Life Cycle Assessment of Civil Engineering Works: And Application of European Standards on the Mälar Project

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IN

DEGREE PROJECT TECHNOLOGY, FIRST CYCLE, 15 CREDITS

STOCKHOLM SWEDEN 2019,

Life Cycle Assessment of Civil Engineering Works

And Application of European Standards on the Mälar Project

MALIN ERIKSSON

KTH ROYAL INSTITUTE OF TECHNOLOGY

SCHOOL OF INDUSTRIAL ENGINEERING AND MANAGEMENT

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Abstract

In this thesis, a framework is constructed for a life cycle assessment within a civil engineering project. There are various methods available on how to conduct life cycle assessments and this thesis explores one method related to civil engineering works. The assessment follows the structure based in related standards such as EN 15804 which describes how to declare construction products. A working copy of a possible upcoming European level standard for sustainability assessment of civil engineering works is also used in the process. The object of assessment are the materials, concrete and steel, in the retaining walls that are constructed along the channel near Södertälje Harbour. This is a part of a larger project, called the Mälar Project.

The life cycle of these type of constructions often stretches over long periods of time which leaves a lot of uncertainties while estimating the impacts during the later life stages. The research problem is much about how to handle the different modules of the life cycle regarding civil engineering works.

Example data were collected and presented for each module of the life stage.

The results of the example data showed that most of the impact came from the product stage. The conclusions are that the collection of data should be an integrated part in the operating procedures for the company for a more efficient process, Environmental Product Declarations are a good source of data and standards on European level gives good guidelines on how to conduct a life cycle assessment for civil engineering projects.

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Sammanfattning

I detta examensarbete konstrueras ett ramverk för hur en livscykelanalys kan ut- föras inom väg- och vattenbyggnad. Det finns många olika riktlinjer för hur en livscykelanalys kan utföras och i detta examensarbete utforskas en metod för projekt inom väg- och vattenbyggnad. Arbetet följer strukturen ur EN 15804 som beskriver hur man bedömer byggprodukter. Ett arbetsexemplar av en ny, möjlig standard på Europanivå för miljöbedömning av projekt inom väg- och vatten an- vänds också i processen. Det som bedöms via livscykelanalys i denna studie är de ingående materialen, stål och betong, i hållväggarna som byggs längs med kanalen vid Södertälje Hamn. Detta är en del av ett större projekt, kallat Mälarprojektet.

Livscyklerna för denna typ av projekt är oftast väldigt långa vilket skapar en osäkerhet i data då påverkan för senare delar av livscykeln behöver uppskattas.

Problematiken som presenteras handlar mycket om hur modulerna för livscykeln ska behandlas för denna typ av projekt.

Exempeldata samlades in för de olika modulerna och presenterades i tabeller som täcker alla relevanta delar av livscykeln. Resultatet av exempeldatan visade att den mesta påverkan kom från produktstadiet. De slutsatser som dras är att insamlingen av data bör vara en integrerad del av företagets arbetsmetod för en effektiv process, miljödeklarationer är en bra källa till data och standards på Europanivå ger bra guidelinjer för hur en livscykelanalys kan utföras för liknande projekt.

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Acronyms

SDGs - Sustainable Development Goals

CEN - European Committee for Standardisation ISO - International Organisation for Standardisation LCA - Life Cycle Assessment

LCI - Life Cycle Inventory

LCIA - Life Cycle Impact Assessment GWP - Global warming potential

EPD - Environmental Product Declaration ILCD - Life Cycle Data System

PCR - Product Category Rules

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1 Introduction

The 17 Sustainable Development Goals (SDGs) of the 2030 Agenda was adopted by world leaders and officially came into force on January of 2016 [1].

In November of 2016, COP21 took place in Paris and countries also adopted the Paris Agreement. In this agreement, all countries agreed to work to limit global temperature rise to well below 2 degrees centigrade. In April of 2018, the agreement was established by 175 parties and 10 developing countries had submitted international adaption plans for responding to climate change.

Climate change is a global challenge that does not respect national borders.

Greenhouse gas emissions are historically at its highest level which causes weather patterns to change and sea levels rise.

Climate change is also one of the SDGs, which strives to take urgent action to combat climate change and its impacts [2].

Life cycle assessment is a tool within environmental management that helps sustainability specialists, designers and engineers to critically evaluate products and technical systems and considered alternatives.

In order to keep the results comparable and unbiased, international standards were developed within the International Organisation for Standardisation (ISO).

