Identification of key environmental issues for building materials

Manufacture, construction and use of buildings and building materials make a significant environmental impact internally (inside the building), locally (neighbourhood) and globally. Life cycle assessment (LCA) methodology is being applied for evaluating the environmental impact of building/or building materials. One of the major applications of LCA is to identify key issues of a product system from cradle to grave. Key issues identified in an LCA lead one to the right direction in assessing the environmental aspects of a product system and help to identify the areas for improvement of the environmental performance of a product as well. The purpose of this paper is to suggest two methods for identifying key issues using an integrated tool (LCADesign), which has been developed to provide a method of determining the best alternative for reducing environmental impacts from a building or building materials, and compare both methods in the case study. This paper assists the designers or marketers related to building or building materials in their decision making by giving information on activities or alternatives which are identified as key issues for environmental impacts.

Life cycle inventory for Australian building materials

This paper discusses challenges to developers of a national Life Cycle Inventory (LCI) database on which to base assessment of building environmental impacts and a key to development of a fully integrated eco-design tool created for automated eco-efficiency assessment of commercial building design direct from 3D CAD. The scope of this database includes Australian and overseas processing burdens involved in acquiring, processing, transporting, fabricating, finishing and using metals, masonry, timber, glazing, ceramics, plastics, fittings, composites and coatings. Burdens are classified, calculated and reported for all flows of raw materials, fuels, energy and emissions to and from the air, soil and water associated with typical products and services in building construction, fitout and operation. The aggregated life cycle inventory data provides the capacity to generate environmental impact assessment reports based on accepted performance indicators. Practitioners can identify hot spots showing high environmental burdens of a proposed design and drill down to report on specific building components. They can compare assessments with case studies and operational estimates to assist in eco-efficient design of a building, fitout and operation.

A review of benchmarking in carbon labelling schemes for building materials

As one of the largest sources of greenhouse gas (GHG) emissions, the building and construction sector is facing increasing pressure to reduce its life cycle GHG emissions. One central issue in striving towards reduced carbon emissions in the building and construction sector is to develop a practical and meaningful yardstick to assess and communicate GHG results through carbon labelling. The idea of carbon labelling schemes for building materials is to trigger a transition to a low carbon future by switching consumer-purchasing habits to low-carbon alternatives. As such, failing to change purchasing pattern and behaviour can be disastrous to carbon labelling schemes. One useful tool to assist customers to change their purchasing behaviour is benchmarking, which has been very commonly used in ecolabelling schemes. This paper analyses the definition and scope of benchmarking in the carbon labelling schemes for building materials. The benchmarking process has been examined within the context of carbon labelling. Four practical issues for the successful implementation of benchmarking, including the availability of benchmarks and databases, the usefulness of different types of benchmarks and the selection of labelling practices have also been clarified.

Estimating indoor air quality using integrated 3D CAD building models

The indoor air quality (IAQ) in buildings is currently assessed by measurement of pollutants during building operation for comparison with air quality standards. Current practice at the design stage tries to minimise potential indoor air quality impacts of new building materials and contents by selecting low-emission materials. However low-emission materials are not always available, and even when used the aggregated pollutant concentrations from such materials are generally overlooked. This paper presents an innovative tool for estimating indoor air pollutant concentrations at the design stage, based on emissions over time from large area building materials, furniture and office equipment. The estimator considers volatile organic compounds, formaldehyde and airborne particles from indoor materials and office equipment and the contribution of outdoor urban air pollutants affected by urban location and ventilation system filtration. The estimated pollutants are for a single, fully mixed and ventilated zone in an office building with acceptable levels derived from Australian and international health-based standards. The model acquires its dimensional data for the indoor spaces from a 3D CAD model via IFC files and the emission data from a building products/contents emissions database. This paper describes the underlying approach to estimating indoor air quality and discusses the benefits of such an approach for designers and the occupants of buildings.

Effect of nano-silica on the mechanical and transport properties of lightweight concrete

This paper investigated the influence of nano-silica (NS) on the mechanical and transport properties of lightweight concrete (LWC). The resistance of LWC to water and chloride ions penetration was enhanced despite strength marginally increased. Water penetration depth, moisture sorptivity, chloride migration and diffusion coefficient was reduced by 23% and 49%, 23% and 10%, 5% and 0%, 22% and 12% compared to the two reference LWC mixes (pure cement and 60% slag blended cement), respectively with 1% NS. Such improvements were attributed to more compact microstructures because the micropore system was refined and the interface between aggregates and paste was enhanced.

