Construction and demolition waste represent 31% of the total waste generation in the European Union, which corresponds to 900 million tons each year, and concrete accounts for 25% of the total amount of waste materials from the construction industry. These are vast amounts. In Denmark 90% of the Danish concrete waste deriving from demolition is reused as fill, mainly as base layer or road-fill. However, recycling concrete aggregates (RCA) in new concrete instead can help alleviate the resource challenges around big growing cities.
Recycling concrete aggregates in new concrete, as its scientific effort is aimed at material reuse to help creating more value to an otherwise end-of-life product and enhancing resource efficiency: reuse of concrete aggregatres. So far the innovative full-scale projects in Denmark have only used the coarse fraction 4-25mm. However, when crushing concrete 40-60% is in the 0-4mm fraction.
The purpose of this PhD project is to identify problems and potentials for RCA relative to utilisation as replacement of natural aggregates in concrete production, based on life cycle assessment, the characteristics and development of a new methodology for testing water absorption of 0-4mm RCA. This will allow RCA being considered a resource for all fractions 0-25mm. This will make it possible to optimise the usage of natural resources and accommodate resource scarcity.
Supervisors: Lisbeth M. Ottosen (DTU Byg), Mette R. Geiker (NTNU), Morten Birkved (SDU).
More about the project and the collaborations:
http://reader.livedition.dk/danskbyggeri/1009645866/html5/14/
https://www.licitationen.dk/article/view/645176/universitet_saetter_spot_pa_genbrug_af_beton