Dr. Franco Zunino Sommariva

Franco Zunino is a scientist and Swiss National Science Foundation (SNSF) fellow at the Physical Chemistry of Building Materials (PCBM) group since 2022. He obtained his PhD in Materials Science and Engineering from the École Polytechnique Fédérale de Lausanne (EPFL) in 2020, within the group of Prof. Karen Scrivener. His doctoral thesis was recognized in 2021 with the Nanocem 2020 prize, awarded to the best thesis in the field of cement and concrete science worldwide by a panel of international experts. During the same year, one of his papers was distinguished with the Outstanding Paper 2020 award by the board of editors of the journal Materials and Structures. In 2022, he received the Wason Medal, awarded by the American Concrete Institute (ACI) to the most meritorious paper published in 2021 in their journals. In 2023, he was recognised by RILEM with the Colonnetti Medal for his outstanding contributions to the fields of construction materials and structures.

His research revolves around the development of novel, environmental friendly cementitious materials with a fundamental scientific approach. Among his interests are advanced, time-resolved characterization methods of cement hydration, interaction of surfaces with polymers in cement paste, microstructural analysis through electron microscopy and optimization of the production process of clinker and supplementary cementitious materials. In 2022, he received an Ambizione fellowship by the SNSF to develop a new generation of low-carbon, high-performance concrete formulations (namely ultra-green concrete). Within this fellowship, he joined the PCBM group to develop and formulate tailor-made admixtures for these materials (doctoral project of Mr. Paolo Camesasca, supervised by Dr. Zunino).

Ultra-green concrete project (UGC)

This project, funded through an Ambizione fellowship from the Swiss National Science Foundation (SNSF), aims at developing a new family of concretes (UGC: ultra-green concrete) to radically reduce the CO₂ emissions related to this material, substantially beyond the CO₂ savings of any of the technologies currently available. UGC will therefore be the next breakthrough in sustainable technologies for decarbonization of the construction industry, saving at least 800 Mt of CO₂ per year, equivalent to 2% of the total anthropogenic carbon emissions or 20 times the total carbon emissions of Switzerland (20% of the EU emissions).

The project approaches the development of UGC with a novel and innovative two-fold strategy, moving the field of cement and concrete science far beyond its current state-of-the-art to achieve the ambitious carbon-reduction target:

1. Reduce the amount of clinker in cement substantially below 50% (namely UGCement), maximizing the use of mineral additions such as calcined clay and limestone through a fundamental understanding of reaction kinetics and hydrate precipitation that contributes to reduce porosity.
2. Reduce the amount of binder (hydrated paste) below 250 kg/m³ per cubic meter of concrete, bringing together the knowledge gained on UGCement with the development of novel admixture formulations to tackle this challenge.

This project merges the expertise of Dr. Zunino in advanced cement chemistry, hydration mechanisms and characterization techniques with the knowledge and experience available at the PCBM group on admixture molecular design, characterization and optimization. The synergy of capacities between the Dr. Zunino and Prof. Flatt’s group will enable to effectively tackle the scientific challenges related to this project.
 

Limestone calcined clay cements (LC³)

The climate emergency requires the adoption of strategies and technologies that can effectively reduce the CO₂ emissions in the short to midterm to keep the global temperature rise below 2°C above pre-industrial levels. Concrete is the substance most consumed by humanity after water. Blended cements, in which part of the energy intensive clinker is replaced by supplementary cementitious materials, are by far the most realistic means to obtain large scale CO₂ reductions. LC³, blended cement produced by the combination of limestone, calcined clays and Portland cement provides a solution that achieves equivalent mechanical performance to OPC, better durability against chloride and ASR and a reduction of CO₂ emissions by about 40%. Furthermore, it is cost effective compared to OPC currently on the market, and due to the similarities with OPC it is a material that can be adopted today using the same construction equipment and workforce worldwide.

The LC³ project is internationally led by Prof. Karen Scrivener and her group at EPFL, and Dr. Zunino was actively involved in it during his PhD and PostDoc in the group. Among his contributions, establishing a mechanism of sulfate requirement in blended cements and a detailed description of the microstructural development of LC³ can be considered landmarks of his work. Currently, Dr. Zunino remains active in the LC³ research team, actively participating in education and dissemination activities organized in different regions of the world.

Hydration and phase assemblage of Portland limestone cements (PLC)

During his internship at the National Institute of Standards and Technology (NIST) in the US, Dr. Zunino engaged actively in the projects within the group of Dale Bentz, aimed to develop and optimize PLC for the US market. Limestone, while mostly inert, provides excellent nucleation surfaces for the precipitation of hydrates, and in some cases may positively contribute to the workability of the material. Nowadays, these cements are more common than conventional Type I/II (OPC) Portland cements. Furthermore, the widespread availability of limestone makes these cements ideal candidates for scaling up replacement of clinker beyond what is feasible with just limestone with other locally available materials.
 

LC³ Doctoral School on characterization methods of cementitious materials (EPFL)

Dr. Zunino participates as a lecturer in the doctoral school that is annually organized by the group of Prof. Scrivener at EPFL since 2017. The school receives 40 participants from all over the globe and combine theoretical lectures with practical lab sessions. During the history of the school, it has hosted scholars and industry professionals from more than 35 countries. In 2018, he assumed the organization and coordination of the school, role that he continued to hold until his departure from the group in 2022. Currently, he continues to participate of the school as an invited lecturer.

His lectures within the school are entitled:

- Limestone calcined clay cements (LC³⁾
- Hydration monitoring techniques
- Formulation of low-carbon concrete


Advanced cement characterization methods (ACCM) master course

Dr. Zunino participated as student mentor (until 2022) and currently as invited lecturer of the master course that is annually organized by the group of Prof. Scrivener at EPFL. This course provides students with access to different techniques and their possibilities and limitations for studying cementitious materials. Beyond theory, the students engage in a group project where they need to promote and convince a jury of experts that their technique is the right one for their lab. This offers not only technical knowledge, but also critical analysis abilities of published literature and the work of their peers.