Defining reference service life : an open innovation approach

The endeavour to obtain estimates of durability of components for use in lifecycle assessment or costing and infrastructure and maintenance planning systems is large. The factor method and the reference service life concept provide a very valuable structure, but do not resolve the central dilemma of the need to derive an extensive database of service life. Traditional methods of estimating service life, such as dose functions or degradation models, can play a role in developing this database, however the scale of the problem clearly indicates that individual dose functions cannot be derived for each component in each different local and geographic setting. Thus, a wider range of techniques is required in order to devise reference service life. This paper outlines the approaches being taken in the Cooperative Research Centre for Construction Innovation project to predict reference service life. Approaches include the development of fundamental degradation and microclimate models, the development of a situation-based reasoning ‘engine’ to vary the ‘estimator’ of service life, and the development of a database on expert performance (Delphi study). These methods should be viewed as complementary rather than as discrete alternatives. As discussed in the paper, the situation-based reasoning approach in fact has the possibility of encompassing all other methods.

Strengthening of circular hollow steel tubular sections using high modulus CFRP sheets

This paper describes the behaviour of very high strength (VHS) circular steel tubes strengthened by carbon fibre reinforced polymer (CFRP) and subjected to axial tension. A series of tests were conducted with different bond lengths and number of layers. The distribution of strain through the thickness of CFRP layers and along CFRP bond length was studied. The strain was found to generally decrease along the CFRP bond length far from the joint. The strain through the thickness of the CFRP layers was also found to decrease from bottom to top layer. The effective bond length for high modulus CFRP was established. Finally empirical models were developed to estimate the maximum load for a given CFRP arrangement.

Characterisation and source identification of selected pollutants in house dust

House dust is a heterogeneous matrix, which contains a number of biological materials and particulate matter gathered from several sources. It is the accumulation of a number of semi-volatile and non-volatile contaminants. The contaminants are trapped and preserved. Therefore, house dust can be viewed as an archive of both the indoor and outdoor air pollution. There is evidence to show that on average, people tend to stay indoors most of the time and this increases exposure to house dust. The aims of this investigation were to: " assess the levels of Polycyclic Aromatic Hydrocarbons (PAHs), elements and pesticides in the indoor environment of the Brisbane area; " identify and characterise the possible sources of elemental constituents (inorganic elements), PAHs and pesticides by means of Positive Matrix Factorisation (PMF); and " establish the correlations between the levels of indoor air pollutants (PAHs, elements and pesticides) with the external and internal characteristics or attributes of the buildings and indoor activities by means of multivariate data analysis techniques. The dust samples were collected during the period of 2005-2007 from homes located in different suburbs of Brisbane, Ipswich and Toowoomba, in South East Queensland, Australia. A vacuum cleaner fitted with a paper bag was used as a sampler for collecting the house dust. A survey questionnaire was filled by the house residents which contained information about the indoor and outdoor characteristics of their residences. House dust samples were analysed for three different pollutants: Pesticides, Elements and PAHs. The analyses were carried-out for samples of particle size less than 250 µm. The chemical analyses for both pesticides and PAHs were performed using a Gas Chromatography Mass Spectrometry (GC-MS), while elemental analysis was carried-out by using Inductively-Coupled Plasma-Mass Spectroscopy (ICP-MS). The data was subjected to multivariate data analysis techniques such as multi-criteria decision-making procedures, Preference Ranking Organisation Method for Enrichment Evaluations (PROMETHEE), coupled with Geometrical Analysis for Interactive Aid (GAIA) in order to rank the samples and to examine data display. This study showed that compared to the results from previous works, which were carried-out in Australia and overseas, the concentrations of pollutants in house dusts in Brisbane and the surrounding areas were relatively very high. The results of this work also showed significant correlations between some of the physical parameters (types of building material, floor level, distance from industrial areas and major road, and smoking) and the concentrations of pollutants. Types of building materials and the age of houses were found to be two of the primary factors that affect the concentrations of pesticides and elements in house dust. The concentrations of these two types of pollutant appear to be higher in old houses (timber houses) than in the brick ones. In contrast, the concentrations of PAHs were noticed to be higher in brick houses than in the timber ones. Other factors such as floor level, and distance from the main street and industrial area, also affected the concentrations of pollutants in the house dust samples. To apportion the sources and to understand mechanisms of pollutants, Positive Matrix Factorisation (PMF) receptor model was applied. The results showed that there were significant correlations between the degree of concentration of contaminants in house dust and the physical characteristics of houses, such as the age and the type of the house, the distance from the main road and industrial areas, and smoking. Sources of pollutants were identified. For PAHs, the sources were cooking activities, vehicle emissions, smoking, oil fumes, natural gas combustion and traces of diesel exhaust emissions; for pesticides the sources were application of pesticides for controlling termites in buildings and fences, treating indoor furniture and in gardens for controlling pests attacking horticultural and ornamental plants; for elements the sources were soil, cooking, smoking, paints, pesticides, combustion of motor fuels, residual fuel oil, motor vehicle emissions, wearing down of brake linings and industrial activities.

