3D-printed Building in Dubai

Mankind has always been inspired to progress because of its inquisitive mind. But the second part of human consciousness (skeptical) was sure that a good method is a proven method. If we consider in perspective the creation of any landmark invention such as the railway, the car, or aviation it all began by a group of people-enthusiasts, looking at whom, many people twirled a finger and said: “This is impossible!”. 

The first cars and planes really looked more like homemade crafts glued together than products of industrial industry. However, the laws of the market are immutable at all times: if there is a consumer demand-supply will arise sooner or later. After a generation, railways, cars, and aviation which it is impossible to imagine the modern world without.

A similar situation is observed in one of the most conservative industries – construction. Even yesterday the technology of 3D printing in constructions was considered as a funny curiosity that does not have much practical sense, a kind of game of the mind and imagination of engineers. But 3D-printing responded to the tough demand of the market “build faster and cheaper” as well as possible. 3D printing really works, and we can proud of the new printed build, which was fully made by this technology. The company Apis Cor printed an office building in Dubai (UAE), hitting the "Guinness Book of Records".

Features of the new projects

On the instruction of the municipality, we had to build a two-floor administrative building with a height of each floor – 4.7 meters. The total area of the building – is 640 square meters. When we got acquainted with the design project, we understood that the customer did not consider the peculiarity of construction’s 3D printing and that the power of our equipment is not enough. The current prototype was designed for a maximum wall height of 3 meters.

We solved this problem by increasing the height of the boom, which gave rise to a new problem – because of increased height the stiffness of the entire structure decreased. The change of printing trajectory was about 5 centimeters. While we were solving this problem the time to send the equipment to Dubai become. Engineers had got only 2 months to search and manufacture the solution, of which a month was taken by the delivery of equipment to UAE and month to print formwork for the foundation. So, the problem with stiffness had to be solved in parallel.

I suggested creating an additional construction, which will increase the stiffness of the printer system. The printer lift system is based on 3 hydraulic cylinders that lift synchronously. We have created an additional unique mechanism that was flexible when lifting and when stop it makes stiffness construction like a truss. Its installation had to be carried out directly on the construction site because there was no time for searching for a workshop at which all this work can be done. Having arrived with all details and equipment in Dubai, I went with my colleagues to the construction site to finalize the equipment. As if we did not prepare ourselves in advance for the peculiarities of the local climate, it was very difficult at the first time to experience the heat. We were literally in the desert (the construction site is behind the city in the new area under construction), it is June, the temperature reaches 50 degrees Celsius. It is physically impossible to stay under the sun for more than 20 minutes. So, most parts of the work we did at night illuminated the site with a spotlight. After installation of an additional truss for stiffness, we solved most of the problems associated with the error in the trajectory and insufficient stiffness.

Arriving in the UAE, we realized that we need to develop new material for printing because we can not use the same mixture, which we used to print house in the Stupino. The mixture technologist has developed a new mixture based on gypsum from local building material and taking into account the specific climate of the UAE. While we were engaged in the revision of mechanical parts, and technologists was developed and tested new formulations of the mixture for printing, a focus group of engineer-builder, architects, project managers adapted the project documentation to the peculiarities of the construction method and the dimensions of the equipment. They also faced a big task: it is necessary to synchronize and optimize the trajectory of printing when moving the printer on the construction site. Because the floor area of the building is more than 300 square meters, it was necessary to make several rearrangements of equipment and synchronize the code so that rearrangements will not affect the quality of construction.

In addition, it was necessary to adjust the trajectory of printing taking into account the laying of vertical reinforcement of walls, laying of communications, installation of ceilings and jumpers for windows, doorways, and columns. Bypassing the vertical reinforcement occurred due to improvements in the printing code.

During the printing of the building in Dubai, most of the work on the bypass armatures was carried out manually. Based on our experience and data, in the future, we are going to develop a machine vision system to automatically detect obstacles and bypassing them. All work for trajectory optimization formed the basis of the new software for making G-code.

Before the final printing of the building walls, we conducted several tests on the printing of different constructions to be sure in the performance of all units and compliance with the requirements of maximum height and radius of printing. We had to be sure at all: in mechanics, hydraulics, feed system, mix quality, correct code and etc. After that finally, we started to print the walls of the first floor.

At the beginning of printing the main building, we always checked the condition of the equipment. Based on this data we have finalized the technical documentation for maintenance and working with the printer. It was not a serious problem with mechanics, but it was always necessary to make allowance for the fact that when we were creating the equipment in Moscow we knew very little about the climate of the Emirates.

The main problem of the climate in Dubai – is the constant transition of the temperature through the dew point. Simply put, in one night every metal surface was covered with a coating of rust. The solution was obvious – to choose a lubricant that would prevent corrosion. With all the evidence of this decision, we had a lot of trouble. In the desert, a strong wind carries huge amounts of sand, so it sticks immediately on the freshly applied lubricant, which is very harmful as guides and bearings. After trying dozens of options, we found a suitable lubricant and began to apply it. It was a lubricant for a motorcycle chain in the form of a spray, having excellent protective properties, high viscosity, the sand did not stick to it. Subsequently, taking into account the experience in Dubai, when designing new models of the printer, we began to use stainless steel guides – this is quite an expensive solution, but significantly increases the service life of the node.

The main works of printing of the building were made by a team of four people: project manager, software developer, architect, and engineer. We joked that we were taking part in racing “Paris-Dakar”. The comparison was perfect – absolutely terrible weather and climatic conditions and incredible load.

The printing of the final building fell within 500 hours of machine time – 8 hours per day. Previously, we could not afford such a luxury - to print as much time as convenient. At the very first printing tests back in Moscow, we tried not to stop the printer, as after each stop it was necessary to do a lot of works: washing of all hoses, printer routing, kneading system, and feeding the mixture. When printing in Dubai - we already had sufficient experience and many of the procedures were automated. Sometimes it was necessary to take breaks in the printing for several days or weeks because the General contractor need to laid fittings, isolation, communications, and ceilings. Installation of ceilings was carried out in the traditional waylaying of a slab by means of the crane. After printing the 1st floor, the ceilings were installed, then the printer was installed on the ceiling and started printing the 2nd floor.

The building printed in Dubai, unlike the house in Stupino, will be put into use and there will be the offices of local companies. This building is the first printed building in the new region of Dubai and the municipality plans to "print" the whole region.

During the project, we were faced with technical problems, organizational difficulties, and sometimes waves of skepticism and misunderstanding. But anyway, the printing of the building was successfully completed in August 2019, after which the General contractor moved to the execution of finishing works, and the presentation of the finished building took place in October 2019. The building was included in the Guinness book of records as the largest 3D-printed building in the world. Other large 3D-printed editions already exist, but they were all assembled from prepared blocks, whereas we printed the building "whole" on the construction site.