European Committee for Standardisation (CEN) have worked to further develop standards for specific types of assessments, such as evaluation of construction materials or buildings. A brand-new standard from CEN is now in the work for sustainability assessment methodology of construction works, covering projects within civil engineering.

1.1 The Mälar Project

The civil engineering project covered in this thesis is the refurbishment of the lock in Södertälje Harbour, which has now reached the end of its life cycle. The project is called the Mälar project. It is a commission from the Government of Sweden, overseen by the Swedish Maritime Administration, who is the authority responsible for Swedish shipping. The project is partly financed by the Trans- European Transport Network (TEN-T). The purpose of the project is to increase accessibility and improve safety along the Södertälje Canal.

The canal will be broadened below the water surface. Along a 3 km part of the canal, 25 m deep retaining walls will be constructed on both sides to straighten the bends near the bottom of the canal. Where it is necessary, the fairways of Lake Mälaren will be deepened, or dredged.

One important driving force for the project is the increased capacity for transport. By improving the infrastructure, railways and road networks with heavy traffic can be unloaded as the harbours will be able to receive larger ships. Today, the maximum for tanker ships is 5 800 ton fuel, which is equivalent to 200 tankers within the road network. With the expanded floodgate, a ship could carry up to 9100 ton fuel, equivalent to 300 tankers.

The new lock will be finished for deployment in the year end 2019/2020 [3].

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1.1.1 Züblin Scandinavia AB

Züblin Scandinavia AB is the constructor of the Mälar Project. Business fields include foundation work, building construction and infrastructure.

Züblin Scandinavia AB is an affiliated company to the German Ed. Züblin AG which is a part of the STRABAG concern with more than 73 000 co-workers.

Züblin Scandinavia AB has 130 employees in Sweden with offices in Stockholm, Sundsvall and Gothenburg [4].

1.2 Research Problem

There are various standards and guidelines on how to conduct a life cycle assessment. This thesis examines which standards that are beneficial for civil engineering works and one method for conducting a life cycle assessment within the Mälar Project is presented.

It may be hard to identify all the sources affecting the results of a life cycle assessment. This thesis also examines the benefits of using a new standard on European level for sustainability assessment in the process of identifying all the important factors that impacts the environmental sustainability performance of civil engineering works. This standard is not yet published and only available as a suggestion.

1.3 Aim and Scope

The goal for Züblin Scandinavia AB is to start working with life cycle assessments and to identify potentials to improve their sustainability performance in the future.

The aim of this thesis is to model one method for life cycle assessment of the construction materials, concrete and steel, used in the Mälar Project. This framework can be extended later by Züblin Scandinavia AB for at full life cycle assessment.

The results may also be used for ratings within the sustainability assessment tool, CEEQUAL^R. Points are collected if a life cycle assessment has been done for one or for all materials used within the project.

The different stages and phases of a life cycle assessment will be described more thoroughly in the literature review.

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2 Literature Review

This literature review presents methodology and characteristics of Life Cycle As- sessment (LCA), and the use of LCA within civil engineering.

2.1 Main Characteristics of LCA

There are some characteristics that distinguish LCA as a tool for sustainability assessment, described further below.

2.1.1 Life Cycle Perspective

LCA takes a life cycle perspective when evaluating environmental impacts of a product or a system. This means to consider multiple stages of the life cycle.

For construction works, as seen in Figure 1, it could mean to not only consider the use-stage of the construction, but also the industrial and agricultural processes prior to the delivery of the building materials, as well as demolition of the construction and reuse/recycling of the materials.

Figure 1: Life cycle of construction works.

The life cycle perspective of LCA allows for comparison of various environmental impacts of systems made up of different processes and multiple use of resources.

It can also identify and prevent burden shifting between different stages in the life cycle. Otherwise, substituting one stage in a process could unintentionally create possibly larger environmental impacts in other processes in the life cycle. To consider the whole life cycle of a product or system refers to a "cradle to grave" LCA.

It may also be cases where it is motivated to only consider parts of the life cycle, called "cradle to gate".

The life cycle perspective may also be a limitation as it requires simplifications while modelling the system and building the framework for the LCA. These simplifications prevent the LCA of calculating actual environmental impacts and are also aggregated over time and space. Therefore, it is more accurate to say that LCA calculates impact potentials.

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Another limitation for LCA is that it cannot tell whether the results are "good enough". LCA can allow for comparison between different products but it does not conclude that the product is environmentally sustainable [5].

