3 Guidelines for Effective and Sustainable Recycling
of Construction and Demolition Waste
Serena Giorgi presented an analysis of actual re-use and recyling practices in
European countries [2]. Starting from a screening of current percentage of reuse and
recycling, types of waste and recycling destinations, as well as incentive policies in
member states of European Union-28, she explained that the objective of the
directive 2008/98/EC on waste that imposes a minimum of 70% re-use or recycling
by weight within 2020, can be easily reached or even already achieved by more
than half of European countries. Research data of the average material composition
of CDW percentage shows that 60–70% (by weight) is composed of concrete and
masonry, followed by minor percentages of asphalt, wood, metal, gypsum and
plastic. Aggregates are therefore the largest amount of CDW. Based on these facts
Serena Giorgi reported that since the Directive 2008/98/CE expresses the objective
in percentage of weight, it doesn’t value the best material to be recycled in terms of
effectiveness and sustainability (e.g. recycling of plastic parts in Italy is only 21%),
but heavier ones. Also she argued that there isn’t any assessment of the “quality” of
recovery, i.e. differentiation between reuse, upcycling/downcycling or energy
recovery. In this way, it was found that in many countries, aggregates are mainly
recycled for road foundations, earth works and backfilling. A further issue is the
assessment of the effectiveness of recycling sustainability, especially for inert
waste. A study of the ecological balance of the concrete produced with recycled
aggregates shows that there is a sharp increase of environmental impact, first due to
the increase of cement content used with recycled aggregates and second due to the
transport from supply points to the production facilities. Finally the speaker defined
ways to improve legislation and proposed some guidelines, aimed at making the
recycling of CDW management more effective and sustainable through Life Cycle
Management.
4 Adaptive Reuse of Buildings and Its Life Cycle
Sustainability Benefits
Harn Wei Kua then presented a case study of primary school refurbishment
strategies in Singapore, based on a life cycle based approach [3]. The environmental
and economic assessment was performed for alternate designs for school buildings,
aiming at reducing the need or extent of future renovations and demolitions. This
analysis lead to design guidelines, in which alternate designs are compared in terms
of potential net amount of C&D wastes that could be saved as well as net decrease
in life cycle impacts and resources requirements. Also, for each alternate design, the
potential of each kind of generated C&D wastes for recycling or reuse, and the life
cycle costs of the buildings were estimated, as well as the social and cultural effects
of building preservation based on similar projects elsewhere in Singapore.
Management of Construction Waste: LCA …
207
of Construction and Demolition Waste
Serena Giorgi presented an analysis of actual re-use and recyling practices in
European countries [2]. Starting from a screening of current percentage of reuse and
recycling, types of waste and recycling destinations, as well as incentive policies in
member states of European Union-28, she explained that the objective of the
directive 2008/98/EC on waste that imposes a minimum of 70% re-use or recycling
by weight within 2020, can be easily reached or even already achieved by more
than half of European countries. Research data of the average material composition
of CDW percentage shows that 60–70% (by weight) is composed of concrete and
masonry, followed by minor percentages of asphalt, wood, metal, gypsum and
plastic. Aggregates are therefore the largest amount of CDW. Based on these facts
Serena Giorgi reported that since the Directive 2008/98/CE expresses the objective
in percentage of weight, it doesn’t value the best material to be recycled in terms of
effectiveness and sustainability (e.g. recycling of plastic parts in Italy is only 21%),
but heavier ones. Also she argued that there isn’t any assessment of the “quality” of
recovery, i.e. differentiation between reuse, upcycling/downcycling or energy
recovery. In this way, it was found that in many countries, aggregates are mainly
recycled for road foundations, earth works and backfilling. A further issue is the
assessment of the effectiveness of recycling sustainability, especially for inert
waste. A study of the ecological balance of the concrete produced with recycled
aggregates shows that there is a sharp increase of environmental impact, first due to
the increase of cement content used with recycled aggregates and second due to the
transport from supply points to the production facilities. Finally the speaker defined
ways to improve legislation and proposed some guidelines, aimed at making the
recycling of CDW management more effective and sustainable through Life Cycle
Management.
4 Adaptive Reuse of Buildings and Its Life Cycle
Sustainability Benefits
Harn Wei Kua then presented a case study of primary school refurbishment
strategies in Singapore, based on a life cycle based approach [3]. The environmental
and economic assessment was performed for alternate designs for school buildings,
aiming at reducing the need or extent of future renovations and demolitions. This
analysis lead to design guidelines, in which alternate designs are compared in terms
of potential net amount of C&D wastes that could be saved as well as net decrease
in life cycle impacts and resources requirements. Also, for each alternate design, the
potential of each kind of generated C&D wastes for recycling or reuse, and the life
cycle costs of the buildings were estimated, as well as the social and cultural effects
of building preservation based on similar projects elsewhere in Singapore.
Management of Construction Waste: LCA …
207