Guest Lecture

Title: Sustainable approaches to the production of construction materials: from the Earth to the Moon (and beyond)

By Prof. Luca Valentini, Ph.D

Department of Geosciences, University of Padova

Venue: Theater 4, Engineering Complex, Meru University of Science & Technology, Kenya
Date: 26th October, 2022
Time: 1400 hours EAT
For inquiries, contact: materialsproject@must.ac.ke
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Luca Valentini is an Associate Professor at the University of Padua, Italy. He obtained a PhD in Earth Sciences at the National University of Ireland Galway and won the prize for best PhD thesis, awarded by the Italian Society of Mineralogy and Petrology (SIMP). His expertise and research interests lie at the intersection between applied mineralogy, materials science and physical chemistry, and he combines experimental and numerical methods to assess the role of small-scale physical and chemical processes in determining the engineering properties of cement-based materials. He published over 50 peer-reviewed publications and acted as guest editor for the journals Elements and Frontiers in Materials. He currently collaborates with several institutions based in the African continent on the use of calcined clays for sustainable construction and is the local coordinator of the Erasmus+ mobility agreement between University of Padua and Meru University of Science and Technology (Kenya). As part of this agreement, he co-organized the online workshop “Global Partnership for Sustainable Construction and Resource Efficiency”, attended by over 250 participants distributed in 41 countries. He also participated in several organizing and scientific committees in international conferences. He is the co-founder of Opigeo, a spinoff of the University of Padua committed to the implementation of circular economy approaches to innovative building and construction solutions. He is an active member of the RILEM TCs on Calcined Clays as Supplementary Cementitious Materials and on Carbonation of concrete with supplementary cementitious materials.

Abstract

Although the ongoing discussion on cement and concrete sustainability is mostly focused on CO2 emissions, the management of raw materials used for construction also deserves the attention of the scientific community and industry. Each year, the construction and building sector incorporates about 40% of the over 90 billion tonnes of raw materials extracted from the Earth’s spheres. Raw materials supply chains can be exposed to risks of critical shortages and price volatility (e.g. associated with changing geopolitical scenarios), and their transport over long distances strongly contributes to the overall anthropogenic CO2 emissions. Therefore, deploying strategies aimed at mitigating the impact of raw materials supply, in line with what envisaged by Sustainable Development Goal 12 (sdgs.un.org/goals/goal12) will be crucial to the achievement of a sustainable construction industry. In such a context, clays are emerging as a key raw material for alternative cement, given their abundance, homogeneous geographical distribution and relatively low cost. This lecture will focus on the use of locally sourced clays, including laterites, for the production of both blended and OPC-free cements. The use of other alternative, locally available raw materials (industrial and agricultural by-products, carbonaceous shells, marls etc.) will also be explored, with the aim of assessing both the environmental and engineering performance of binders incorporating such locally sourced primary and secondary resources. Some specific scenarios will be addressed: this will include the African continent, as well as current strategies for future construction in an extra-terrestrial environment, based on the ISRU (in situ resource utilization) approach. Implications about possible lessons to be learned from the ISRU paradigm, back on planet Earth, will be discussed.