2.1.2 Broad Range of Environmental Issues

LCA covers a broad range of environmental issues which, for building materials includes the impact categories; global warming, ozone depletion, acidification for soil and water, eutrophication, photochemical ozone creation and depletion of abiotic resources [6].

Burden shifting is prevented by considering multiple environmental issues since efforts for lowering one type of environmental impact may increase other types.

For each category there are several substance emissions or extraction related events that contribute to the environmental impacts.

2.1.3 Quantitative

Another important characteristic for LCA is that it is quantitative. All sorts of emissions and use of resources are mapped and measured. The quantitative nature of LCA makes it possible to identify hot spots in the life cycle or to point out which processes that contribute the most to the overall impact and therefore should receive attention. The data may also be used for comparison of different products or systems with the same function. The method of "best estimate" is generally applied, where the values is chosen with consistency and with the closest accuracy. If it is possible to obtain actual values, they should be used. Otherwise, data could be found in various databases for LCA. It is important to describe the quality of the data being used in the study to properly interpret the outcome of the study and to understand the reliability. The complexity of these input data is then reduced into a manageable number of environmental issues, previously called impact categories. Each environmental impact is measured and declared in functional units [5]. The functional unit quantifies the identified functions of the system being studied. The purpose of this is to make a reference to the relations of the flows going in and out of the system (e.g. in- and outputs). This makes it possible to compare different systems on a common basis [7].

2.1.4 Based in science

The relationships between emissions of these substances and environmental impact are based on science and proven causalities, through chemical reaction schemes for example in the formation of ground level ozone from nitrogen oxides, or empirically observed relationships. The quantification of potential impacts is generally based on measurements, for example from water gauges or particle counters at industrial sites or mass balances over the processes. Mathematical cause/effect models are used to calculate potential impacts on the environment from the emissions and use of resources [5].

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2.2 Phases of LCA

This part of the literature study describes the general principles and framework for LCA, described in the ISO 14040 standard. A scheme of the basic framework can be seen in Figure 2. Different levels of standardisation will be described in later sections.

Figure 2: Framework for life cycle assessment [8].

2.2.1 Goal and Scope Definition

The goal definition of an LCA describes the intended application and the reasons for carrying out the study. The intended audience and to whom the results are intended to be communicated should also be stated. Purposes of conducting an LCA may be to identify possibilities to improve sustainability performance, to give information to decision support, marketing purposes, or strategic planning.

The system boundary and the level of detail will depend of the intended application and use of the study. The scope definition describes the system being studied and its functions. If the use of the study is intended for comparison, one should also describe the functional unit, system boundary, allocation procedures (i.e. how to distribute the input or output flows between the system being studied and other systems), impact categories selected and methodology of impact assessment.

The goal and scope definition also require a description of data quality, assumptions and limitations.

LCA is an iterative technique, as seen in Figure 2, and the scope may require some modification while collecting data to meet the original goal of the study.

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2.2.2 Inventory Analysis

The phase of collecting data to meet the goals of the defined study is called Life Cy- cle Inventory (LCI). It is the next step after defining the goal and scope. The phase consists of compiling and quantification of input and outputs for the defined system throughout its life cycle. It catalogues the flows that cross the system boundaries and sets the foundation for the life cycle impact assessment. The collection of data can be classified under inputs, waste, emissions and other environmental aspects [7].

There are cases when an LCA consist of only inventory analysis and an interpretation and this is referred to as an LCI study [5].

2.2.3 Impact Assessment

In the phase of Life Cycle Impact Assessment (LCIA), the LCI results are used to evaluate significance and potential environmental impacts. The inventory data is associated with the specific impact categories. This phase provides information to the interpretation phase.

Mandatory elements for the LCIA phase include selection of impact categories, category indicators and characterisation models, as well as assignment and calculation of the results.

The LCIA only addresses the environmental issues that are specified in the goal and scope and is therefore not a complete assessment of all the environmental issues related to the system being studied. It may also be other uncertainties that limits this phase such as that the system boundary does not include all in- and outputs due to cut offs and data gaps, inadequate LCI data quality and limitation in the collection of representative data for each impact category.

2.2.4 Interpretation

In case of an LCI study, this phase consists of only the findings of the inventory analysis. Otherwise the results are combined with the impact assessment. The results of this phase should be consistent with the goal and scope and explain conclusions, limitations and recommendations [7].

