MODULAR CONSTRUCTION

Population growth all over the world makes governments take measures to provide housing for the population. Therefore speed and costsavings in the construction of buildings are priority purposes of all construction companies. The main aim of this research is to analyze what extend modular construction method can be a solution to such a challenging task.

The feature of modular construction method is that it involves constructing sections away from the building site and then delivering them to the intended site. This process is regulated by the same codes and standards as it is with conventionally built facilities.

Such way of constructing has been around for almost 200 years, for example in 1837 Henry Manning, a British carpenter, built components for a “Portable Cottage” in London, and then shipped them to Australia. For the first time, using of modular construction technologies in commercial volumes was launched in 1930`s-40`s during the World War II in Europe and the USA. British cities being destroyed, the state needed the technology of prefabricated residential houses. Many American soldiers also settled in similar houses after war.

The growth of the urban population in the Soviet Union in the period of 1950-1960 also was the drive for search for new solutions in the rapid erection of buildings. Thus, the first factories for the production of block modules appeared in the form of a whole room. Currently, the technology of Voronezh plant allows constructors to create 17-storey residential houses [1].

Nowadays, modular technologies are widely used in low-rise buildings of different functional purposes: warehouses, sanitary units, offices, households and etc. Moreover, in recent years, they have been introduced in high-rise and multi-story buildings.

At present, there are two basic ways in the construction of modular buildings:

• Prefabricated building construction systems. The main idea of this method is that the separate elements of a frame system are produced offsite, but assembled onsite. As elements of frame usually are used beams, floorings, columns, wall panels etc.
• Modular buildings of 3D blocks. In this case, prefabricated block containers or 3D elements are originally manufactured at the factory, including exterior and interior finishing and built-in equipment and furniture.

The potential benefits of modular construction technology are as to follow:

• Speed of construction. Up to 50
•  % of reduction of the overall completion schedule can be achieved through the use of modular construction, inasmuch as the building and work site can be completed at the same time. The floors, rafters, walls and ceilings are built simultaneously and then assembled together to form a building, in the same factory.

Figure 1. Difference between Modular Construction and Site Built Construction scheduling

• Cost saving. Savings in labor costs are possible, by more efficient use of labor or by avoiding higher wages. Standardized parts can reduce overall design fees and a more predictable construction program reduces the risk of increased costs due to delays on site.
• Indoor construction. Assembly of structure takes place in enclosed space, independent of weather. Consequently, this increases work efficiency and allows avoiding damage to building materials.
• Environmentally friendly construction process. Construction of modular dwelling generates much less waste compared to site-built dwelling, which may take just several large dumpsters. According to the UK group WRAP, this can reduce the use of materials by as much as 90 %.
• Flexibility. Technology allows builders continually add to a modular building, including creating high-rises. When necessary, modular buildings can be disassembled and modules relocated or refurbished for further use.
• Quality. Factory production is able to produce thermally efficient, airtight and more durable structure. Also, any possibility of high levels of moisture in the framing materials is excluded.

One of the problems of modular construction is the lack of effective competition. Suppliers try to maximize their profits, so in supply-limited markets prices will rise to match the cheapest alternative, usually conventional construction [2]. Another disadvantage is volumetric: due to transport and manufacturing restrictions, the module size can be limited, affecting room sizes.

Figure 2. A New York Residential house

The rapidly developing modular construction technology has already established itself in the construction of skyscrapers, so in 2014, 359 feet high residential building was built in central Brooklyn, New York,which at the time of construction was the tallest modular building in the world. But in 2015, the Chinese firm Broad Sustainable Building erected an even higher 57-storey modular skyscraper Mini Sky City, intended as a hotel. Construction took only 19 days, not considering the preparation of the working site. Distinctive feature of this building is its strength, which allows it to withstand strong earthquakes.

Another future plan of this firm is to build a much larger project, Sky City, which is intended to be 220 storeys tall.

The development and achievements in the field of building materials allow engineers to improve the technology of modular construction, making it more profitable and effective in the rapid erection of buildings, and it also becomes possible to use this technology in the construction of skyscrapers. Proper popularization of this technology in construction circles will make it possible for the construction industry to reach a new level. We hope for sure that soon the purchase of an apartment in a skyscraper will be not a dream, but a reality for ordinary people.

References:

1. Generalova E.M., Generalov V.P., Kuznetsova A.A. Modular buildings in modern construction [electronic resource]. – Access mode: https://core.ac.uk/download/pdf/82404423.pdf (free access).
2. Hyams A., McCan E., Ferguson H. Construction methods: modular [electronic resource]. – Access mode: https://www.building.co.uk/data/construction-methods-modular/5094760.article (free access).
3. Batukov S.A. “Перспективные направления развития строительной отрасли России // Российское предпринимательство”-2008.-Volume 9.-№ 12.-P.102-105.