Waste reduction final report -4 - Test Input

It is recognized that lean concrete will be the place for recycled mixed aggregates. It can be
introduced at many places on the construction site without problems. Examples for this (and
for other types of recycling concrete, too) are given in two brochures by the canton of Geneva
[GE 2009]. In order to transfer the current knowledge to the regarding persons and to
overcome prejudices, the project “gravel for generations” has been started.
Another discussion point concerns possible pollutants in mixed mineral material and their
behaviour. In Switzerland, a study was accomplished about pollutants in secondary
construction material in general [VSS 2002].
Secondary construction materials do not contain many pollutants; additionally, most of them
are inorganic. Indeed, concentrations of chemicals are higher in recycled mixed aggregates
than in other secondary materials. The authors claim that high quality requirements for all
secondary materials would ensure security for human beings and the environment. This way,
accumulation of pollutants such as nitrogen compounds or chromium in ground water is
avoided.
Asphalt
About 50% of asphalt waste is used directly on site, e.g. by a procedure using heat; the other
50% are recycled into recycled asphalt aggregates or landfilled. However, there are hold
some discussions about the recycling of asphalt: A total of about 6 MT pavements contains
tar, which corresponds to about 5% of the total embedded asphalt [ARV 2008]. Abrasion
of material comprising PAH can trigger health problems.
Today, materials with more than 20,000 mg PAH per kg binding agent are allowed only to be
used with restrictions and current policy works suggests to sort out and eliminate the tarcontaining
fraction [FOEN 2008c]. In contrast to this, the industry claims that there exist
methods for a safe reuse of these materials [Killer 2008]. Even so, the next revision of the
ChemRRV will probably implicate a prohibition of new bitumen containing road surfaces
and PAK parts in the upper layers of roads [Stadt Zürich 2007]. The binding material shall be
taken out of the cycle by incineration.
Excavation material
Excavation material is generated in high amounts, contaminated (only 5-10%) or pollutionfree.
As there is no obligation to capture the amount, only estimations can serve as lead.
Today, estimations give figures around 40 to 60 Mm 3 per year, and given that big projects
and high construction activity are expected, this figure will rise in the next years. Today, the
material is mainly used for backfilling or reclamation of gravel pits or construction sites. The
remaining parts are used in another form or are landfilled.
Depending on the canton’s space availabilities, scarcity of landfill space will become an
urgent problem. Today already, materials are transported over big distances with lorries. The
current TVA revision will deal with this problem. Materials with good construction
properties can be used as construction materials, but for the remaining parts, solutions for insitu
or other use of excavation have to be established. A study accomplished by the
Hochschule für Technik, Rapperswil was ordered by the FOEN [FOEN 2008b]. The study
compiled examples of sustainable in-situ use of excavation materials in landscape forming.
Identified problems concerned the quality of the remaining excavation material, space
constraints and interim storage. Furthermore, it concluded that it was easier to reuse
excavation material at big construction sites than at smaller ones. From the economic side of
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