Eco-efficient Construction and Building Materials

Life Cycle Assessment (LCA), Eco-Labelling and Case Studies

Fernando Pacheco-Torgal, Luisa F. Cabeza, Joao Labrincha, Aldo Giuntini de Magalhaes

• Publisher: Woodhead Publishing
• Year: 2014
• Print ISBN: 9780857097675
• eBook ISBN: 9780857097729
• Topic: Technology & Engineering
• Subtopic: Architecture Methods & Materials
• Index: Technology & Engineering

Eco-efficient Construction and Building Materials reviews ways of assessing the environmental impact of construction and building materials. Part one discusses the application of life cycle assessment (LCA) methodology to building materials as well as eco-labeling. Part two includes case studies showing the application of LCA methodology to different types of building material, from cement and concrete to wood and adhesives used in building. Part three includes case studies applying LCA methodology to particular structures and components. - Reviews ways of assessing the environmental impact of construction and building materials - Provides a thorough overview, including strengths and shortcomings, of the life cycle assessment (LCA) and eco-labeling of eco-efficient construction and building materials - Includes case studies showing the application of LCA methodology to different types of building material, from cement and concrete to wood and adhesives used in building

1

Introduction to the environmental impact of construction and building materials

F. Pacheco-Torgal University of Minho, Portugal

Abstract

Earth’s natural resources are finite and face increasing human pressure. Over the last few decades, concern has been growing about resource efficiency and the environmental impact of material consumption. The construction industry is responsible for the consumption of a relevant part of all produced materials, however, only recently has this industry started to worry about its environmental impacts. This chapter highlights relevant landmarks on sustainable development, materials efficiency and on the assessment of the environmental impact of construction products. An overview on the European Construction Products Regulation (CPR) enforced since the 1 July 2013 is given followed by an outline of the book.

Key words

sustainable development

materials efficiency

environmental impact

LCA

eco-labels

product self-declarations

1.1 Introduction

Four decades ago, several investigators used a computer model based on the fixed-stock paradigm to study the interactions between population, food production, industrial production, pollution and the consumption of non-renewable resources. They predicted that during the 21st century, the Earth’s capacity would be exhausted, resulting in the collapse of human civilisation as we know it (Meadows et al., 1972). Two decades later, an update of this study was published showing that some limits had already been crossed (Meadows et al., 1992).Whilst the particular assumptions and predictions of such studies have been questioned, there is general agreement that may of the Earth’s key resources are finite and must be conserved. As a consequence, the concept of ‘sustainable development’ gained international recognition through the landmark Brundtland Report ‘Our common future’ (Brundtland, 1987).

Some authors (Clayton, 2001; Choi and Pattent, 2001) have argued that ‘sustainable development’ is an oxymoron: we cannot have development/growth for the entire world population and at the same time, expect this development to be compatible with protection of the environment. The fact that there have been serious environmental disasters in Europe, such as Stava (1985), Aznalcollar (1998), Baia Borsa (2000) and Kolontar (2010), despite the region’s relatively high environmental standards, illustrates this problem. The challenge is also highlighted by continued growth in materials use. Europe has the world’s highest net imports of resources per person, and its open economy relies heavily on imported raw materials and energy. In 2007 the total amount of material directly used in the EU economy was more than 8 billion tonnes (COM, 2011a).

It has been estimated that global materials use increased eight-fold in the last century and that current usage is almost 60 billion tons (Gt) of materials per year (Krausmann et al., 2009). Despite this huge historic growth, some authors predict that materials demand will double by 2050 (Allwood et al., 2011). It is important to note that 40% of all materials are used by the construction industry (Kulatunga et al., 2006). The construction industry is expected to continue to grow rapidly. As an example, it is estimated that India will invest US$ 1 trillion in infrastructure between 2012 and 2017 (Chakraborty et al., 2011). In the USA, where around 27% of all highway bridges are in need of repair or replacement, the needs for infrastructure rehabilitation alone are estimated to be over US$ 1.6 trillion during the next five years, (Davalos, 2012). Wang et al. (2010) have estimated that construction activities in China consume approximately 40% of its total natural resources and around 40% of its energy and that the country will need 40 billion square metres of combined residential and commercial floor space over the next 20 years – equivalent to adding one New York City every two years (Pacheco-Torgal and Labrincha, 2013a; Pacheco-Torgal and Jalali, 2011).

