Alejandro Josa

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ECO-SERVE Workshop Blending cements Tuesday 25
May 2004 Facility Port, Leuvensesteenweg 369,
Sint-Stevens-Woluwe
Environmental Thinking in the Construction
Industry

• Alejandro Josa
• Ciment Català - Catalan Cement Association

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Context of the presentation The assessment and
minimisation of the environmental impact of
construction activities. Tool currently
available Life Cycle Assessment of processes and
products (LCA).

• Objectives of the presentation
• To briefly explain
• why environmental assessment is necessary
• what an LCA is
• and what the main applications of LCA methodology
  are.
• Also as an introduction to the EcoConcrete
  software

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• Contents
• 1. Introduction
• Why is environmental assessment necessary?
• 2. LCA of processes and products
• Brief description of the LCA methodology
• 3. Applications of LCA
• Some examples of applications of LCA results
• 4. Final remarks

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• 1. Introduction
• Why is environmental assessment necessary?

• There has been a huge increase of human activity
  (and its effect on the environment) during the
  last few decades
• Examples
• Evolution of some parameters from 1950 to 2000
• World population has more than doubled (now
  slowing down)
• Forest exploitation has more than doubled
• Water consumption has more than tripled
• Oil consumption has more than sextupled
• Economic activity has more than quintupled

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increase of contamination in
Environmental interventions Inventory
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• Is all this relevant?
• (Perhaps there are no negative effects)
• Are these trends acceptable?
• Can the Earth bear this environmental load?

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Some signs say that these trends are not
sustainable. Examples
Reduction of The total amount of potable water
The agricultural production per capita The total
fishing banks Etc.
Environmental effects. Increase of Greenhouse
effect (global warming/climate change) Ozone
layer depletion Acidification Eutrophication Toxic
ity of air, water, soil Generation of wastes Etc.
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Environmental impacts
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• A significant part of these impacts come from the
  construction sector (construction, use and
  maintenance of infrastructures).
• The impact of use and maintenance can be
  significantly more important than the impact of
  construction.
• Examples roads or buildings.

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• Objective to change the observed trends
• Essential initial step to identify and minimise
  the main impacts produced on the environment
• Next steps to minimise the impact produced by
  any activity on the environment
• To accomplish the above a method for assessing
  the environmental impact of any process or
  product is needed
• Method developed LCA (selected among several
  options)

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• 2. LCA of processes and products
• Brief description of the LCA methodology

LCA (Life Cycle Assessment) is a method,
developed mainly after the late 1980s, that
quantitatively assesses the impact of processes
or products on the environment. It is currently
accepted as a reference method by Governments,
NGOs, industry, etc.
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Examples of processes or products
Quantitative assessment of all measurable effects
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Examples of parameters assessed
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• Key aspect in an LCA Life Cycle

The LCA of a product must take into account the
environmental impact produced throughout its
whole life (from cradle to grave).
Example of Life Cycle for a concrete product
Relevant impacts can be produced in any of the
stages of the Life Cycle
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To be defined - functional unit - cradle-grave,
cradle-gate - system boundaries
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Examples A badly isolated building may have a
lower environmental impact up until construction
is completed (fewer materials required) but will
have a much higher impact during use because of
thermal conditioning. A material can have an
important impact in production (for instance high
energy consumption) but very low afterwards (low
maintenance and recyclable) or vice versa.
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What if function changes?
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To effectively minimise the whole impact on the
environment all stages must be taken into account
in the conception (planning) one, especially the
deconstruction (reintegration)
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Stages of a Life Cycle

• For each stage of the Life Cycle

Final result addition of the environmental
impact of the different stages of the Life Cycle
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Some critical points System boundaries What is
included and excluded in the Life Cycle. It is
impossible to take everything into account or to
go back infinitely (for instance the impact of
the production of the kiln or the
overheads). Allocation of impacts How impacts
are distributed in processes with multiple
exits. For instance the impact associated with
fly ashes or slag (product or waste?) Data
quality Data quality can vary greatly (in some
cases accurate figures are difficult to be
obtained). These points, among others, can
significantly change the results.
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• Some analysis are not cradle to grave
• (Needed as part of a complete LCA or used for
  analysing specific stages of a Life Cycle)
• Cradle to gate for instance the analysis of
  cement production including pre-stages.
• Gate to gate for instance the analysis of
  recycling.
• Gate to grave for instance the analysis of
  demolition and landfill.

