Widevision 2024 | Western Sydney University

Krishna is a second-year doctoral researcher from the School of Engineering, Design and Built Environment who has been researching on the utilisation of different waste and local clay varieties in Australia. His goal is to use these clays to develop economical limestone-calcined clay cement (LC3) which aids in carbon mineralisation and hence reduces cement carbon emissions. He has been awarded the Australian Government (Research Training Program) Scholarship for Higher Degree Research and has also been supported through the CSIRO Top-up scholarship. Krishna is currently working under the supervision of Dr. Cheng (Jason) Jiang and Professor Zhong Tao. He is a published author of around 29 publications including journal articles, conference proceedings and book chapters.

Global cement production accounts for 7-8% of CO2 emissions worldwide. Most countries are heavily dependent on the utilisation of cement to meet increasing construction material needs. The production of cement is the major contributor to CO2 emissions in the construction industry. To reduce emissions, the adoption of supplementary cementitious materials (SCMs), such as fly ash and slag, is essential. However, they are gradually becoming scarce due to the transition from fossil fuels to renewables to the country's commitments towards sustainability. Calcined clays as SCMs provide a sustainable alternative with potentially limitless reserves. The utilisation of calcined clays to replace part of cement can significantly reduce CO2 emissions. Limestone-calcined-clay-cement (LC3) uses locally available clay sources to reduce CO2 emissions by up to 40%, with cement replacement rates of about 50%. The necessity for higher kaolinite content in the clays produces significant challenges in kaolin-scarce regions such as Australia. Therefore, the experimental studies of this research project is focused on investigating the feasibility of substituting high-grade kaolin with low-grade kaolin clays as well as non-kaolin clays, which are abundant in Australia, and assessing their suitability through different tests to optimise the resulting performance and associated costs. The findings of this research will underscore the potential of employing low-grade clays in the form of sustainable raw materials for the development of LC3 composites with higher cement replacement rates in Australia. Besides, by leveraging locally available resources, this research study endorses a significant reduction in the carbon footprint of cement production and yields a viable pathway for the construction industry in Australia to transition towards more sustainable practices.

Reena Sanjay Krishna

Development of Economic Low-Grade clay-based LC3 Composites for Construction Applications

Acknowledgement of Country