How PhD Student Niklas Pelka Aims to Revolutionise Construction with OTTO WULFF

Erik: Moin Niklas! You’re currently in the media as a PhD student. So why?

Niklas: It’s because the Universities of Applied Sciences (HAWs) in Schleswig-Holstein have recently been granted the right to award doctorates. This has already been the case in other federal states, where graduates can pursue a PhD at a university. Schleswig-Holstein has now followed suit with the Schleswig-Holstein Doctoral College, which has various research teams you can apply to for starting a doctorate at a HAW in the region.

There is always a university professor involved, and perhaps the special feature is that the thesis is ultimately examined by external reviewers rather than the supervisors themselves.

Erik: So it’s a completely new process for Schleswig-Holstein. And you’re now the first candidate. How does that feel?

Niklas: Being the first is special, of course. It’s exciting, but it wasn’t planned. It felt like: the day after tomorrow is the meeting, who else wants to submit? So we quickly gathered all the documents and submitted them. There’s a bit of pressure, but I’m mainly just happy to finally get started.

Erik: OTTO WULFF is your practical partner. What role does the company play in your PhD, and how does the collaboration work?

Niklas: OTTO WULFF naturally has a supervisory and advisory role. There’s a supervision agreement signed with the first and second supervisors (Prof. Dr.-Ing. Raphael Kampmann from TH Lübeck and Prof. Dr.-Ing. Stephan Görtz from FH Kiel). The main goal is to draw on the company’s expertise. This includes technical consultation, support, and quality assurance of my work. The research topic was roughly agreed in advance, and having OTTO WULFF as a practical partner adds real value, especially in the construction industry, which thrives on practical experience. I’m really looking forward to working with them.

Erik: You mentioned your topic choice: Your PhD focuses on “sustainable concrete.” What’s important to you?

Niklas: Concrete is a versatile material that can take any shape and is simple in its basic composition, but advanced concrete technology is demanding and sensitive. Concrete is never the same and always presents new challenges, which makes it fun to work with. Its disadvantages, like CO2 emissions, are also important. When I learned about the CIRCuit project supported by the company, I was inspired. I believe there’s a need for further research on recycled concrete, which is why I decided to get involved.

Erik: What questions are you aiming to answer with your research? What are the key issues?

Niklas: The main area is the sustainable and resource-efficient use of materials in construction, focusing on concrete. Concrete is the world’s most widely used building material, but it also contributes significantly to CO2 emissions. My aim is to develop innovative, resource-saving concrete. The focus is on reviewing and extending the limits for recycled aggregate, as current standards seem too restrictive and outdated.

We’re asking whether it’s possible to relax these standards or replace 60, 70, 80 percent—or, as we’ve done in Richardstrasse at OTTO WULFF, even 100 percent—of natural aggregate with recycled aggregate. Is 100 percent truly the future, or perhaps only 80 percent? Another focus is incorporating recycled materials or industrial by-products to improve concrete properties and sustainability. The goal is a holistic circular economy, even looking beyond the construction industry.

Additionally, I want to explore alternative reinforcement and combine it with concrete. The ultimate goal is to implement resource-saving concrete on a large scale in a pilot project and test it in practice.

Erik: In other words, your research could influence daily work at OTTO WULFF and the industry, because materials affect the entire footprint.

Niklas: Exactly. The aim is to develop resource-efficient, innovative concrete that contributes to a holistic circular economy. Recycled concrete won’t replace every component, just as alternative reinforcement won’t replace steel in every case. Environmental conditions and durability requirements always matter. But there are areas where recycled concrete makes sense, and I think the outcome will be very interesting. Who knows—maybe we’ll end up with concrete that outshines standard concrete.

Erik: How do you envisage the timeframe for your PhD and research?

Niklas: It’s hard to say, but if everything goes well, it should take around three years. I expect three to four years, depending on whether experiments are long-term or short-term.

Erik: Are there specific challenges you anticipate?

Niklas: Recycled concrete behaves differently, especially during processing. I can develop the best concrete in the lab, but its quality also depends on mixing, installation, and how it arrives on site. It’s not just me as a doctoral student—it’s about all of us working together to create a product with a promising future.

Erik: Thank you for speaking with us, and all the best for your research!