TWO Guest lectures – Net Zero Concrete : Pathways to Sustainable Construction / Low-carbon 3D concrete printing

Monday, October 6 at 2:30 p.m. in GB202

TWO Guest Lectures by

Prof. Chi Sun Poon and Prof. Shipeng Zhang

Net Zero Concrete : Pathways to Sustainable Construction

Chi Sun Poon
Mishael Anson Professor in Civil Engineering
Distinguished Research Professor
Dept of Civil and Environmental Engineering
The Hong Kong Polytechnic University

Abstract
The urgent need to decarbonize the construction sector is driving significant innovation in concrete technology. This presentation explores the forefront of low-carbon concrete development, focusing on integrated strategies to reduce its environmental footprint drastically. Key areas covered in the presentation will include the formulation and application of novel low-carbon cements (such as waste-derived cement and carbonizable cement) and the utilization of carbon-captured supplementary cementitious materials (SCMs), where industrial by-products or novel materials treated with captured CO2 replace high-emission clinker. The advances in low-carbon ultra-high-performance concrete and low-carbon lightweight concrete mixes will also be introduced. The presentation will also highlight CO2 utilization technologies, including direct CO2 mixing, CO2 foaming and accelerated CO2 curing, which permanently mineralize CO2 within the concrete matrix, enhancing early strength while sequestering carbon. This overview demonstrates that a synergistic approach combining advanced materials, carbon capture and utilization (CCU), and innovative processes offers a viable pathway to achieve high-performance, low-carbon concrete for a sustainable built environment.

Prof. Chi Sun Poon is currently the Michael Anson Professor in Civil Engineering and Distinguished Research Professor of the Civil and Environmental Engineering Department of The Hong Kong Polytechnic University.

He specialises in the teaching and research of civil engineering materials, eco-friendly construction materials and waste management. He is a Fellow of the Hong Kong Institution of Engineers and the Hong Kong Concrete Institute. He is a pioneer in the research on valorizing different types of waste as construction materials. His extensive publications in the area make him one of the leading scholars in this field. He has a Google Scholar H-index of >150, and according to metrics compiled by Stanford University, Prof. Poon is listed among the top 2% of the world’s most highly cited scientists in the field of Building & Construction. He was appointed as a Changjiang Scholar Chair Professor by the Ministry of Education of China in 2017, and he was also awarded the State Technological Innovation Award in 2017 (2nd Class).

Low-carbon 3D concrete printing

Prof. Shipeng Zhang
Assistant Professor in Civil Engineering
Dept of Civil and Environmental Engineering
The Hong Kong Polytechnic University

Abstract
In response to labor shortages, an aging workforce, significant waste generation, and low productivity, the construction industry is increasingly embracing digitalization. Within this shift, 3D concrete printing (3DCP) has emerged as a promising solution. Unlike conventional methods, 3DCP uses digital controls to extrude concrete layer by layer, eliminating the need for formwork and significantly reducing construction time, cost, and waste. However, the process demands precise control over the concrete’s rheological properties, often requiring mixes with high cement content. This conflicts with sustainability goals due to the high carbon footprint of Ordinary Portland Cement (OPC). This talk introduces innovative strategies to reduce the embodied carbon of 3DCP by incorporating solid and gaseous wastes. For example, the greenhouse gas CO₂ can act as a rheology modifier, enabling a ‘set-on-demand’ approach that balances pumpability with buildability while ensuring permanent CO₂ sequestration within the printed structure.

Prof. Shipeng Zhang serves as an Assistant Professor in the Department of Civil and Environmental Engineering at The Hong Kong Polytechnic University, concurrently holding the positions of Associate Director of Research Centre for Resources Engineering towards Carbon Neutrality (RCRE) and Deputy Director of the PolyU-NAMI 3D Concrete Robotic Printing Research Centre.

He received his Bachelor of Science degree in Civil Engineering from the University of Minnesota, followed by his Master of Engineering and PhD in Civil Engineering from McGill University. Dr. Zhang is dedicated to addressing pressing environmental challenges through the advancements of sustainable construction materials and technologies. His research focuses on concrete carbonation technology, sustainable cementitious materials, and low-carbon 3D concrete printing. Dr. Zhang has published more than 50 SCI research articles in the top/key journals of his research field, such as Automation in Construction, Composites Part B: Engineering, Cement and Concrete Research, etc. Dr. Zhang has garnered several accolades, such as the Hong Kong Research Grants Council Early Career Award, Graduate Excellence Fellowship award, Les Vadasz Engineering Fellowship, and McGill Engineering Doctoral Award.