2.3 Global warming potential

Global warming potential (GWP) is an indicator on how much a product or system contribute to climate change, measured in kg CO₂ eq. Different kinds of emissions of greenhouse gases may contribute differently to climate change. Methane, for example is a much stronger greenhouse gas than CO₂. Therefore, there are different equations developed on how to calculate which factor to multiply with the amount of methane to make the impact equivalent to the same amount of emitted CO₂.

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2.4 Challenges of LCA within the Built Environment

The built environment is an umbrella term for buildings, infrastructure and the human activity between, like for example production of materials, waste treatment, electricity consumption, construction and renovation.

LCA for a single product is often of a high accuracy where a normal temporary scope snapshot is typically around a calendar year. The life cycle of construction works within the build environment stretches over long periods of time, often a century. This generates uncertainties regarding the end of life stage and therefore the results are much depending on the defined scenarios for the use and after-use stages.

The materials used in the built environment may carry embodied energy and natural resources. The recycling potential express how much of the elements that could, through reuse or recycling, benefit later product systems.

State of the art on how to set the impact assessment indicators for recycling potentials can be found on European level. The European Committee for Stan- dardisation (CEN) has developed a framework for the environmental declarations of building materials, where a predefined set of indicators is established [5]. A more detailed description of this standard will be given under the section of standardisation, later in this literature review.

2.5 Standardisation of LCA

LCA is a relatively young discipline with around 50 years of history. The methodology and applications have matured over the years in the sense of scientific con- sensus, and standards have emerged.

The first standard that was developed by International Organisation for Stan- dardisation (ISO) was ISO 14040, which appeared in 1997 and describes the LCA framework. The fundamental structure has been stable since then. Over the next seven years, four new standards were released, addressing the principles and framework (ISO 14040), the goal and scope definition (ISO 14041), the life cycle impact assessment (ISO 14042) and the life cycle interpretation (ISO 14043). The standards were revised and adopted by CEN, in 2006. The latter three were compiled in the ISO 14044 standard detailing the requirements and guidelines, concerning the LCA methodology [5].

In accordance with the intended application of the LCA, organisations have the flexibility to implement LCA after their own requirements. The ISO 14040 describes the fundamental principles and framework in general for LCA. There is no one single method for conducting LCA [7].

The standards are not very detailed on specific methodological choices. The European Commission developed an International Life Cycle Data System (ILCD) with a database of life cycle inventory data and a series of methodological guidelines in the mid-2000s [8].

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2.5.1 Environmental Product Declarations

EN 15804 is a European standard, developed by CEN. The process of standardisation has taken place in accordance with EN ISO 14025, which describes how to make environmental declarations of a products life cycle. EN 15804 describes how to make an Environmental Product Declaration (EPD) for construction materials and provides the core rules for the product category of construction products (PCR). The purpose of this standard is to harmonise the way that EPDs are verified and presented, this allows for comparison of different products with the same function. EN 15804 is a part of a suite of standards that are intended for assessment of sustainability of construction works and covers the declaration of construction products. Assessment of social and economic performances is not covered by this standard. Topics covered in the core PCR are;

• How to declare, collect and report information.

• Description of which stages to consider in the products life cycle and the processes to include in the life cycle stages.

• Rules for developing scenarios for future stages.

• Rules for calculating the Life Cycle Inventory and the Impact Assessment, including data quality.

• Rules for reporting predetermined, environmental and health information that is not covered by the LCA.

• Defines the conditions on which construction products can be compared.

The different stages of the life cycle of construction works is divided into modules. There are various options within this standard to make an EPD for the full life cycle (cradle to grave) or for limited stages (cradle to gate). The modules A1 - A3 is always mandatory when reporting an EPD and covers the stages from extracting the raw materials to manufacturing the product. Organisations can choose to use actual, measured values for the processes, or use average values from various databases for similar products. The process of collecting data shall follow the guidance provided in ISO 14044 [6].

When choosing data for construction products, EPDs are generally considered to contain the most product specific and correct data. There can be a lack of consistency and transparency in this since variation occurs over different national EDP programmes and the product category rules they use. Also, to protect property rights of the manufacturer, only LCIA and not LCI data is presented.

Generic data on building materials are also limited since LCA databases mainly covers industrial products, and not biomaterials or innovative materials [5].