Green buildings for greying people : a case study of a retirement village in Australia

Purpose With an increasingly ageing population and widespread acceptance of the need for sustainable development in Australia, the demand for green retirement villages is increasing. This paper aims to identify the critical issues to be considered by developers and practitioners when embarking on their first green residential retirement project in Australia. Design/methodology/approach In view of the lack of adequate historical data for quantitative analysis, a case study approach is employed to examine the successful delivery of green retirement villages. Face-to-face interviews and document analysis were conducted for data collection. Findings The findings of the study indicate that one of the major obstacles to the provision of affordable green retirement villages is the higher initial costs involved. However, positive aspects were identified, the most significant of which relate to: the innovative design of site and floor plans; adoption of thermally efficient building materials; orientation of windows; installation of water harvesting and recycling systems, water conservation fittings and appliances; and waste management during the construction stage. With the adoption of these measures, it is believed that sustainable retirement development can be achieved without significant additional capital costs. Practical implications The research findings serve as a guide for developers in decision making throughout the project life-cycle when introducing green features into the provision of affordable retirement accommodation. Originality/value This paper provides insights into the means by which affordable green residential retirement projects for aged people can be successfully completed.

Introducing sustainability assessment to civil infrastructure projects & assets

Civil infrastructure plays a key role in supporting and improving current way of life. However, the assets can have a large impact on the region around them, which are both positive (usually for the purpose they are built) and negative (consequences and unintended effects). There is an increasing trend for society to place an importance on the role of sustainability to ensure that there is a world suitable for future generations. In order to ensure that the world for future generations is in the best possible condition it is increasingly important to look at integrating sustainability outcomes into the way industry operates, including the infrastructure industry. It is therefore important to undertake sustainability assessment of civil infrastructure projects. By having organisations take on sustainability assessments of civil infrastructure assets both during construction and in operation, the industry can assist to drive outcomes and results that will benefit society and future generations and make their own operations more efficient.

Critical Factors for Sustainable Post Natural Disaster Reconstruction : Chinese Data

While scientists continue to explore the level of climate change impact to new weather patterns and our environment in general, there have been some devastating natural disasters worldwide in the last two decades. Indeed natural disasters are becoming a major concern in our society. Yet in many previous examples, our reconstruction efforts only focused on providing short-term necessities. How to develop resilience in the long run is now a highlight for research and industry practice. This paper introduces a research project aimed at exploring the relationship between resilience building and sustainability in order to identify key factors during reconstruction efforts. From extensive literature study, the authors considered the inherent linkage between the two issues as evidenced from past research. They found that sustainability considerations can improve the level of resilience but are not currently given due attention. Reconstruction efforts need to focus on resilience factors but as part of urban development, they must also respond to the sustainability challenge. Sustainability issues in reconstruction projects need to be amplified, identified, processed, and managed properly. On-going research through empirical study aims to establish critical factors (CFs) for stakeholders in disaster prone areas to plan for and develop new building infrastructure through holistic considerations and balanced approaches to sustainability. A questionnaire survey examined a range of potential factors and the subsequent data analysis revealed six critical factors for sustainable Post Natural Disaster Reconstruction that include: considerable building materials and construction methods, good governance, multilateral coordination, appropriate land-use planning and policies, consideration of different social needs, and balanced combination of long-term and short-term needs. Findings from this study should have an influence on policy development towards Post Natural Disaster Reconstruction and help with the achievement of sustainable objectives.