projects of Ar. Shigeru Ban, is the Cardboard Cathedral, Christchurch, New Zealand. The region was hit by a massive earthquake bringing down city’s monument.
Ar. Shigeru Ban believes , “People are not killed by earthquakes, they are killed by the collapsing buildings”. This is the ideology behind using cardboard as a building material. The fact of cardboard being a light weight material advocates for the same.
The design constitutes of paper tubes of equal length arranges to form a ‘A-shape’ building pavilion. The tubes are supported by eight shipping containers. The walls are 70 feet in height (above altar). Total of 96 cardboard tubes are used for this cathedral. These tubes are placed with a two inch gap between them in order for light to penetrate inside the church, functioning as an aesthetical quality. The cathedral can host 700 people at a time. This cathedral is the biggest paper structure in the career of Ar. Shigeru Ban.