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2.6 Sustainability Assessment

2.6.1 European Standardisation

A new standard is under development by CEN. It is a work in progress and the standard is not yet published of verified externally. The purpose of this work is to provide rules for the assessment of the sustainability of civil engineering works. The standard supports quantification of the sustainability performance while taking the functionality and technical characteristics into account. The primary purpose of this standard is to support decision making for a project and providing a standardised method to enable comparison of scheme options.

This European standard will possibly provide requirements for;

• How to describe the object of assessment.

• How to set the system boundary, applied at civil engineering work level.

• Procedures used for the analysis.

• Definition of the declared indicators, how to provide information and how it should be collated and reported.

• How to present the results in reporting and communication.

• Which data is necessary for calculation and application of the standard.

This standard cover sustainability assessment in general for civil engineering work and not just LCA in particular. Unlike the EN 15804, this standard also includes social and economic aspects [9].

2.6.2 Certification

CEEQUAL^R is an evidence-based sustainability assessment tool that works for civil engineering, infrastructure, landscaping and works in public spaces. It con- tains ratings and schemes with rewards that encourages companies to go beyond the minimum of legal, environmental and social performance in their work.

In the process, self-assessment is used. The project and contract strategies are assessed by special CEEQUAL^R trained consultants. The performance on environmental and social issues are arranged in nine sectors. This encourages companies to consider the sustainability issues they face at the most appropriate time of the project. The assessment is verified externally by CEEQUAL^R. When the assessment score is ratified, the contract team is rewarded based on the percentage score on the scale of "Pass – Good – Very Good – Excellent" [10].

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3 Experimental Method

3.1 Application of European Level Standards on the Mälar Project

A working copy of the possibly new European level standard for sustainability assessment of construction works were used to identify stages of the life cycle of the retaining walls. Economic and social performance were left out in this study which focuses only on environmental performance.

3.1.1 Specification of the Object of Assessment

The modules for the different life stages were constructed after those used while making an EPD. A complete declaration of each module can be found in EN 15804.

The system boundary was constructed after the goal and intended use of the study, stated in the beginning of this report.

3.1.2 Quantification and Selection of Data

All data for the modules were collected from existing EPDs for the different materials used in the retaining walls, from EPDs of similar products or estimated values.

The values for total material amounts were based on what is used in the project up to this date and what is projected to be used in future works. The values were given by the supervisor Oscar Lindroth (Züblin, Environment and Sustainability).

Scenarios were developed for the construction stage where estimated values were given by supervisor Rutger Gyllenram (Unit of Process, Department of Ma- terial Science and Engineering (MSE), KTH). The vehicles working at the construction site were estimated to consume 10 litres of diesel per hour to install the materials. I litre of diesel were estimated to emit 30 kg CO₂ eq. It was also estimated that there was a working time of 1.5 hours per tonne for steel and 1.5 hours per m³ for concrete. It was also assumed that the working hours for demolition was the same as for construction. It was also assumed that the distance from the construction site to disposal are the same as the distance from the manufacturer to the construction site.

The use stage was considered to not have any impact since no maintenance or resource use is needed during the use stage.

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4 Results

The constructed framework represents a model for an LCA, mainly focused on the LCI phase. This model is intended to be completed with more data later by Züblin Scandinavia AB.

4.1 System boundaries

The object of assessment is a part of the refurbishment taking place within the Mälar Project, meaning the retaining walls that are constructed along the channel that leads up to Södertälje Harbour. A principle sketch can be seen in Figure 3.

Figure 3: A principle sketch of the retaining walls constructed along the channels near Södertälje Harbour [11].

After dredging, the 25 m deep walls are installed for a total of 3 km along the channel. The function of the walls is to prevent the side of the channel to collapse and straighten the bends near the bottom. The reference study period is the same as the required service life, which is 100 years. The walls are protected by corrosion by dimension and no refurbishment is needed during its service life.

What is included for each module of the different stages of the life cycle can be seen in Table 1.

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Table 1: Description of the life cycle stages of the retaining walls and system boundaries for the object of assessment

Module Stage Description

A1-A3 Product Processes from extracting the raw materials to manufacturing the products used in the construction.

A4-A5 Construction process

Transport of the materials and products from the manufacturer to the civil engineering work site (A4). Machine hours for installing the retaining walls (A5).

B1-B7 Use The modules of the use stage are estimated to not have any impacts since no maintenance is needed and the function and operation of the walls do not require any specific energy or water use etc.

C1-C4 End of life Machine hours for the on-site deconstruction process (C1), transportation to disposal (C2), other processes to reach the end-of-waste estate (C3), and Possible post-transportation treatment that is necessary before disposal (C4).

