Yiannis Pontikes
KU Leuven
Yiannis Pontikes is a BOF-ZAP associate professor at the Department of Materials Engineering, KU Leuven. He is leading the Secondary Resources for Engineered Material (SREMat) research group, that consists of approximately 15 post-doctoral and post-graduate researchers. SREMat has built an expertise on the valorisation of residues towards ceramic, cement and inorganic polymer (geopolymer) formulations, from the level of binder synthesis all the way to full scale prototypes. Yiannis has been a co-author in >60 peer-reviewed journal papers, he is currently work package leader or project coordinator in 12 national and international projects and is participating in different fora and networks (SIM2 at KU Leuven, CR3 in USA…). He is one of the founders of the Journal of Sustainable Metallurgy, where he serves as the managing editor.
The development of alternative cementitious binders has been primarily fuelled by the need to reduce the environmental footprint of ordinary Portland cement (OPC). A wide range of approaches and options have been proposed, some already being explored at pilot-plant scales. A thoughtful approach would, however, acknowledge that OPC production is already incorporating a number of residues, and the same is true for most of the blended-cement formulations. Moreover, it would be reasonable to expect that these new binders-to-come, should be on one hand better in terms of environmental footprint, but on the other hand, at least comparable in terms of performance and availability to society. The latter, in engineering terms, translates into a production process that is relatively easy to erect, technically and financially, and robust during operation. Moreover, the binder itself should be composed of abundant elements, so as to empower construction and growth for all. The most abundant elements in the earth’s crust are oxygen, silicon, aluminum, iron, calcium, and sodium. Assuming a high-temperature process is employed, then the parent mineral where these elements are present is of little interest: they will all melt, and by adjusting the chemistry and the cooling conditions, the solidified product will be the glass precursor to be used as the cementitious binder thereafter. The high-temperature process is also contributing to the “binder-for-all” aspiration.
Considering the above framework of principles, this work is describing the production process of these binders from virgin raw materials, the existing-today industrial residues that behave similarly, and the two lines of binders that have been developed over the past years, one with OPC and the other without. The data to be presented refer to both laboratory work and pilot-plant scale at industrial facilities and extend from mortar formulations to ultra-high strength concrete. Calculations on the environmental footprint are also provided. The work concludes by presenting an overview of the on-going activities.
