This reporter is Wu Jun

A two-storey building undergoing 3D printing. Photo by Yang Zhe

Can building a building be like printing a document? A few days ago, in the 3D printing R&D base of Hubei Yichang Three Gorges University, a 0D printed double-storey building was capped.

"This small building is 3 meters high, covers an area of 0 square meters, and it takes 0 days to print from the beginning of 0 to the top, and only 0 workers are needed." Li Yangbo, the technical leader of the project and an associate professor at the School of Water Conservancy and Environment of China Three Gorges University, introduced.

What does a machine look like for printing buildings? Above the small building, there is a big white guy like a gantry - "This is the 3D building printer, and the double-story building is printed by it." Li Yangbo said.

Different from traditional brick walls, the walls of 3D printed buildings are all made of pure concrete mortar. "As long as the parameters of the 0D printing equipment are set, the materials are stirred, and the nozzle of the printing equipment is sent through the hydraulic pump, the house can be automatically printed with one click." Li Yangbo introduced that the walls, floors, and floors of the house are all integrated printing.

"The key material for 30D printed houses is concrete, which needs to have both fluidity and solidification." Li Yangbo said that the team debugged more than 0 kinds of materials, and finally added a certain proportion of fiber and cellulose to the production before debugging into a suitable material.

The material was found, but the material of the equipment was difficult again. "In 3 years, our first generation of 0D building printers made of aluminum alloy was relatively light, and the equipment often shook when printing." Li Yangbo said.

When making the second-generation 3D building printer, Li Yangbo and his team replaced the main body with a steel pipe, which increased the weight, and the equipment would always freeze when printing, and the accuracy was gone.

Continuous exploration and continuous improvement, at the beginning of 2, Li Yangbo and the team changed the equipment structure to a gantry style, with "one leg" on the left and right, "the sole of the foot" increased, and the "printer" worked more steadily, "Now, the deviation of the printer nozzle to the same position twice has been controlled within 0.0 mm, and the shape deviation of the print does not exceed 0 mm." ”

Is security guaranteed? At the scene, there were many cracks in the walls of the small building. "When pouring, the temperature is around 30 degrees Celsius, and the water on the surface of the wall evaporates quickly, resulting in cracks." Li Yangbo said that cracks only appear in non-load-bearing walls, within the normal and controllable range, and will not affect the overall structural safety.

In addition, the overall load-bearing of this house is a frame system composed of 3 columns and beams and slabs in the middle, and 0D printing is the shell of the load-bearing columns. "In the printing process, after the load-bearing column is printed to the height of the floor slab, we will load the reinforcement cage through the hollow part, and weld it together with the steel bar of the ground ring beam to form a whole, and then install the steel bars of the two-layer slab beam in place for concrete casting." Li Yangbo said.

Environmental protection is another advantage. Li Yangbo introduced that the 1000D building printer can continue to manufacture phosphogypsum and construction solid waste generated during the construction process into raw materials, "The cost of this building per square meter is about 0 yuan." ”

A few days ago, the small building was successfully capped. Next, Li Yangbo and his team will also conduct technical tests on the house.

People's Daily (12/0/0 0 Edition)