NUS-CityU Joint Seminar (In-class and Via Zoom)

Waste-derived resilience and sustainable development in smart city

by

Dr. Guoqing GENG, Dr. Guoyang LU, Dr. Hongjian DU, and Dr. Xiangping XIAN 

Dr. Guoqing GENG: Assistant Professor, Department of Civil and Environmental Engineering, National University of Singapore

E-mail: ceegg@nus.edu.sg

Dr. Guoyang LU: Assistant Professor, Department of Architecture and Civil Engineering, City University of Hong Kong

E-mail: guoyanlu@cityu.edu.hk

Dr. Hongjian DU: Senior Lecturer, Department of Civil and Environmental Engineering, National University of Singapore

E-mail: ceedhj@nus.edu.sg

Dr. Xiangping XIAN: Assistant Professor, Department of Architecture and Civil Engineering, City University of Hong Kong

E-mail: xiangping.xian@cityu.edu.hk

Date: 05 February 2025, Wednesday

Time: 15:00 - 17:00 (Hong Kong Time) 

Venue: LI 2415, Li Dak Sum Yip Yio Chin A Bldg

Language: English

Enquiry: Prof. Xiangping XIAN (Tel: 3442 8704)

Zoom Link: Https://cityu.zoom.us/j/85274159226?pwd=V3BBewtqwdi3You6wvvHR4KGTkdnjI.1 

Meeting No.: 852 7415 9226

Password: 123456

Title: Sustainable alternative binders made from waste in Singapore (Dr. Guoqing GENG)

Abstract (Dr. Guoqing GENG)

Ordinary portland cement (OPC) is the primary binding material for modern construction, yet it has the most embodied carbon among all concrete constituents. There is an urgent need to find supplementary cementitious materials (SCMs) that are widely available, with equal or better performance than OPC but much lower carbon footprint. Meanwhile, the lack of natural resources is a constant threat to the sustainable develop of Singapore. There are local low-grade/waste materials that can potentially be used for construction if properly treated. Dr. Geng’ talk, titled ‘Sustainable Concreting with Waste and Low-grade Material’, will share several solutions developed by his team in NUS, on how to use waste material to create high performance construction materials. For example, the municipal waste incineration ash can be used as a strength contributing constituent when mixed with Al-rich materials. The construction waste can absorb flue-gas CO2 to become a reactive SCM. These solutions may inspire pathways to a circular economy of construction in Singapore.

ABOUT THE SPEAKER (Dr. Guoqing GENG)

Dr. Geng received his Doctoral degree in CEE of UC Berkeley in 2017. His PhD work focused on the microscale chemistry of modern construction materials. He was awarded a postdoctoral fellowship in Paul Scherrer Institute (Switzerland), where he studied the durability of concrete both as a construction material and hosting material for radioactive waste. He joined the department of CEE in NUS in 2019. Since then, he has been leading a research group focusing on sustainability and performance-based designing of modern construction material. Currently he is a board member of ACI-Singapore Chapter, of Singapore Concrete Institute, and the convener of East Asia for RILEM.

Title: Future road infrastructure for resilient and smart city (Dr.  Guoyang LU)

Abstract (Dr. Guoyang LU)

The mobility of the future requires innovative solutions in terms of physical and virtual transport infrastructures. As a major part of transportation infrastructure, pavements are expected not only to carry more traffic load (longer durability), but also to provide additional sustainable functions (permeability, noise reduction and low emission and energy conservation) and intelligent features (structural health monitoring, energy harvesting, as well as real-time traffic monitoring) for the development of resilient and smart city. The incorporation of advanced technologies in both pavement materials and structure are required to fulfill the multiple functions. For instance: i) durability of pavement can be enhanced by the optimization of mix design and construction approaches of pavement materials. Additionally, it is also addressed that the use of polymer materials, methods of mix analysis and cracking models, coupled with specific construction techniques that can also significantly increase the life of the asphalt pavement; ii) the sustainable functions can be normally obtained by applying low temperature mixing technology and solid wastes in pavement materials production to help reduce carbon dioxide emissions for achieving carbon neutrality. To facilitate more environmental benefits, pavement materials can be also designed to be porous to facilitate runoff permeability and traffic noise absorption; iii) the intelligent features of pavement can be achieved with the help of embedded ‘smart’ sensors and/or advanced materials with sensing and energy storage capabilities. These characteristics can be recorded with high spatial and temporal accuracy catering for future mobility (intelligent transportation systems, autonomous driving, and non- destructive detection, etc.). As one of the most densely populated cities in the world, Hong Kong is grappling with growing congestion, overcrowded transport, and environmental pollution. More durable, sustainable and intelligent road infrastructures and technologies are desired to further improve the efficiency of traffic management, the overall capacity of the road system, transportation safety and connectivity, and reduce the energy consumptions and emissions. Based on these motivations, Dr. Lu will discuss the recent advances and future trends in pavement engineering.