D1 Benefits and

loads beyond the system boundary

Potential resources covering reuse, recycling and energy recovery of flows of secondary products, materials and fuels with economic value or which reached the end of waste stage that exit the system boundary.

4.2 Life Cycle Inventory of the Retaining Walls

This section is divided into two parts. First the collected data and data quality is described in more detail before the results are presented. All modules and materials covered in the LCI framework can be seen in Table 2 to Table 6.

4.2.1 Quantification

The functional unit is 1 tonne for steel and 1 m³for concrete. The impact category used in this study is global warming potential which is measured in kg CO₂ eq.

The example data for the anchors and the sheet piling is taken from an EPD made by Rukki [12] and from Gerdau for the rebars [13]. Example data for the chapping beam is from an EPD made by Betongforum [14].

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Table 2: Collected LCI data for the retaining walls regarding module A1 to A3, repre- senting the product stage.

Material Description Amount kg CO₂ eq.

Black steel Anchors 840 2710

Steel Sheet piling 8400 2710

Steel Rebars 930 767

Concrete Capping beam 11300 303

Table 3: Collected LCI data for the retaining walls regarding module A4 which covers transport from the manufacturer to the construction site. No data on this module is presented for the rebars.

Material Description Amount kg CO2 eq.

Black steel Anchors 840 0.02

Steel Sheet piling 8400 0.02

Steel Rebars 930 -

Concrete Capping beam 11300 4.58

Table 4: Collected LCI data for the retaining walls regarding module A5 which includes the installation process. This module covers the machine hours for installing the materials at the construction site. This module is completely scenario based.

Material Amount kg CO₂ eq.

Steel (total) 10170 45

Concrete 11300 45

Table 5: Collected LCI data for the retaining walls regarding module C1 and C2. These modules are estimated to reach the same values asA4 and A5.

Material Amount kg CO2 eq.

Steel (total) 10170 45

Concrete 11300 45

Table 6: Collected LCI data for the retaining walls regarding module D, covering benefits beyond the system boundary and the reuse/recovery/recycling potential. Data is only collected for steel and taken from the EPD made by Ruukki.

Material Description Amount kg CO₂ eq.

Black steel Anchors 840 -1300

Steel Sheet piling 8400 -1300

Steel Rebars 930 -

Concrete Capping beam 11300 -

4.2.2 Results

Table 7 and Table 8 shows the global warming potential over the life cycle of the construction materials, concrete and steel. The functional unit is 1 tonne for steel and 1 m³ for concrete. The weight of 1 m³ concrete is 2388,5 kg [14].

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Table7:Environmentalimpactsfromsteel.GWP=GlobalWarmingPotential(ClimateChange). A1-A3A4A5B1B2B3B4B5B6B7C1C2C3C4D Unit Product stage

T ransp ortto

site Constructioninstallation

Use Maintenance Repair Replacement Refurbishment

Operational energyuse

Operational water

use

Demolition

T ransp ort

W aste processin

g

Disposal Reuse/recov

ery/recycling

kgCO2eq.2532.320.02450.000.000.000.000.000.000.00450.02---1300

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Table8:Environmentalimpactsfromconcrete.GWP=GlobalWarmingPotential(ClimateChange). A1-A3A4A5B1B2B3B4B5B6B7C1C2C3C4D IndicatorUnit Product stage

T ransp ortto

site Constructioninstallation

Use Maintenance Repair Replacement Refurbishment

Operational energyuse

Operational water

use

Demolition

T ransp ort

W aste processin

g

Disposal Reuse/recov

ery/recycling

GWPkgCO2eq.3034.58450.000.000.000.000.000.000.00454.58---

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4.2.3 Interpretation

The distribution of the environmental impact of the materials, concrete and steel, used in the retaining walls for the different modules is shown in Figure 4 and Fig- ure 5. Most of the impact comes from the product stage. For steel, 97 percent of total impact came from this stage. It is also shown that 50 percent of the impact could be reduced in module D, potentially for later systems. No data for this module was found for concrete. The product stage for concrete is also dominating the impact with 75 percent of total.

Figure 4: Distribution of the environmental impact (GWP) for the steel within the retaining walls.