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• 3 main results from an LCA

1. Inventory (LCI) detailed list of all
environmental interventions (materials used,
gases emitted, wastes produced,
etc.). 2. Assessment (LCIA) reduction of the
large number of LCI interventions to a reduced
number of impacts (6-12) based on scientific or
empirical correlations. There are different
methodologies for this aggregation. The number
and type of impacts selected depend on the
methodology. The results can be normalised
(relative to reference figures). 3. Single
Score reduction of the result to a unique final
score based on non-scientific preferences
(social, political). There are also different
methodologies for this aggregation.
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Example of (long) inventory
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Example of LCI for 1 kg of cement
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Examples of impact categories of different
methodologies
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• From the inventory to the impact categories and
  the single score

• For each category (greenhouse effect,
  acidification, etc.) the following steps are
  taken
• Classification of the LCI interventions affecting
  the corresponding category.
• For instance, for greenhouse effect, CO2 or CH4
  are included, and NH3 excluded, and for
  acidification NOx, NH3, SO2, HCl or HF are
  included and CO2 or CH3 are excluded.

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• Characterisation of each LCI intervention in each
  impact category.
• Factor transforming the intervention to the unit
  of the corresponding impact category (based on
  experimentation or models).
• For instance, for greenhouse effect the unit is
  kg of CO2 and in the case of CH4 its effect is 11
  times greater than that of CO2 consequently, the
  amount of CH4 is multiplied by this factor and
  added up to the amount of CO2 and for
  acidification the unit is kg of SO2 and the
  factor for NH3 is 1.88.

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• Normalisation of results.
• Sometimes the results for each impact category
  are divided by a reference - for instance the
  total amount of the corresponding impact in
  Europe or in the world - and the result becomes
  adimensional.
• Single score.
• In this case, the results of the interventions or
  of the impact categories are added up using
  coefficients based on social/political
  preferences and output a single score.

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• Parts of an LCA study

• Normally an LCA study is composed of the
  following four parts
• 1.Definition of goal and scoping (functional
  unit, system boundaries, origin of data,
  objectives, etc.).
• 2.Inventory analysis.
• 3.Impact assessment (classification,
  characterisation, normalisation, valuation -
  single score).
• 4.Interpretation, improvement assessment and
  conclusions.

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3. Applications of LCA Some examples of
applications of LCA results
Basic objective Minimisation of the impact
produced by processes and products on the
environment (the assessment is needed for it)
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• Examples of applications of LCA results
• As a tool of environmental analysis and
  management for
• analysing and improving processes (for instance a
  production system) or products (for instance a
  beam)
• comparing alternatives with the same
  functionality (for instance two buildings through
  their whole life)
• defining the environmental performance of
  processes or products (for instance EPDs)
• giving Quality Marks (Ecolabels)
• or establishing environmental priorities
  (through the structure of the final score).

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• There are studies conducted in various European
  countries with different objectives (not all
  public).
• In general it is difficult to extend the results
  to other cases or situations because of
• the specific situations analysed which, in
  general, cannot be extrapolated
• the different assumptions adopted (not always
  explained in detail)
• and the current incomplete standardisation.
• Examples in the field of construction beams,
  pavements, pillars, railway sleepers, sewage
  pipes or bridges, among others.

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Results are usually given as a set of values
corresponding to each environmental intervention
(LCI) or impact category (LCA) (except when a
single score is obtained). Comparisons with sets
of results are more difficult and can have no
definitive results if each alternative scores
better than the other for some parameters but not
for all of them. With a single score the
comparison is easy but its meaning depends on the
assumptions made.
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• 4. Final remarks

1/3 The need to assess and minimise the
environmental impact of any activity is evident,
particularly by the construction activity.
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• 4. Final remarks

2/3 LCA is a method, that quantitatively assesses
the impact of processes or products on the
environment and is, in general, accepted as a
reference method by Governments, NGOs, industry,
etc. but it is not completely standardised (yet)
and different methodologies and assumptions,
leading to different results or type of results
(sometimes very different), can be used, which
means that its results are not always completely
definitive.
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• 4. Final remarks

3/3 LCA enables environmental improvement of
processes and products through the comparison of
alternatives fulfilling the same function.
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• Thank you for your kind attention

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ECO-SERVE Workshop Blending cements Tuesday 25
May 2004 Facility Port, Leuvensesteenweg 369,
Sint-Stevens-Woluwe
Environmental Thinking in the Construction
Industry

• Alejandro Josa
• Ciment Català - Catalan Cement Association