Download Establishment of a method for the selective demolition of buildings

Establishment of a method for the selective demolition of buildings with PCB-containing
materials (for use in a wide range of sites)
The main aspects to be considered in relation to the presence of PCBs in the production of
C&D waste, waste streams, handling and disposal methods, and environmental and economic
impacts are:
- Amount of C&D waste, and thereby the quantity of PCBs
- Disposal
- Legislation and control
The amount of C&D waste generated in a society is closely related to the activities of the
building and construction industry. It is widely recognised that the conditions of the building
and construction industry and the level of activities vary throughout the decades and among
the Member States. The level of activities is closely related to, among other things, the state of
industrial development of the country as well as the type of industry and political initiatives.
Legislation concerning building and construction virtually controls the level of activity within
the industry.
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Identification of materials in buildings containing PCBs
Evaluation of building structures and materials containing PCBs
Evaluation of traditions and types of different building structures (in general) within
Europe. This includes different types of structures, including steel, concrete, brick and
wooden structures.
Generally, European dwellings are supposed to have an average lifetime of 50 to 100 years,
and industrial buildings and structures have a considerably shorter lifetime. Outside Europe
the lifetimes are often considerably shorter. Repair work on buildings and structures takes
place on a running basis. Larger repair and renewal works are typically carried out around
mid-age, being approximately 25 years.
The issue of construction types and traditions is raised in the report on C&DW from DG
ENVDG ENV. The types of considerations are related to what affects the nature and volume
of C&DW.
Traditions and types of different building structures (in general) within Europe can in short be
described as follows:
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individual family dwellings are predominantly built of blocks, brick and wood, with wood
used much more widely in Scandinavia than elsewhere in the EU;
The 1950s and 1960s apartment buildings which accommodated the flood of workers to
post-war urban industrial centres in most Member States were generally built of
reinforced concrete, with copper piping replacing lead;
By the 1980s plastics (especially PVC double glazing units) were becoming widespread in
pipes and window frames in all sorts of residential buildings;
Many industrial and commercial buildings erected since the 1980s have benefited from
faster construction techniques based on steel frames, reflecting a lower demand for steel
from heavy industry;
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Steel-framed structures lack the ‘natural’ fire resistance provided by concrete and brick,
requiring much more fire proofing of beams and columns (often involving hydrocarbonbased materials) and fire fighting systems (often involving chemicals which may
themselves be hazardous such as PCBs);
Irrespective of the primary materials from which they were constructed, older buildings
are more likely to contain hazardous material such as asbestos, CFCs and PCBs, because
controls on these materials have been tightened over time;
Similarly, as restrictions have been imposed on the use of hazardous materials in
commerce and industry, so the potential for contamination of the fabric of building
structures from the products containing hazardous substances used, and from the wider
environment, has decreased;
Bonding also makes full separation of waste streams more difficult;
The changing balance between road construction and maintenance (as well as associated
infrastructure such as bridges and tunnels) affects the materials arising.
Evaluation of static stability of buildings (identified structures of relevance)
- Frames with fire retardant, - ongoing task
Evaluation of known methods of selective demolition
The construction process of buildings and structures is normally carefully considered and
planned. The other processes in the life cycle, especially demolition, are often neglected
owing to a lack of understanding of the importance of integrated resource/environmental
management. The achievement of e.g. cleaner technology within the building and
construction industry requires a detailed knowledge and understanding of all processes and
careful consideration of all sorts of input and output of the single processes with respect to the
environment, and brings into focus the related costs.
Planning demolition projects
A necessary condition for “clean” building waste is careful previous sorting of the waste.
Waste from new construction and rehabilitation work is sorted either at production site or at a
special treatment site. This separation of material categories is fairly simple.
The sorting of the building waste from demolition is, however, a more complicated process.
Demolition has for many years been regarded as a low technological process. Rapid
demolition and disposal of structures were the main aim of the contractor. Special measures to
separate the different types of materials were not possible owing to the time factor, nor were
(are) they desired.
Optimal handling of the building waste depends on the materials being sorted in-situ and in
co-ordination with the demolition process. It is therefore, necessary to alter the former and
often traditional methods of demolition and introduce selective demolition as the method to be
used.
This requires that before and during the demolition process a planned and concise sorting of
the different material categories is carried out, thereby preventing any mix of the waste with
materials containing PCBs. Having materials mixed with PCBs leads to pollution of the
building waste material and a requirement for special treatment of unnecessarily large
quantities of waste materials. The goal must be to minimise the waste quantities requiring
special treatment and disposal, leading to optimum recycling and environmentally friendly
disposal of building waste materials.
It is therefore necessary to plan and conduct demolition work as selective demolition. This is
in principal carried out as the reverse of the construction process and follows the following
procedures: PLEASE DEVELOP THIS FOR PCBs
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Removal of remains and non-fixtures.
Stripping, comprising internal clearing, removal of doors, windows, roof
components, installations, water, heating and electric installations and so forth.
This leaves only the bearing and main structures of the building in place.
Demolition of the bearing and main structures.
Since selective demolition needs time for these procedures, it is recommended that demolition
projects should in principal be planned and controlled in detail, likewise all other building and
construction projects, to ensure selective demolition and correct handling and disposal of the
demolition waste.
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Evaluation of interrelated activities and risks, technically as well as economically in
selective demolition.
Identification of method(s) for the selective demolition of buildings with PCB- containing
materials. In this respect Selective Demolition can be defined as a method to be used
before and during a demolition process. This involves the sorting of materials into
different fractions with the aim of avoiding a "mix" of materials (which would pollute
otherwise clean and possibly recyclable materials with PCB-containing materials).