The World Business Council for Sustainable Development estimates that by 2050, a four- to ten-fold increase in resource efficiency will be needed (COM, 2011a). Over the last few decades, concern has been growing about resource efficiency and the environmental impact of material consumption. As a result, the term ‘green materials’ became very popular in the construction sector. However, it was not until 2012 that the first life cycle assessment (LCA) investigations into standard structural concrete made using Portland cement started to become available (Van den Heede and De Belie, 2012; Habert et al., 2012). This is despite the fact that it is the most used construction material with output currently about 10 km³/year. In comparison, the amount of fired clay, timber, and steel used in construction represents about 2, 1.3 and 0.1 km³, respectively (Flatt et al., 2012). There is still much to investigate concerning the LCA of this material, for example incorporating recent nano and biotech approaches (Jayapalan et al., 2013; Pacheco-Torgal and Labrincha, 2013b).

1.2 Environmental impact assessment

The methodology used to assess the environmental impacts of a given material is known as ‘life cycle assessment’ (LCA) and ‘includes the complete life cycle of the product, process or activity, i.e., the extraction and processing of raw materials, manufacturing, transportation and distribution, use, maintenance, recycling, reuse and final disposal’ (SETAC, 1993). The application of LCA has been regulated internationally since 1996 under the International Standards Organisation (ISO) which classifies the existing environmental labels into three typologies – types I(eco-labels, ISO 14024), type II (product self-declarations, ISO 14021), and type III (EPDs, ISO 14025). It should be noted that in 2012, the DG Environment published the draft of a harmonised methodology for calculating of the environmental footprint of products (Del Borghi, 2013). Since the first eco-label, the German Blue Angel, was created in 1978, several others have appeared. However, some authors (Rajagopalan et al., 2012) argue that ‘the labelling of green materials is confusing and that consumers are suspicious about the environmental claims of manufacturers.’

Hauschild et al. (2013) state that the LCA standard ISO 14040-44 is rather generalised and non-specific in its requirements and offers little help to the LCA practitioner in making choices. The weighting process related to decision making as to which environmental impacts are most significant for the process or product in question remains a controversial and inexact science (Johnsen and Løkke, 2013). Other issues also remain as open questions in the LCA methodology (Feifel et al., 2010).

Other important subjects must also be taken into account in considering the future environmental impact of construction and building materials. For example, it remains to be seen if the benefits of recycling should be credited to the primary producer or to the user of recycled materials (Huang et al., 2013; Chen et al., 2010). This is a crucial issue in the context of the Revised Waste Framework Directive (WFD) 2008/98/EC (EU, 2008) which established that by 2020, the minimum recycling percentage of ‘non-hazardous’ construction and demolition wastes should be at least 70% by weight (Pacheco-Torgal et al., 2013). Improving the reuse of raw materials through greater ‘industrial symbiosis’ across the EU could save €1.4bn a year and generate €1.6bn in sales (COM, 2011a).

The simplifications of LCAs are unlikely to cope well with the increased importance of the environmental impacts of construction and building materials in the context of low energy buildings. (Kellenberger and Althaus, 2009; Blengini and Di Carlo, 2010). It should be noted that higher energy efficiency in new and existing buildings is the key for transformation of the EU’s energy system (COM, 2011b). According to the European Energy Performance of Buildings Directive (EU, 2010), all new constructions will have to be nearly zero-energy by 31 December 2020.

Current labelling schemes are only concerned with short term volatile organic compound emissions from building materials. Research on long-term emissions is therefore needed to reduce the level of uncertainty (Skaar and Jørgensen, 2012). It should be remembered that more than 100,000 new chemical compounds have been developed since 1939 and insufficient information exists for health assessments of 95% of the chemicals used in construction products (Pacheco-Torgal et al., 2012).

It is also significant that product replacement may take place over a very short period of time as occupant behaviour is influenced by societal trends. Therefore estimation methods capable of capturing consumer behaviour are a necessary step towards modelling over a lifetime (Aktas and Bilec, 2011). In future, it will be necessary to apply dynamic methods to the LCI or LCIA (Collinge et al., 20...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright page
• Contributor contact details
• Woodhead Publishing Series in Civil and Structural Engineering
• 1: Introduction to the environmental impact of construction and building materials
• Part I: Life cycle assessment (LCA), eco-labelling and procurement
• Part II: Assessing the environmental impact of construction and building materials
• Part III: Assessing the environmental impact of particular types of structure
• Index