The conventional way of construction faces various challenges like less productivity, restricted design, high construction cost, construction waste, conflict among the construction workers, and prolonged construction time. While the world is moving towards automation, efforts are being made to automate the construction industry through various technologies. Additive manufacturing in construction commonly known as 3D concrete printing is one of them. It is emerging as a potential construction technique throughout the world because of the advantages this technology has to offer. Many developed countries are shifting their mode of construction to 3D concrete printing. This technology compared to conventional construction reduces the construction cost from 40% to 50%. Many countries are utilizing this modular construction technique for the mass construction of housing units and various architectural elements.
This mix design used by this technology has ingredients the same as conventional concrete but with modified rheological properties to assist in extrudability, buildability, pumpability, and interlayer bonding of printed specimens. In simpler words, it should have that much workability to be forced out of the nozzle ( low value of dynamic yield stress), but upon settling it should be able to bear its own weight and the weight of subsequent layers added upon it ( high value of static yield stress). Almost all of the materials required in mix design are easily available locally.
Pakistan is a developing country with an expected expansion of 92% in the construction industry. Construction accounts for 2.53% of the total GDP of the country. With its increasing population, there is more pressure on the construction industry to increase its productivity. It is estimated that there is a current housing shortage of 10 million which is expected to increase up to 13 million by 2025. If fully incorporated into the construction sector, 3D concrete printing offers an inevitable solution to this challenge. Considering the aforementioned crisis, students from NUST, Raja Dilawar Riaz, Usama Majid, Ammar Ali, and Muhammad Faizan under the mentorship of their advisor Dr. Muhammad Usman, HoD Structures & Survey Department, NUST Institute of Civil Engineering, have completed the development of Pakistan’s first 3D Concrete Printer.
This indigenous 3D concrete printer has a frame size of 1.2m x 1.2m x 1m. Utilizing its 3-axis movement controlled by servos and gearboxes, a variety of nozzles (with a max size of 3 inches), continuous intake capacity, screw extrusion, and a digital control system, it can print a volume of 1m x 1m x 0.5m. This inexpensive concrete printer serves as a prototype for large-scale construction applications. It is capable of printing various-shaped architectural and structural components. The concept of using this printer is very simple. A 3D CAD Model is created on computer software and the model is sliced as per the requirement the mach3 controller in this printer reads the G-Code file and extrudes the layer of concrete. This printer was first time showcased under the theme of “Low-Cost Innovative Housing Technology” at the First International Housing & Property Expo 2022, Islamabad organized by the Federal Ministry of Housing and Works Government of Pakistan.
Development of this concrete printer involved a designed concept developed by few of the literature available and enhancing the output in terms of cost-effectiveness and local availability of resources. The whole development process is an interdisciplinary venture undertaken by this team and completed in the summer of 2022. This challenging task required multidisciplinary knowledge and expertise which this team learned during the development of this printer. During their course of R&D, they have gone through multiple types of research with respect to civil, mechanical, and electrical engineering and come up with the most efficient solutions. Along with its capability to revolutionize the construction industry of Pakistan, it has widespread potential for sustainable construction and modern research…
Advantages:
This unique prototype of the 3D concrete printer is designed to provide multiple advantages in the construction sector such as:
- Design Flexibility
- Topological Optimization
- Increased Productivity
- Reduced labor effort
- Greater research potential
- Highly precise deposition
- High-end technology-based jobs
- Multifunctionality of structural/architectural elements
- Cost-effective mass housing solution
- Energy efficient
- Promising methodology & output
- Safer construction work
- The balance between beauty, form & function
Owing to the advantages offered by this technology and the success of the development of a 3D Concrete Printer with locally available materials, it is undoubted that this technology will soon revolutionize the construction practices in Pakistan.
Video Demonstration of 3D Concrete Printer
Team Members:
Dr. Muhammad Usman
Project Supervisor
Associate Professor & HOD Structures, Survey Department
NUST Institute of Civil Engineering
m.usman@nice.nust.edu.pk
Research Profile: https://bit.ly/3GJFf6f
Dr. Jawad Aslam
Project Co-Supervisor
Associate Professor
NUST School of Mechanical & Manufacturing Engineering (NUST-SMME)
jawadaslam@smme.nust.edu.pk
Research Profile: https://bit.ly/3ypEco4
Raja Dilawar Riaz
Group Leader
UG-19 Student
RRiaz.bece19nice@student.nust.edu.pk
Ammar Ali
Team Member
UG-19 Student
AAli.bece19nice@student.nust.edu.pk
Usama Majid
Team Member
UG-19 Student
UMajid.bece19nice@student.nust.edu.pk
Muhammad Faizan
Team Member
UG-19 Student
MFaizan.bece19nice@student.nust.edu.pk
The author is a student at School of Civil and Environmental Engineering (SCEE), National University of Sciences and Technology (NUST). He can be reached at RRiaz.bece19nice@student.nust.edu.pk.