Figure 5: Distribution of the environmental impact (GWP) for the concrete within the

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5 Discussion

5.1 Sustainability Assessment

It has not been studied if the data from this report is enough for gaining scores to CEEQUAL^R. There is little requirement from CEEQUAL^R on how to conduct an LCA other than referring to the ISO standards. An EPD is technically the result part of an LCA built on these standards so the question is if this is enough or if it must be completed with more data during the entire life cycle. An EPD usually only cover the product stage. However, there was little interest from Züblin to develop scenarios for the later life stages. The focus on how to lower the impact were based on using alternative materials. This perspective could be backed up by the results showing that the main impact came from the product stage.

5.2 Collection of Data and Reliability

Züblin has not worked with LCA before, which made the process of collecting data very time consuming. Since there are no routines today for collecting EPDs, more work had to be done to find relevant data. Some of the suppliers were very helpful and sent documents upon request while other did not respond. It was however quite easy to find EPDs for similar materials, such as for the rebars. Although it is better to use as specific data as possible.

There is little consistency in the collection of data in this study and the reliability of the results could be questioned. There are also a lot of assumptions that effects the results. The focus of this thesis was more about how to find a method for Züblin on how to conduct an LCA.

There are also uncertainties on how to describe benefits beyond the system boundaries. For example, the renovation of the lock in Södertälje will allow for larger ship to pass the harbour, meaning that the road network should be unloaded. The retaining walls may also lead to fewer accidents. It is however hard to make assumptions and make scenarios around this. If other scenarios are to be constructed by Züblin, it must be stated clearly which assumptions that are made.

The materials are measured in different units and have different functions within the construction and should therefore not be compared with respect to each other.

This study also lacks other impact categories which should be completed later.

Environmental performance cannot be interpenetrated only by global warming potential since there may be other impacts as well and no decisions should be made on these results. The same structure of this work could be followed by Züblin to collect and present data for other impact categories as well.

5.3 Reporting the Results of the LCA

There is no definite way for Züblin to present and report the final data. The ISO standards describes the basic principles, but it is up to Züblin to decide the format of reporting from their requirements and intended use. It was found useful to use the structure of the modules described in EN 15804 for Table 7 and Table 8 to identify all relevant sources that contribute to the results.

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5.4 Responsibility and Benefits

There are a lot of different parts and interests involved in a project of this magni- tude. The question is who should be responsible to report this data and who will benefit from it. With the intensifying debate on climate change it may be requirements on European level or clients may ask for data when choosing entrepreneurs.

There are a lot of science and frameworks for the matter, but the companies need bigger motivators to conduct LCA with reliable results.

For the manufacturer though, there seems to be a way of marketing to conduct EPDs for the materials, in the future it may also be a competitive tool for the entrepreneurs if clients ask for it more frequently.

5.5 Ethical and Social Aspects

Since the world leaders has agreed to work to limit global temperature rise to well below 2 degrees centigrade, it is important to develop tools to evaluate sustainability performance. If we do not keep track of the impacts of future solutions and the amount of CO₂ released into the air, temperatures are at the risk of rising.

Climate change is a global challenge that does not respect national borders, and the poorest and most vulnerable may possibly suffer the most. It is therefore important to use the tools to evaluate sustainability where it is possible to identify solutions for lowering the impact of a product or a system. What does not get measured runs a risk of being neglected and the whole life cycle, and all relevant impacts caused by the solution of a product or a system should be considered.

Therefore, the system perspective of LCA can be used as a tool to identify future solutions.

The methodology of LCA could be of importance for professionals, responsible for creating solutions for the future. In today’s global economy, it could also be important for everybody else as stakeholders, consumers, and voters to access information about the impacts of a product or a system. If relevant information is not available, it will be harder to make the decisions that supports sustainable development.

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6 Conclusions

LCA is a broad field with many directives and standards. The ISO standards are very general, and an extension of the directives may be used. For example, the ISO 14040 states that impact categories should be chosen in the goal and scope definition, but it does not state which ones. EN 15804 is an extension of the ISO standards, and describes which impact categories that are relevant for construction materials. The phase of collecting data for the impact categories were the most time and resource consuming part of this work and a lot of the data were hard to obtain. The following conclusions were drawn around creating an LCI framework for assessing the retaining walls;

• Further directives then the ISO standards are needed for the methodology of creating a full LCA, depending on the intended use of the study.

• The phase of collecting data could be an integrated part of the companies working model to make the process easier in the future.

• EPDs are a good source of example data but it is important to keep track on how the data were collected in order to understand the reliability.

• It is accepted to develop scenarios, if the assumptions and estimations are clearly described.