ABOUT THE SPEAKER (Dr. Guoyang LU)

Dr. Lu received bachelor degree in Highway Engineering from Southeast University (China, 2013), master degree in Structural Engineering from the University of Sheffield (UK, 2015), and PhD degree in Highway Engineering from RWTH Aachen University (Germany, 2019). His research interests mainly include intelligent transportation infrastructural materials and technologies, simulation of pavement structures and materials, and non-destructive evaluation of transportation infrastructure. Dr. Lu has published over 70 SCI journal papers (Google Scholar h-index: 22), and has received various research awards, such as the Best Paper Award of 2021 Transportation Research Congress (TRC), Outstanding Service Award of 2020 Academy of Pavement Science and Engineering (APSE). Dr. Lu currently serves as the secretary of the American Society of Civil Engineers (ASCE) Greater China Section, the secretary of the Asphalt Pavement Discipline of the World Transportation Convention (WTC) Scientific Committee, and he also serves as an Associate Editor of the Journal of Cleaner Production.

Title: Innovating Sustainability Education in Civil Engineering through Design Competitions (Dr.  Hongjian DU)

Abstract (Dr. Hongjian DU)

This talk explores an innovative teaching approach that integrates sustainability into structural engineering education through a transformative design competition. Drawing from experiences at the National University of Singapore, students in Structural Concrete Design were challenged to develop the structural frame for Singapore’s first net-zero building. The hands-on competition not only enhanced student engagement and performance but also deepened their understanding of sustainability in engineering. The initiative’s success has led to its adoption across other courses and recognition in external competitions. Looking ahead, this approach aims to foster global collaboration in advancing structural engineering education, equipping future engineers to tackle pressing sustainability challenges.

ABOUT THE SPEAKER (Dr. Hongjian DU)

Dr. Du Hongjian is a dedicated educator known for his innovative use of competition-based learning to teach sustainability, which has led to positive learning outcomes. He was honoured with the prestigious Excellence in Structural Engineering Education Award by the Institution of Structural Engineers (UK) in 2024 and named an ExCEEd Teaching Fellow by the American Society of Civil Engineers in 2023. His teaching excellence has also been recognized with the NUS Annual Teaching Award in 2023 and 2024, as well as the NUS Provost Young Educator Award in 2020. Dr. Du is an expert in concrete materials and structures, focusing on low-carbon construction materials and 3D concrete printing for sustainable urban development. His research has influenced both the local industry and the global community. His achievements include being listed among the Top 2% Scientists by Stanford University and receiving the Outstanding Paper Award from Materials and Structures in 2022, as well as the Excellence Award from the Singapore Concrete Institute in 2022 and 2024.

Title: A holistic system converting waste into value-added construction materials via carbonation (Dr.  Xiangping XIAN)

Abstract (Dr. Xiangping XIAN)

Concrete is the most commonly used man-made construction material and ordinary Portland cement (OPC) has been used as the primary cementitious material for decades. However, the cement and concrete industries contribute to more than 8 % of the total global CO2 emissions. On the other hand, Hong Kong is under enormous pressure to deal with its waste and achieve carbon neutralization targets. Therefore, this presentation will briefly talk about applying carbonation curing technique to convert waste materials including steel slag, recycled concrete waste, waste glass, plastic waste, and municipal solid waste incineration ash into valuable construction materials through early-age carbonation, which can not only improve the concrete properties but also capture CO2 inside, making contributions to environmental protection and sustainable development in Hong Kong.

ABOUT THE SPEAKER (Dr. Xiangping XIAN)

Dr. Xiangping XIAN attained his Master's degree and Ph.D. in Civil Engineering from McGill University in May 2017 and February 2021 respectively. In 2023, he was also one of the Marie Sklodowska-Curie Future Roads Fellow recipients from Cambridge University. Before joining the Department of Architecture and Civil Engineering (ACE) at CityU in August 2023, he worked as a full-time postdoctoral researcher at McGill University for more than 2 years. In the meantime, he was also a part-time postdoctoral Research Associcate at the University of Toronto. Dr. Xian's research is mainly about producing green and functional cement-based products made from OPC, industrial waste (i.e., steel slag), municipal solid waste incineration (MSWI) residues, concrete waste, etc., through Carbon, Capture, Utilization, and Storage (CCUS) aiming to make contributions to both environmental protection and sustainable development. Currently, he also serves on the Technical Committees for both Code for Practice for Structure Use of Concrete and Code for Practice for Dead and Imposed Loads under the Building Department in Hong Kong, and for the Asian Concrete Federation (ACF). He also works as the Deputy Principal at the Bright Future Engineering Talent Hub of the City University of Hong Kong and is a Fellow of the Hong Kong Concrete Institute.