2nd generation concrete construction: carbon footprint accounting

Purpose – Construction contractors and facility managers are being challenged to minimize the carbon footprint. Life cycle carbon‐equivalent (CO2‐e) accounting, whereby the potential emissions of greenhouse gases due to energy expenditure during construction and subsequent occupation of built infrastructure, generally ceases at the end of the service life. However, following demolition, recycling of demolition waste that becomes incorporated into 2nd generation construction is seldom considered within the management of the carbon footprint. This paper aims to focus on built concrete infrastructure, particularly the ability of recycled concrete to chemically react with airborne CO2, thereby significantly influencing CO2‐e estimates.

Design/methodology/approach – CO2‐e estimates were made in accordance with the methodology outlined in the Australian National Greenhouse Accounts (NGA) Factors and were based on the energy expended for each life cycle activity from audited records. Offsets to the CO2‐e estimates were based on the documented ability of concrete to chemically react with airborne carbon dioxide (“carbonation”) and predictions of CO2 uptake by concrete and recycled concrete was made using existing predictive diffusion models. The author's study focused on a built concrete bridge which was demolished and recycled at the end of the service life, and the recycled concrete was utilized towards 2nd generation construction. The sensitivity of CO2‐e and carbonation estimates were tested on several different types of source demolition waste as well as subsequent construction applications using recycled concrete (RCA). Whole‐of‐life CO2‐e estimates, including carbonation of RCA over the 1st and 2nd generations, were estimated and contrasted with conventional carbon footprints that end at the conclusion of the 1st generation.

Findings – Following demolition, CO2 capture by RCA is significant due to the more permeable nature of the crushed RCA compared with the original built infrastructure. RCA also has considerably greater exposed surface area, relative to volume, than a built concrete structure, and therefore more highly exposed surface to react with CO2: it therefore carbonates more comprehensively. CO2‐e estimates can be offset by as much as 55‐65 per cent when including the contribution of carbonation of RCA built within 2nd generation infrastructure. Further offsets are achievable using blended fly ash or slag cement binders; however, this study has focused on concrete composed of 100 per cent OPC binders and the effects of RCA.

Originality/value – Construction project estimates of life cycle CO2‐e emissions should include 2nd generation applications that follow the demolition of the 1st generation infrastructure. Life cycle estimates generally end at the time of demolition. However, by incorporating the recycled concrete demolition waste into the construction of 2nd generation infrastructure, the estimated CO2‐e is significantly offset during the 2nd generation life cycle by chemical uptake of CO2 (carbonation). This paper provides an approach towards inclusion of 2nd generation construction applications into whole‐of‐life estimates of CO2‐e.

Green marketing strategies

This chapter presents the fundamentals of “green” marketing by drawing on traditional marketing theory as well as researchfocused on green marketing context. It discusses five critical areas in green marketing. The first critical area stems from green marketingtheory and practice that examines the logic for reducing the environmental impact of value creation and exchange. The second criticalarea highlights green marketing strategy that focuses on achieving organizational goals in ways that can reduce or eliminate negativeimpacts on the natural environment. The third critical area examines the green marketing mix that accounts for green products, greendistribution, green pricing, and green promotion. By using traditional marketing concepts, the chapter identifies how the entiremarketing mix elements should consistently provide a complete green product offering. Green products and processes need to beresearched, designed, and manufactured to include environmentally safe ingredients and components. Products need to be strategicallypriced to reflect their green values, distributed in the green chain channels and displayed effectively to highlight their status, and accuratelycommunicated to consumers and stakeholders. The fourth critical area illustrates governance and control. It shows how theholistic transformation toward greening the organization requires organizational culture change to gain support within and outside thefirm to ensure environmental issues are appropriately considered. These can be assessed by using existing management mechanisms,such as environmental management systems and/or triple bottom line management, which ensure best practice and continuousimprovements to occur. Lastly, the chapter discusses the future of green marketing and the direction that businesses need to take if theyseek to be sustainable.