Concreting future opportunities

[Article by Nane Zietsman]

Mr Gerius Moelich, a PhD student in the Department of Civil Engineering, has impressed international industry stakeholders with his work in 3D printed concrete. He completed his PhD under the supervision of Prof Riaan Combrinck. “I chose Prof Combrinck as a supervisor because I knew we would work well together and that he would encourage a good work-life balance. He motivated me to explore different research topics before selecting one. Because of this, I had the courage to approach him one year into my PhD to ask if I could modify my topic. This is not something that is typically done but he fully supported me,” says Mr Moelich.

According to Prof Combrinck, 3D printing with concrete deposition is a new idea that addresses many issues in conventional construction. “It is somewhat of a hot topic in the industry at the moment. A lot of research has been done on the technology and science of 3D printing, but we have not seen many efforts to investigate and understand what happens to the concrete once it’s been exposed to the environment. Mr Moelich’s work identified the occurrence of early cracks in printed concrete – a topic that has never been covered in a doctoral study before and one that is of great value to the industry,” shares Prof Combrinck. Mr Moelich explains that when concrete is printed in hot environments, severe cracking occurs within the first few hours after placement, and the bond strength between filaments reduces significantly. His research successfully addressed these issues, resulting in many career-advancing opportunities.

During his PhD, Mr Moelich was involved with the publication of 10 journal articles. Some of the journals in which these articles were published include Cement & Concrete Research, Composites Part B: Engineering, and Construction and Building Materials. Apart from the journals having a high impact factor, they are also known for seeking out original, innovative, and ground-breaking research: “These journals are extremely difficult to get into. Getting articles published says a lot about the value and standard of one’s work,” comments Prof. Combrinck.

When it comes to 3D printing, South Africa does not have the financial infrastructure to acquire the latest equipment and machinery, but our industry and academia are known for possessing some of the best fundamental knowledge in the field. It therefore comes as no surprise that Mr Moelich’s work caught the attention of several leading international companies. “Gerius’s training at Stellenbosch University gave him a skill set with which he can compete on any international level. His work is of global standard and the interest he received from some of the key players in 3D printing technology testifies to this,” says Prof. Combrinck. Mr Moelich is currently working for a construction start-up called COBOD International, in Copenhagen Denmark, as a 3D concrete printing material scientist. “COBOD is taking 3D concrete printing to real world construction and has clients on almost every continent. We primarily manufacture and sell construction 3D printers, but also advise our clients on the materials and construction process,” shares Mr Moelich.

Mr Moelich has big plans for the future, and rightfully so: “I plan to stay in Copenhagen for a few years, working for COBOD to gain as much experience as possible. I hope to return to South Africa at some point to address the lack of lower- and middle-income housing with 3D concrete printing,” says Mr Moelich. Ending off his chapter at Stellenbosch University, Mr Moelich acknowledges those who contributed towards his education: “I want to thank my supervisor, lecturers, classmates, and peers for the role they played in my success. Without them, I would not be where I am today.”

As said by Prof Combrinck, Mr Moelich’s success should inspire young engineers who wish to do impactful work: “There are infinite opportunities out there for hardworking students. As shown by Gerius’s achievements, our students are more than capable to compete and thrive in the global arena. The training we give them is of world-class standard and they can enter the industry knowing that they do not have to stand back for colleagues who have studied at any other international institution.”

Photo left: Cracks in 3D printed concrete.

Photo right: Mr Gerius Moelich printing 3D concrete samples at Stellenbosch University.