ISABEL RUBIO ARROYO | Tungsteno
China has taken just ten days to build a 25,000-square-metre hospital. The aim of the building, which has 10,000 beds, is to isolate the sick and prevent new infections in the face of the unstoppable escalation of the coronavirus (COVID-19) in central Hubei province. This feat has been made possible by putting together dozens of prefabricated modules. But this is not the first time that the Asian country has constructed such a building in just a few days.
How is China able to erect hospitals, hotels, bridges or train stations in just dozens of hours? The key, apart from a huge volume of labour, is in the use of prefabricated materials and modular construction. In most cases, time is saved by using structures that are completely assembled beforehand, with their facades, windows and even their installations already in place.
Once at the site where the building in question is to be erected, the modules are assembled with great precision. Lightweight facades and the use of steel and reinforced concrete structures allow for cost savings and faster construction times than with other materials. In addition, the new building systems serve to create resistant infrastructures that are adapted to the needs of the environment, from withstanding earthquakes to having high levels of energy efficiency. These are some of the structures built in record time:
A hospital in seven days
In 2003, the Xiaotangshan Hospital in Beijing was erected in just seven days. On that occasion, it was intended to respond to the health alert during the SARS epidemic, which was caused by an atypical pneumonia that first appeared in November 2002 in the province of Canton.
About 4,000 people worked day and night to meet the deadline. The first step was to prepare the ground with dozens of excavators and bulldozers. Then it was time for the construction of the building. As with the construction of the hospital for those infected with COVID-19, the key in that case was the use of prefabricated materials.
Workers didn’t lay down bricks, but joined together previously assembled structures. In this way they built, for example, an X-ray room, a computerized tomography room, an intensive- care unit and a laboratory. The hospital was key to the control and treatment of the outbreak that, according to World Health Organization data, left more than 700 dead worldwide.
The new building systems, based on prefabricated materials, allow the creation of resistant infrastructures that adapt to the needs of the environment. Credit: Xinhua.
A 15-storey hotel in six days
In 2010, the company Broad Sustainable Building erected a 15-storey hotel in less than 47 hours. After that, it took about four days to complete the facade and completely clad it. The Ark Hotel is in Changsha, the capital of China's Hunan Province. This record construction time was made possible by the use of steel modules previously built in a factory, which were then assembled like a giant puzzle.
Its builders boast that the hotel can withstand a level 9 earthquake thanks to the diagonal reinforcement of its structure. In addition, they claim that six times less material was used than for a conventional building. The components used are also much lighter than traditional ones.
The walls are airtight and soundproof. The energy efficiency is five times higher than that of an ordinary building, according to the company. To maintain the temperature, the walls and ceilings have 150 millimetres of thermal insulation and the building has triple plastic windows and exterior solar protection.
A 1,300-tonne bridge in 43 hours
In 2015, the Beijing government ordered a traffic overpass to be removed and replaced with a more modern one. The company in charge of doing so demolished the old one, built in 1984, with heavy machinery in just one day. Then it got down to business and erected the new Sanyuan Bridge in 19 hours.
It is one of the most important bridges in the northwest section of Beijing. To build it, 1,300 tons of materials were used. The entire process of dismantling, reconstruction, signage and paving took just 43 hours. In other words, in less than two days the overpass was fully reopened to drivers.
This feat was made possible by what they called the "integrated replacement method". The builders dragged the new bridge into place as a single piece and paved it. A worker interviewed at the time by Shanghaiist explained that if conventional construction methods had been used, traffic would have been affected for at least two months.
For the construction of the new Nanlong station, 1,500 workers and 23 excavators worked tirelessly for nine hours. Credit: Xinhua.
A train station in nine hours
If erecting hospitals, hotels and bridges in just a few days seems surprising, in 2018 it only took workers nine hours to build a train station. That's one conventional workday plus an extra hour. An army of 1,500 workers toiled without rest, and machinery also played a key role. They used 23 excavators and seven trains to create the new Nanlong station in the Chinese city of Longyan.
To do this, they organized themselves into seven teams to carry out different jobs simultaneously; for example, paving the terrain and installing the tracks, traffic signs and even some computer equipment. The project, which was part of a plan to be implemented throughout 2018, connected the city's railway with three other different stations. The infrastructure was designed for trains reaching speeds of up to 200 kilometres per hour and would extend over 246 kilometres.
This work was part of a series of large infrastructure projects carried out by China in recent decades. Among them is the construction of the world's largest radio telescope, located in the province of Guizhou, in southwest China, which has a diameter of 500 metres and began operating in 2016. The country has also completed the Tianhuangping Hydroelectric Project, the largest of its kind in Asia, which plays a vital role in the supply of energy to eastern China.
The system used to make these buildings and infrastructure in record time is not unique to China. In fact, it has been used for years in the West, where the main obstacle to building in a short time is the bureaucratic process. The Paxton Crystal Palace in London was one of the first to be built entirely with prefabricated pieces in the 19th century. The Eiffel Tower, in Paris, was set up in about two years for the same reason. Currently, it is also common in the construction of military and field hospitals for organizations such as the UN Agency for Refugees (UNHCR) or the Food and Agriculture Organization of the United Nations (FAO).
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Tungsteno is a journalism laboratory to scan the essence of innovation. Devised by Materia Publicaciones Científicas for Sacyr’s blog.