The intensive growth and more new scientific and technological developments give builders practically unlimited possibilities. But to the fore, the problem of choice comes – how to rationally determine the most appropriate technology? Particularly heated is the debate between supporters and defenders of monolithic construction of prefabricated concrete (bibm.eu, 2016).
The main difference of the prefabricated concrete construction from the monolith is manufacturing of building structures in the factory with careful laboratory monitoring of the whole process (concretenetwork.com, 2016). Impact of human factors on the quality of the product is reduced to an absolute minimum, and perhaps it can be attributed as a significant advantage. Another advantage is also a quick installation of such concrete structures that and does not require a large number of skilled workers at the facility. Thanks to the great voids prefabricated concrete products muffle noise, are better than various technologies for superior carrying capacity and some other mechanical properties. Prefabricated concrete structures are known for the high fracture toughness, excellent ability to withstand dynamic loads and resistance to corrosive influences (concretenetwork.com, 2016).
In the XXI century it is becoming increasingly difficult for architects to realize their unrestrained imagination without the use of advanced building technologies and impeccable materials. Such an ideal material is the architectural prefabricated concrete (drmprefab.com, 2016). The initial liquid form of the concrete allows it to take almost any shape becoming a tool to express creative ideas of the architect. Expressiveness, impeccable quality of details in conjunction with the best architectural concrete properties – strength, durability, heat capacity, excellent sound insulation – result in advanced, first-class facilities (drmprefab.com, 2016).
Various treatment options give the surface of prefabricated elements a very attractive appearance. It can be polished to a mirror finish or treated with acid, after which it turns into a sandy structure. A house may look like a brick one, but in fact to be assembled from prefabricated elements, inlaid with bricks. Inlay fragments of natural stone and ceramics in the precast concrete allows to create extraordinary decorative effects. Modeling capabilities of the material, its feature to transfer a wide range of colors, has a positive emotional effect. Architectural concrete tends to create a favorable atmosphere from such a building constructed with such a technology (hycrete.com, 2016).
Structural features of architectural prefabricated concrete give architects countless possibilities for the realization of their ideas – from balconies, cornices and columns to various elements to the lining which can be carriers, self-supporting, and hinged. Facade panels, according to the developer`s claims, are made as a single layer or a sandwich panels with insulation (weiler.net, 2016). The special surface treatment protects the architectural concrete facades from pollution and graffiti. These facades may be far more reliable in terms of operation and safety, while at the same time to be an example of an elegant, refined and even luxurious architecture (weiler.net, 2016).
One of the important properties of architectural prefabricated concrete is its heat capacity. In the winter and at night when the air temperature drops, architectural concrete with insulation can seriously reduce the loss of heat in the room, and in summer – to protect from the exhausting heat (pcine.org, 2016). It also has excellent sound insulation. A significant advantage of this technology is the reduction of the construction time by the speed of the assembly of prefabricated elements (pcine.org, 2016).
In architecture, there is an approach of chiaroscuro of large deaf planes with components of fractional monotonous motif through the stone lattice type or geometric ornament carpet on the nature of the wall (Cruz 34). The artistic effect of this comparison is the contrast of the massive, heavy stone and brick walls with graceful light and through the lattice; one gives to another a scale, stresses massiveness in one case, and elegance, lightness in another. The stones are made of relatively small sizes and of different configurations – square, triangular, hexagonal, single or double, with thin walls. When laying, changing the relative positions of the stones, an architect can get a lot of options. The effect of pronounced plasticity of the wall is that the sunlight forms a rich chiaroscuro pattern (Cruz 36).
There are instances when facades of large height and length are made of prefabricated concrete structures. In the result architects receive light delicate walls that are practical and beautiful fencing in those cases when it is necessary to provide lighting of the facilities, ventilation, and visibility of the room and protection of it from excessive heating by the sun. Walls of residential and public buildings, railings for balconies and stairs, small forms – this is not a complete list of applications of prefabricated concrete elements in the architecture (Cruz 40).
Volumetric concrete elements allow to complete facades and interiors in a new way, to combine decorative motifs in a variety of variations that emphasize the play of light and shadow. When glazing such volume concrete elements, their bright whiteness contrasts with the pure colors of cast glass (kerkstra.com, 2016).
Architect Paul Rudolph from the USA, during the construction of the Endo Pharmaceuticals Building used an interesting method of treatment of the prefabricated concrete surface. He put prefabricated concrete structures on the carcass previously constructed, and protruded cleaved facets manually, and, as a result of which he obtained the pictorial rough surface. The concrete creates practically unlimited possibilities for surface treatment, since it is a plastic material, which surface can be created by molding, etching, carving and further processing (Croft 47-48).
