Production of cement and fibre results in high emissions of CO2. Hence, UHPC should be used where the special material properties are utilised to such an extent that the overall material consumption and environmental impact for a structure are reduced.
Ingrid Lande will defend the thesis Approaches and Strategy Development Towards More Sustainable Ultra-High-Performance Concrete (UHPC) for the PhD degree, 25 May 2023.
The PhD project was part of the research project 'More Efficient and Environmentally friendly Road Construction' (MEERC) partly funded by the Research Council of Norway and Sørlandets Kompetansefond. The project was started in collaboration with Nye Veier, in addition to other academic institutions and industrial partners.
Concrete is the most widely used building and construction material in the world. It is crucial for the wealth and growth of nations at all developmental stages. The high consumption leads to considerable CO2 emissions and resource demand. Actions are required to establish a more sustainable concrete industry. One approach that is not yet fully utilised is the use of ultra-high-performance concrete (UHPC) (Fig. 1).
UHPC is a relatively new fibre-reinforced concrete material with higher strength and durability compared to normal concrete. These material properties are achieved, among other things, through a high content of cement and micro fibres made from high-strength steel. Production of cement and fibre results in high emissions of CO2. Hence, UHPC should be used where the special material properties are utilised to such an extent that the overall material consumption and environmental impact for a structure are reduced. One promising application area is bridge rehabilitation, which has been documented to be both economically and environmentally beneficial.
The research presented in the thesis focuses on reducing the environmental impact of UHPC and developing a strategy for how UHPC can be used more sustainably.
Several approaches to reduce the environmental impact of UHPC were investigated. More efficient use of cement and high-strength steel fibres are two of the main areas of the thesis. A third part of the work was to investigate the potential for local production of UHPC. These investigations included analysis of results obtained from both literature reviews and experimental studies.
The last part was the development and proposal for an overall strategy on how the development and use of UHPC can contribute to reducing the environmental challenges of the concrete industry.