COWI A/S is an international consulting group, specialising in engineering, environmental science and economics, with headquarters in Lyngby, Denmark.It has been involved in more than 50,000 projects in 175 countries and has approximately 7,300 employees, including engineers, biologists, geologists, economists, surveyors, anthropologists, sociologists and architects.
Circular economy (CE), particularly closed-loop recycling, has been identified as a strategy to enhance the sustainability of the cement industry. The chemical composition of the raw meal - the raw materials used to produce cement - is a limiting factor in cement manufacturing, particularly for CE and end-of-life (EOL) concrete recycling. Cement closed-loop recycling entails retrieving ultrafine concrete waste particles (UFCWP, particle fraction between 0 and 0.25 mm) from EOL concrete using advanced recycling technologies that could replace clinker raw meal in cement clinker manufacturing. Utilizing a combined conceptual stoichiometry mass balance model with material flow analysis for the first time, this study demonstrates the chemical limitations of substituting raw materials with ultrafine EOL concrete in a closed-loop recycling process within the Danish clinker production. The main results indicate that a maximum of 11.76% UFCWP can be used to replace conventional raw meal in Danish cement clinker production, resulting in a 10% reduction in global warming potential compared to conventional cement clinker production. For this, we would require three times more EOL CEM I concrete in Denmark than is currently produced (approx 1.2 Mton). This study highlights the mismatch between current cement demand and EOL concrete for closed-loop recycling in Denmark.
This paper demonstrates the implementation of digital workflows in the Mandalselva Bridge project, highlighting their role in facilitating automatic updates and enabling parallel engineering processes. The workflows integrate FEA model results, local design, and BIM modeling to enhance coordination and efficiency throughout the project.
The paper describes the conceptual design of a bridge connecting the island of Tjøme and mainland Norway. The bridge is located 80 km south of Oslo and spans the fjord Vestfjorden. Two bridge types were investigated during the conceptual design: A multi-span composite bridge and a suspension bridge. Complex foundation conditions in the fjord with a thick layer of soft soil required long piles for the composite bridge. Together with a significant loading to the piers from ship impact it meant that the suspension bridge was preferred. However, a very complex topography at the one side of the fjord resulted in challenges in anchoring the main cables. The complex topography was handled by developing a 490m long span suspension bridge with mono-towers, a bridge deck splitting in the ends and spatial main cables in the main span that unified into a single main cable over the tower saddles, anchoring only one single main cable.
The paper presents the development of a simplified analytical modelAnalytical model for wind-induced overturning of high-sided vehicles on bridges and supporting wind tunnel testsWind tunnel test. It is found that vehicles are subject to increased overturning risk due to increased turbulenceTurbulence and vortex shedding developing in the wake region of the towers and that local wind screens can mitigate this effect.