Smooth surfaces of concrete manufactured in forms are sensitive to slight deformation of the roughness and shape. Therefore, designs with large smooth surfaces require a completely smooth form, for example made of polished concrete. The smooth surface is sensitive to mechanical damage and dirt, and it must be protected from substances which cannot be washed away by rain (Croft 48).
If the surface of prefabricated concrete facade panels is polished in the way that the filling is visible, the final surface acquires a color and texture less sensitive to contamination. The filler is selected according to the desired appearance of the facade plates, at the same time the color can be changed by means of pigmentation. Different shades can be chosen, under which a base material and a filler are in harmony. However, the combination of sharp dark and light tones should not be used. Filler never spreads over the surface completely and uniformly, and a high contrast color of the filler and the rest of the material, for example, when using a black and white cement, causes unpleasant, sharp color fluctuations (Griffiths, “Prefabricated Architecture”).
The use of prefabricated concrete is not necessarily to be linked with a dull gray color. For example, in Sweden, a lot of attention is paid to the color of the filler, and very little – to its form. For example, architects use a filler of uniform color and at the same moment they widely use materials with intense color: brown marble, dark feldspar. They readily use also clinker or mosaics, which give unlimited possibilities for a variety of patterns and colors (Griffiths, “Prefabricated Architecture”).
When using coarse gravel in a combination with prefabricated concrete structures, architects achieve much more expressive and varied surface, since gravel is a mixture of different stones. In Sweden, there is also a widespread method of applying a relief pattern on a concrete surface with the help of cords laid on the damp concrete and treated with special substances (Croft 86).
Very broadly at the construction of housing as well as of office and civil buildings, garages, community facilities and other objects architects use hollow-core slabs (one of the most prominent representatives of prefabricated concrete), stairs (today absolute majority of them is made at plants from concrete), ventilation units, internal partitions. Prefabricated concrete structures are widely used when it is necessary to complete the construction within short terms (Croft 89).
For example, when building of the Olympic Village for the London 2012 Olympic Games, all the exterior walls of buildings located in the Village were assembled from sandwich panels, fully prefabricated and insulated with a layer of foam and the use of architectural concrete for forming the outer surfaces (Croft 90).
Also in London, the UK`s largest super-modern prison was built by full assembly of structures made of prefabricated concrete. Every detention cell (including plumbing elements, beds, and armored windows) was carried out in the factory of reinforced concrete structures as a separate unit. In France, a significant portion of external walls for industrial buildings and shopping centers are made of prefabricated concrete (from both sandwich, and single-layer panels) of a height of up to twelve meters (Croft 93).
Summing up, we can say that, although in the developed countries we cannot often see examples of prefabricated concrete panel construction in its "pure" form, there is a persistent use of prefabricated elements. At the same time, it would be a mistake to attribute unusually rapid growth to a construction using prefabricated concrete structures. The truth is in the middle: architects continue widely apply prefabricated concrete structures when this is required by the technological process and when this does not bring harm to dwellers and aesthetics.
Works Cited
bibm.eu. 2016. Web. 24 Jan. 2016. <http://www.bibm.eu/precast-concrete/10-reasons-for-choosing-precast-concrete?id=1058>.
concretenetwork.com. 2016. Web. 24 Jan. 2016. <http://www.concretenetwork.com/precast-concrete/advantages.html>.
Croft, Catherine. Concrete Architecture. Laurence King Publishing, 2004.
Cruz, Paulo J. da Sousa. Structures and Architecture. CRC Press, Jun 27, 2013.
drmprefab.com. 2016. Web. 24 Jan. 2016. <https://www.drmprefab.com/cement-home>.
Griffiths, Alyn. “Prefabricated Architecture”. Architonic. N.d. Web. 24 Jan. 2016. <http://www.architonic.com/ntsht/prefabricated-architecture/7000680>.
hycrete.com. 2016. Web. 24 Jan. 2016. < http://www.hycrete.com/>.
kerkstra.com. 2016. Web. 24 Jan. 2016. < http://kerkstra.com/faq>.
pcine.org. 2016. Web. 24 Jan. 2016. <http://www.pcine.org/index.cfm/products_systems/architectural>.
weiler.net. 2016. Web. 24 Jan. 2016. <http://www.weiler.net/en/index.php/precast_concrete_products>.
