Building materials are inextricably linked with the inheritance of history and culture, the development of economy, science and technology, and the needs of human emotions. Materials are the carrier of architectural design. The expression of building materials is an important part of architectural design. Since ancient times, in order to improve and change the living conditions and meet people’s material, spiritual, and emotional needs, human beings have been actively exploring new building materials, striving to explore the emotional connotations of architectural materials, and creating a variety of architectural landscape images. There are many studios specializing in building materials, such as Material Systems, Ecologic Studio, etc. (Wilson, et al., 2008)
Human beings are always actively exploring, as new materials emerge in an endless stream, and old materials are renewed with new style. At present, due to the development of urbanization in the world, the urban population is growing at a high speed. It has become the mission of the architects to solve the large-scale and integrated infrastructure construction of the city, catering the diverse needs of the urban population. There are also specialized studies like the Rural Studio in the United States focusing on low cost materials (Dean, Chua, & Robinson, 2002). The future buildings will develop toward higher and larger spans, richer, more ecological, and more humanized and diversified forms. In this process, materials will continue to serve aesthetics, functional, and eco-friendly purposes.
Part One: Aesthetic Purposes
As early as the mid-nineteenth century, German architect Gottfried Semper published The Four Elements of Architecture (Die vier Elemente der Baukunst), and the concept of “dressing” and “textiles” were first proposed for architecture. This is considered to be the prototype of the material weaving theory, and later it was inherited and perfected by many outstanding architects. Adolf Loos was the most important successor of Semper theory at the time. Loos pointed out the importance of wall cladding as a space enclosure and believed that materials have their own formal language and therefore required to distinguish between wall cladding and material decorative cladding. These theories show the importance of the material to the design while showing the relevant knowledge of the building material as a space enclosure (Hartoonian, 2006).
Art is a tool for conveying emotions, and human emotions are the soul of landscape design. The Guggenheim Museum in Spain, designed by architect Owen Gehry, is filled of human emotions in the design. The use of material language expression is based on a combination of traditional and modern materials such as glass, steel and limestone. It used some modern techniques such as crossover, overlap, torsion, and breakage on the exquisite and delicate traditional materials, to show human and emotional details, the prominent modern titanium material skin, the highly personalized high-tech era emotions. It is like a cluster of metal flowers reflected in the river water. The humanistic emotional factors in material language expression are the soul function in design. (Sokol & Mafi, 2018).
Concrete is one of the examples of diverse architectural language. Its form and color can be infinitely changed, and it is a material that can express the aesthetic orientation of design freely. Ando Tadao is known as the Concrete Poet architect. His creation of concrete has been a great success in creating aesthetic designs. For example, the representative of Ando’s classic “Church of the Light” highlights the potential artistic charm of concrete materials. The walls of the church are all made of clear water concrete without any decoration. The solid and thick concrete is absolutely enclosed, and the characteristics of the cold, hard, rough and cool concrete texture match perfectly with the holiness of the space. The material is in sharp contrast with the huge-scale light cross on the wall, showing the seriousness and sacredness of the church, which evokes a solemn feeling (BCF.edu, 2018).
Part Two: Functional Purposes
With the rapid development of modern science and technology, high-rise, large-span, multi-functional construction projects continue to emerge. This undoubtedly put forward higher requirements for the bearing capacity and durability of cement concrete. High performance concrete has become a hot spot for researchers to explore. Carbon Nanotubes have superior mechanical properties and high aspect ratio, showing great advantages in strength, elastic modulus and toughness (Douba, et al., 2019). The application of carbon nanotubes to cement concrete can improve the strength, toughness, and ductility of cement-based composites, significantly improve their durability, and impart many new functional properties such as electrical conductivity and pressure sensitivity of cement-based composites. Research provides a new development space for a new generation of structural and functional composites (Hamzaoui, et al., 2014).
When it comes to paper construction, the name that has to be mentioned is the representative Japanese architect Shigeru Ban. From the Issey Miyake residence in Tokyo, the Japan Pavilion at the 2000 German Exposition, the Nomadic Museum in New York, to the new Pompidou Centre in France, it is easy to see that Shigeru Ban is an outstanding architect with humanitarian care. In his philosophy, paper architecture has a combination of high-tech creation and rich in care and responsibility for the human society. As early as 1989, Shigeru Ban built his first paper tube building, Paper Arbor, which is an outdoor tent at the Nagoya World Design Expo in Japan (Buntrock & Choi, 2001).
Shigeru Ban’s paper buildings are often hailed as a model for new material architectural innovation. But this is not because he used paper to build magnificent museums, or private houses, but quick and more comfortable temporary buildings for the victims of the natural disaster. The emergency response of temporary buildings after the disaster is very significant, but many countries lack regulations on such buildings, as they are often limited by construction conditions and funding. The paper building of Shigeru Ban reflects the unique advantages of the paper material in many ways. Shigeru Ban’s paper architecture is inspiring, with more possibilities to dig deep into the potential of architectural design towards affordability, democracy, and equality (Hales, 2005).
Part Three: Eco-friendly Material
Bamboo has stronger and more flexible properties than steel, and can even cope with the damage caused by earthquakes to buildings. In the ecological building world, Simón Vélez is a prominent name. Simón believes that bamboo is an ideal sustainable building material that has been neglected in the history of modern human construction. He combines traditional Colombian architectural design with ecological technology to form the Simón-style long-span bamboo structure (Rodríguez-Camilloni, 2009).
The history of human use of straw as a building material dates back to Nebraska in the northwestern United States at the end of the nineteenth century. In 1998, architect Jan Sonneveld, who had been exploring the green building model, used straw bricks as a skin to build an eco-house called “Butterfly House” in the Netherlands. He skillfully used low-cost, high-insulation straw materials and underwent continuous extrusion to form a system of strong multi-layered straw boards as the walls (Post, 2018). In addition to the advantages of low cost, high sound insulation and high thermal insulation, the straw material has better shock resistance. Straw material is a natural by-product of crops, which will not pollute the environment, and will not cause harm to people. It not only meets people’s needs for sustainable development of living environment, but also meets the physiological needs of people to return to nature.
Every year, concrete preparation in the construction industry requires the use of a large amount of sand, and global sand resources have shown signs of shortage, affecting the construction industry, glass manufacturing, computer chip manufacturing and other sectors. At the same time, illegal mining also affects the ecosystem. Currently, a research team at Imperial College London has developed a new biodegradable building material that is as strong as conventional concrete and has only half the carbon emissions. The new building materials developed by the research team are based on the sand from the desert. Previously, such sand could not be used directly because it was too fine to hold form (Dezeen, 2018).