Separation of hazardous materials
Council Directive 91/689/EEC establishes a list of criteria (in its Annex III) to be used when
the hazardous of wastes is being determined. Subsequently the Commission has drawn up a
list of hazardous wastes published as Council Decision 94/904/EEC (the hazardous waste list)
as amended by Commission Decision 2000/532/EC.
Very few materials, which may be classified as C&DW, are invariably hazardous as defined
in Directive 91/689/EEC or Decision 94/904/EEC. One of the most obvious examples of this
small group, and certainly the one most frequently cited, is asbestos-based insulation.
However, some other materials may be hazardous because they display one or more of the
characteristics used in the Directive’s Annex III to define 'hazardous' (such as toxicity or
flammability). These characteristics may only be revealed under specific circumstances, and it
may be possible to avoid those circumstances. (Ref.: C&DW report from DG ENV)
Furthermore, some other waste materials that are found in relatively small amounts in
C&DW (such as paint and plastics), although not necessarily hazardous, are not inert either.
For the sake of the much larger inert fraction, such materials should be kept separate from the
inert fraction if at all possible. If they are not, it may not be possible to treat the main bulk of
the materials as inert.
The general conclusion is that selective demolition (separating materials at source) is a very
desirable activity, which should be encouraged, and possibly even required. Although local
planners and regulators should take into account the availability of recycling and disposal
facilities when encouraging or requiring selective demolition, they should also recognise that
the two issues are interrelated. While they should not overwhelm local facilities by requiring
them to deal with more materials than they can sensibly handle, they can by their decisions
stimulate to expand the capacity by introducing a clear and consistent policy on selective
demolition.
Economies of scale mean that organising and controlling hazardous materials should be easier
on large sites than on small ones. On demolition sites, matters can be greatly helped if a
proper pre-demolition survey is organised.
The C&DW-report from DG ENV(1999) only identifies some of the potentially hazardous
materials containing PCBs that most likely may be encountered as a result of demolition
activities, including the refurbishment of existing buildings. This includes power transfer
equipment and lighting (electronics). The report identifies the potentially hazardous, the
properties that make them potentially hazardous, and some of the options most likely to be
considered for their treatment and/or disposal, in this case being removal for specialist
disposal, see Table 4.
Waste Streams
1 Some C&DW streams are hazardous
because the materials originally used
contained a high proportion of materials,
which were themselves hazardous.
2 Some materials become hazardous as a
direct result of the environment in which
they have existed for many years.
Examples
Examples include asbestos, lead, tars, paint
and preservative residues, adhesives, bonding
agents and sealants and certain plastics.
An example would be a factory where surface
reactions between the originally nonhazardous building materials and chemicals
carried in air (or water) pollution associated
with the processes in or near the factory
resulted in parts of the building’s fabric
becoming hazardous, and requiring special
handling or treatment.
CHECK THE MIGRATION OF PCBs
FROM SEALANTS INTO CONCRETE
3 Some C&DW streams become hazardous The classic example concerns lead-based
if hazardous materials are left in them
paint tins thrown onto a pile of bricks and
and/or subsequently get mixed with
concrete, making the whole pile hazardous
them.
waste.
Table 4. Types of Hazardousness in C&D-Waste. Source: C&DW Management Practices,
European Commission, DG ENV, February 1999.ACCORDING TO THIS TABLE, WOULD
THAT MEAN THAT THIS REQUIRES 3 DIFFERENT IDETIFICATION APPROACHES
FOR PCBs?
When the electrical equipment is finally taken out of service in connection with a demolition
project measures must be taken to handle the equipment in a safe manner and place it in
secure storage prior to disposal. Care must be taken to avoid losses and especially to avoid
contamination of the storage building and other materials stored there, including wastes, to
avoid increasing the quantity of materials needing to be classified as PCBs and thus requiring
special disposal. Any pre-treatment or storage activity related to transportation or final
disposal must similarly reflect the requirement to avoid leakage and spillage and to ensure
containment of all the waste up to its moment of disposal (ref.: Basel Convention, Technical
guidelines, 1997).
The effective containment, collection and storage of any minor leakage and spillage, which
might occur, are essential. Extreme care at the time of removing the equipment is important.
Those engaged in removing that equipment should be specially trained in these process and
clean-up procedures.
On demolition sites there are always likely to be some materials (such as asbestos and
sodium/mercury vapour lamps, electrical equipment containing PCBs) which are hazardous in
their own. Residues of hazardous substances manufactured, used or stored at the site may
remain (e.g. industrial sites). Where possible these should be removed from the site prior to
demolition activities commencing. If they have become impregnated into the fabric of the
building it may be possible to neutralise or treat them in situ prior to demolition.
Some specific hazardous and potentially hazardous items that may be encountered on
demolition sites are listed below:
(i) asbestos-based materials;
(ii) treated timber (might include PCBs);
(iii) mineral fibres (insulation);
(iv) electrical equipment containing PCBs and other toxic components;
(v) CFC-based refrigerants;
(vi) CFC-based fire fighting systems;
(vii) radionuclides;
(viii) biohazards (PCBs and others);
Some materials may be inert or relatively non-hazardous in situ, but could become hazardous
depending on the disposal method. For example some treated (TREATED WOOD IS
HAZARDOUS ALSO IN SITU, NOT ONLY UPON DISPOSAL) or coated timber, if
incinerated, can give rise to toxic fumes similar to PCBs.