This report focuses on how to use residual aggregates from selected danish quarries.
It is estimated, that around 15% of all dugged-up produce of sand, gravel, clay and
stone in quarries are returned to the pits, due to them not meeting the requirements
established by the industry. With regard to the promise of an increase in aggregate
consumption and the decreasing availability which Denmark faces in the not-toodistant
future, it is becoming an increasingly important necessity to utilise the
natural aggregates in a more local and efficient way.
Interviews have been conducted with a local governing body, and local quarry owners
and managers, to understand and map different point-of-views in the quarrying
industry.
To understand why the aggregates are disposed of and to find an industrial use
for them, seven types of the disposed products from three different suppliers have
been acquired to undergo four experiments in laboratory: Visual identification,
water content analysis, sieve analysis and compression strength of concrete with
the products used as aggregrate. The results from the experiments are hereafter
compared to the danish versions of European Standards regarding aggregates for
concrete, mortar, unbound mixtures, and bituminous and hydraulically bound
mixtures for use in road constructions and surface treatments.
The results and comparisons have shown, that only one of the residual aggregates
complies with the European Standard regarding aggregates for concrete. The
remaining six aggregates do not comply with the standards, mainly due to the
particle size distribution. Therefore, this report recommends a platform for quarry
actors for facilitating the selling and buying of residual aggregates internally, so that
residual aggregates from different quarries can be mixed to alter the particle size
distribution to comply with the standards.
Lastly, questions are raised to the imminent lack of ressources and the handling
hereof, and solutions proposed by the interviewees and found through the literature
search are being discussed to showcase the different perspectives on the matter.