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7 Recommendations

The following recommendations is presented to make the process of collecting data easier in the future for Züblin Scandinavia AB. Recommendations on Suggestions on how to gain more scores from CEEQUAL^R and how to continue the work of LCA is also presented.

• It could be set as a routine to ask for EPDs or other relevant documentation while purchasing the materials. This data could be stored in a separate archive which makes the process of collecting data for LCA easier in the future.

• LCA only targets environmental aspects within a product system. The new standard from CEN could be used in the future to cover social and economic aspects as well. This could also lead to higher scores from CEEQUAL^R in other areas.

• The modules could be expanded a lot more. A4 for example, could also include transport of persons and equipment to the construction site.

• Transport of the materials to the construction site and to disposal could be updated with more accurate values if the distances are known by Züblin. It may also be possible to achieve more accurate values for the machine hours of installing the materials if these are tracked.

• If the retaining walls are meant to be demolished and sent to disposal, data on C3 and C4 could be complemented.

• Other indicators described in EN 15804 should also be included in the LCA and data considering other impact categories should also be collected.

• In order make a full LCA, Züblin Scandinavia AB needs to consider the intended use of the study and make a complete goal and scope definition.

Depending on this, different directives could be chosen.

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8 Acknowledgements

I would like to thank my supervisor, Rutger Gyllenram at the Unit of Process, Department of MSE, KTH, for guiding me and providing me with insight about LCA and the standardisation processes within the subject. I would also like to thank my supervisor Oscar Lindroth, Environment and Sustainability, Züblin, for his help to give information about the project and Jasmine Andrén, Head of Sustainability and IQM, Züblin, for giving insight of the routines and sustainability work of Züblin.

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9 References

[1] un.org, ’The Sustainable Development Agenda’. [Online]. Available:

https://www.un.org/sustainabledevelopment/development-agenda/. [Ac- cessed: 09- May- 2019].

[2] un.org, ’Goal 13: Take urgent action to combat climate change and its impacts’. [Online]. Available:

https://www.un.org/sustainabledevelopment/climate-change-2/. [Accessed:

09- May- 2019].

[3] sjofartsverket.se, ’Mälarprojektet’, 2019. [Online]. Available:

http://www.sjofartsverket.se/malarprojektet. [Accessed: 09- May- 2019].

[4] [Online]. Available: https://zueblin.se/start. [Accessed: 09- May- 2019].

[5] M. Hauschild, R. Rosenbaum and S. Irving Olsen. Life Cycle Assessment:

Theory and Practise. Cham: Springer International Publishing, 2018. [On- line]. Available: https://www.springer.com/gp/book/9783319564746. [Ac- cessed: 22- May- 2019]

[6] EN 15804:2012: Sustainability of construction works — Environmental product declarations — Core rules for the product category of construction products.

[7] SS-EN ISO 14040:2006: Environmental management – Life cycle assessment – Requirements and guidelines.

[8] European Commission - Joint Research Centre - Institute for Environ- ment and Sustainability: International Reference Life Cycle Data Sys- tem (ILCD) Handbook - General guide for Life Cycle Assessment - De- tailed guidance. First edition March 2010. EUR 24708 EN. Luxembourg:

Publications Office of the European Union, 2010. [Online]. Available:

https://eplca.jrc.ec.europa.eu/ilcdHandbook.html. [Accessed: 22- May- 2019]

[9] Working copy, not published: CEN. Sustainability of construction works — Civil engineering works sustainability assessment methodology.

[10] CEEQUAL^R, An introduction to CEEQUAL^R: How, when, and why to use CEEQUAL^R. 2018 [Online]. Available: http://www.CEEQUAL.com/about/.

[Accessed: 07- May- 2019]

[11] Principle sketch provided by the supervisor, Oscar Lindroth, Environment and Sustainability, Züblin Scandinavia AB.

[12] Ruukki Construction Oy. Welded and coated sections, trusses and beams made of hot-rolled plate, sheet and coil. Helsinki:

The Norwegian EPD Foundation, 2015. [Online]. Available:

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[13] Gerdau. Reinforcing Steel Bar. Chile: EPD International AB, 2017. [Online].

Available: https://www.environdec.com/Detail/?Epd=10801. [Accessed: 22- May- 2019]

[14] Betongindustri AB. FrostBI Anläggning FA. Næringslivets Stiftelse for Miljødeklarasjoner, 2019. [Online]. Available: https://www.epd-norge.no/.

[Accessed: 22- May- 2019]

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