Cement, the ‘glue’ in concrete, is the durable, waterproof and ubiquitous material upon which modern civilisation is built. Concrete is second only to water in terms of commodity use, and the world produces more than 10 billion tonnes of it each year.
Cement production alone (excluding other aspects of construction) accounts for around 8% of global CO₂ emissions, about half of which results from chemical reactions inherent in the clinker production process. As other industries such as energy and agriculture reduce their share of emissions, cement production may account for nearly a quarter of all human-driven CO₂ emissions by 2050.
Supplementary cementitious materials (SCM) are used in modern cement formulations to reduce the clinker content and hence reduce associated CO 2 emissions, as well as improve performance.
Key examples are limestone calcined clay cements (LC 3), and alkali-activated cements, both of which are produced primarily from naturally abundant minerals such as limestone, clays, or industrial by-products such as metallurgical slags, further enhancing their sustainability.
However, as SCMs often exhibit variable chemical and physical characteristics, inclusion of SCM’s in modern cement formulations results in significant changes in the chemical reaction mechanisms and kinetics, and the resultant evolution of phase assemblage and structure at the nano and micro scale, which ultimately dictate mechanical performance. These changes, as well as those induced by durability phenomena such as carbonation, occur primarily at the nanoscale, but have to date been very difficult to study. A detailed understanding of the phase and nanostructural development in modern cements formulated with SCMs is therefore urgently required, to enable quality control and make them practical for use in large-scale construction.
This PhD uses advanced spectroscopic approaches to understand nanostructural development and phase evolution in modern cements formulated with SCMs, and identify which are the key physical and chemical characteristics of SCMs that influence nanostructrual development in these cements. It will use advanced spectroscopic approaches such as solid-state nuclear magnetic resonance spectroscopy, X-ray absorption spectroscopy, and infrared spectroscopy, including experiments to study reaction and nanostructural development in situ. This will be complemented by other experimental approaches to study cement reaction mechanisms and kinetics.
This will enable optimisation of modern cement formulations, and help to decarbonise cement production.
Based in the School of Chemical, Materials, and Biological Engineering, the successful candidate will be joining a team of multidisciplinary researchers at The University of Sheffield to develop research and innovation for decarbonisation. The successful applicant will join the Sustainable Materials at Sheffield research team. They will benefit from being a member of a friendly and collegial group with world-leading expertise and facilities.
About the research team:
The Sustainable Materials at Sheffield (SMASH) group is a world-leading research team based in a highly-rated and very successful School, building from over 100 years of history in cements research at Sheffield. We investigate interesting and important cements and related materials for applications in construction and nuclear sectors, publish our work in the leading journals and conferences in the field, and take great pride in the fact that alumni have gone on to the highest levels of success in both academia and industry. The School of Chemical, Materials, and Biological Engineering ranks among the top in the UK, and has among the highest levels of research income.
About the primary supervisor:
Dr Brant Walkley is Senior Lecturer in Chemical Engineering at The University of Sheffield, and has made significant contributions to cement materials chemistry and engineering. He has unique expertise in formulation development and advanced characterisation of cements and related materials, particularly in spectroscopic and microstructural techniques exploring the effect of raw material powder characteristics and physical properties of cements in both the fresh and hardened state.
Brant currently leads the Sustainable Materials at Sheffield team, which is a friendly group of 14 PhD and 4 postdoctoral researchers. He is passionate about fostering excellence in postgraduate research, and is currently School PGR Lead, leading on PhD research strategy at both School and Faculty level. Brant has been awarded the ‘Outstanding PGR Supervision Award’ from The University of Sheffield for three years running, in 2022, 2023, and 2024.
How to apply:
Applicants should have a minimum of an upper second class honours degree in chemical engineering, chemistry, bioscience or a related technical subject. If English is not your first language then you must have an International English Language Testing System (IELTS) average of 6.5 or above with at least 6.0 in each component, or equivalent. Please see this link for further information: https://www.sheffield.ac.uk/postgraduate/phd/apply/english-language.
Please see this link for information on how to apply: https://www.sheffield.ac.uk/cbe/postgraduate/phd/how-apply. Please include the name of your proposed supervisor and the title of the PhD project within your application.
