Research Georgios Pipintakos

Abstract

Asphalt mixture is normally produced using non-renewable, petroleum-based bitumen. However, current sustainability concerns demand a drop in crude oil use. Incorporating bio-based additives from natural origin or industrial byproducts from renewable resources such as bio-oils and lignin offers potential/partial replacement of traditional binders. Nonetheless, the impacts of replaced materials on the final product require a thorough evaluation framework. This project explores 3 areas: applicability, design/performance, and aging/durability of bio-based modified bitumens. It initially examines the extent to which bio-components can replace traditional bitumens, maintaining critical properties. Assessing chemical, mechanical, and rheological performance, as well as emissions is the second key criterion. Finally, identifying their aging, durability, recyclability, and ecotoxicity behavior completes the puzzle of replacing conventional binders. A trans-scale, multilevel analysis framework identifies central facets and establishes compatibility criteria, ensuring required standards are met. The joint effort between Warsaw University of Technology, Antwerp University, and Technical University Wien with expertise in various pavement engineering areas such as characterization of bio-components, bitumens, miscibility, and blending behavior as well as aging, durability, and environmental aspects guarantees the project scientific impact in advancing green/ sustainable road construction.

Researcher(s)

• Promoter: Van den bergh Wim
• Co-promoter: Makoundou Christina
• Co-promoter: Omranian Seyed Reza
• Co-promoter: Pipintakos Georgios

Research team(s)

• Sustainable Pavements and Asphalt Research (SuPAR)

Project type(s)

• Research Project

Abstract

The Robert Oppenheimer Award 2025 laureate is Dr. Georgios Pipintakos, funded biennially by Sticht. R. Blanckaert. The award recognises pioneering research achievements in the domain of exact and applied sciences, with emphasis on interdisciplinary approaches that advance both scientific understanding and societal relevance. The 2025 distinction highlights contributions to the emerging field of asphalt chemomechanics, an area at the intersection of chemistry, materials science, and civil engineering, that seeks to unravel the fundamental mechanisms governing the durability and performance of bituminous materials. The awarded research has established a novel paradigm by integrating state-of-the-art chemical characterisation techniques, such as liquid chromatography, time-of-flight secondary ion mass spectrometry (TOF-SIMS), and nuclear magnetic resonance (NMR), with rheological and mechanical testing, thereby providing new insights into the multi-scale ageing processes of asphalt binders. This chemomechanical approach has transformed the way oxidative ageing, polymer degradation, and material rejuvenation are understood, enabling more accurate prediction models of long-term pavement performance. The work has also advanced practical methodologies, including the development of guidelines for best practices in NMR analysis of asphalt binders, under the auspices of RILEM technical committees. Beyond laboratory innovations, the award acknowledges leadership in establishing global collaborative frameworks. Notably, the creation of the Young Ageing Crew (YAC), an active network of 40 early-career researchers across four continents, which has fostered interdisciplinary exchange during and after the COVID-19 pandemic. Similarly, coordination of the Global Antioxidant Consortium has positioned this research at the forefront of international efforts to mitigate oxidative ageing through sustainable material solutions. These initiatives have reinforced the integration of academic, industrial, and policy stakeholders, ensuring the transfer of fundamental knowledge into applicable strategies for resilient infrastructure.

Researcher(s)

• Promoter: Pipintakos Georgios

Research team(s)

• Sustainable Pavements and Asphalt Research (SuPAR)

Project type(s)

• Research Project

Abstract

Because of the international mission to decrease the use of new carbon-containing resources and to regenerate waste streams, sustainable asphalt pavement solutions will need an alternative for bitumen. A very promising solution to this challenge is found in waste biomasses, as their abundance and structural similarity to bitumen make them a good candidate for partial bitumen replacement. This research will focus on two biomasses and their combination, specifically lignin and waste cooking oil, and their potential implementation in bitumen. Through an in-depth laboratory experimental program, four essential characteristics of bio-modified bitumen will be investigated to lead to scientific-based recommendations for industry stakeholders and future researchers. These four aspects consist of the biomass-bitumen mixing conditions, the short- and long-term chemo-rheological behavior of the bio-modified bitumen blends, their storage stability, as well as their adhesion properties. Therefore, with the completion of this novel and comprehensive approach; procedures and protocols will be proposed regarding the production and assessment of bio-modified bitumen for field implementation. The outcomes of this research will significantly support global sustainability goals such as decreasing carbon footprint while leading to resilient pavement infrastructure.

Researcher(s)

• Promoter: Van den bergh Wim
• Co-promoter: Pipintakos Georgios
• Fellow: Kalama Danai Maria

Research team(s)

• Sustainable Pavements and Asphalt Research (SuPAR)

Project type(s)

• Research Project

Abstract

Worldwide, polymer modification is the most popular enhancement for paving bitumen as it enjoys a number of benefits in its viscoelastic performance. Like bitumen, polymers degrade over time due to the environmental conditions to which they are exposed. These deteriorative mechanisms due to oxygen, UV radiation and humidity are the reason for different distresses of polymer-modified bitumen. Current literature has well addressed this coupled phenomenon of bitumen ageing and polymer degradation from a rheological performance perspective. Little research has focused on the fundamentals behind these deteriorative mechanisms. As such, this project is a game-changer, as it will explore this material from its basis, diving into the 'whys' for such resulting phenomenological behaviour. Beyond state-of-the-art spectroscopic, microscopic and thermoanalytical techniques will first investigate the balance between the two simultaneous phenomena of polymer and bitumen deterioration as well as the role of polymer type and conditioning factors. Next, the effect of the deteriorative mechanisms on the compatibility and stability of the polymer-modified bitumen will be explored. In the last stage, the fundamental input from chemistry will be introduced via multivariate statistics in a predictive scheme for rheological performance, which will be validated in the lab. All in all, this work will propose a complete deterioration scheme for the optimum future design of polymer-modified bitumen.

Researcher(s)

• Promoter: Van den bergh Wim
• Fellow: Pipintakos Georgios

Research team(s)

• Sustainable Pavements and Asphalt Research (SuPAR)

Project type(s)

• Research Project