Re-Using Waste as Secondary Raw Material …
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and treatment of waste and production of concrete products). In particular, the team
included: Unibloc s.r.l. (operating in the sector of concrete vibro-compressed components, responsible for the research was arch. Riccardo Cecconi) as group leader
and supported by Assobeton; S.A.M. Engineering S.p.A. (construction company
also operating in the production of prefabricated concrete panels, responsible for
the research was engineer Tiberio Pochini); La RevetVetri s.r.l. (operating in the
separate collection of urban waste, responsible for the research was engineer Massimo Ravagnani); DiDA—Dipartimento di Architettura of Università degli Studi di
Firenze (scientific partner, responsible for the research was Alessandro Ubertazzi
with Benedetta Terenzi); ABC department—Architecture, Built environment and
Construction Engineering of Politecnico di Milano (scientific partner, responsible
for the research was Andrea Tartaglia).
The idea was to transform a waste normally disposed of in landfills into a “new”
raw material. Moreover, the reuse for construction components had to be conceived
by verifying its environmental compatibility, technical feasibility and economic sustainability.
The first step was therefore to identify how and in what to “transform” the waste
from glass recycling. Thanks to the support from Enrico Bernardo and the alternative
production processes designed by him, the use of the waste for the production of foam
glass was identified as the best solution
4 (Table 1). This is a product already widely
used in the construction sector in Northern Europe especially as an aggregate in
concrete mixtures. The significant advantages related to the processes proposed by
the “Ethical concrete” study are primarily:
– The use of waste and not of new resources and components saving the use of a
huge amount of non-renewable resources;
– A production process that requires lower temperatures compared to the typical
process that starts from new raw materials, this means a reduction in the quantity
of energy involved in production;
– The normal presence of organic elements in the waste that allows the activation
of the foaming process without the use of additives, with a further advantage over
the use of resources.
4 To obtain this result “several alternatives have been tested for the waste glass processing in order
to achieve an adequate glass sand that can undergo the necessary heat treatment to obtain foam
glass. As a consequence of this effort, a virtuous circle has started with the ambitious goal of giving
dignity to a new material from a waste product which currently is simply disposed of in dumps. A
series of samples with slightly different physical–chemical characteristics have been produced with
tests run by the researchers, according to the procedures used in the thermal process to obtain the
material set by prof. Bernardo. By comparing the different properties of the foam glass samples
obtained, the partners of this project have identified as the most interesting material, according to
the set goals, the one with the best ratio between compressive strength and density, therefore, with the
best specific resistance. This is because the aggregates are not particularly light but significantly
resistant in comparison to the ones currently on the market (Terenzi 2013: 110–122). From the
chemical perspective, it has been observed that the organic material, naturally present in the waste
used, is alone enough to foam the glass without the help of additional agents which, otherwise,
would have to be added to the mixture” (Tartaglia and Terenzi 2016).
231
and treatment of waste and production of concrete products). In particular, the team
included: Unibloc s.r.l. (operating in the sector of concrete vibro-compressed components, responsible for the research was arch. Riccardo Cecconi) as group leader
and supported by Assobeton; S.A.M. Engineering S.p.A. (construction company
also operating in the production of prefabricated concrete panels, responsible for
the research was engineer Tiberio Pochini); La RevetVetri s.r.l. (operating in the
separate collection of urban waste, responsible for the research was engineer Massimo Ravagnani); DiDA—Dipartimento di Architettura of Università degli Studi di
Firenze (scientific partner, responsible for the research was Alessandro Ubertazzi
with Benedetta Terenzi); ABC department—Architecture, Built environment and
Construction Engineering of Politecnico di Milano (scientific partner, responsible
for the research was Andrea Tartaglia).
The idea was to transform a waste normally disposed of in landfills into a “new”
raw material. Moreover, the reuse for construction components had to be conceived
by verifying its environmental compatibility, technical feasibility and economic sustainability.
The first step was therefore to identify how and in what to “transform” the waste
from glass recycling. Thanks to the support from Enrico Bernardo and the alternative
production processes designed by him, the use of the waste for the production of foam
glass was identified as the best solution
4 (Table 1). This is a product already widely
used in the construction sector in Northern Europe especially as an aggregate in
concrete mixtures. The significant advantages related to the processes proposed by
the “Ethical concrete” study are primarily:
– The use of waste and not of new resources and components saving the use of a
huge amount of non-renewable resources;
– A production process that requires lower temperatures compared to the typical
process that starts from new raw materials, this means a reduction in the quantity
of energy involved in production;
– The normal presence of organic elements in the waste that allows the activation
of the foaming process without the use of additives, with a further advantage over
the use of resources.
4 To obtain this result “several alternatives have been tested for the waste glass processing in order
to achieve an adequate glass sand that can undergo the necessary heat treatment to obtain foam
glass. As a consequence of this effort, a virtuous circle has started with the ambitious goal of giving
dignity to a new material from a waste product which currently is simply disposed of in dumps. A
series of samples with slightly different physical–chemical characteristics have been produced with
tests run by the researchers, according to the procedures used in the thermal process to obtain the
material set by prof. Bernardo. By comparing the different properties of the foam glass samples
obtained, the partners of this project have identified as the most interesting material, according to
the set goals, the one with the best ratio between compressive strength and density, therefore, with the
best specific resistance. This is because the aggregates are not particularly light but significantly
resistant in comparison to the ones currently on the market (Terenzi 2013: 110–122). From the
chemical perspective, it has been observed that the organic material, naturally present in the waste
used, is alone enough to foam the glass without the help of additional agents which, otherwise,
would have to be added to the mixture” (Tartaglia and Terenzi 2016).